ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Articles  (928)
  • Copernicus  (696)
  • Wiley  (123)
  • American Geophysical Union  (109)
  • American Society of Civil Engineers
  • 2015-2019  (928)
  • 2010-2014
  • 1995-1999
  • 2016  (928)
  • The Cryosphere  (504)
  • Global Biogeochemical Cycles  (123)
  • 7532
  • 92597
  • Geography  (928)
  • 1
    facet.materialart.
    Unknown
    Landfast ice thickness in the Canadian Arctic Archipelago from observations and models (2016)
    Copernicus
    Details
    Publication Date: 2016-07-13
    Description: Landfast ice thickness in the Canadian Arctic Archipelago from observations and models Stephen E. L. Howell, Frédéric Laliberté, Ron Kwok, Chris Derksen, and Joshua King The Cryosphere, 10, 1463-1475, doi:10.5194/tc-10-1463-2016, 2016 The Canadian Ice Service record of observed landfast ice and snow thickness represents one of the longest in the Arctic that spans over 5 decades. We analyze this record to report on long-term trends and variability of ice and snow thickness within the Canadian Arctic Archipelago (CAA). Results indicate a thinning of ice at several sites in the CAA. State-of-the-art climate models still have difficultly capturing observed ice thickness values in the CAA and should be used with caution.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 2
    facet.materialart.
    Unknown
    Increased nitrate and decreased δ15N–NO3− in the Greenland Arctic after 1940 attributed to North American oil burning (2016)
    Copernicus
    Details
    Publication Date: 2016-07-14
    Description: Increased nitrate and decreased δ 15 N–NO 3 − in the Greenland Arctic after 1940 attributed to North American oil burning Nathan J. Chellman, Meredith G. Hastings, and Joseph R. McConnell The Cryosphere Discuss., doi:10.5194/tc-2016-163,2016 Manuscript under review for TC (discussion: open, 0 comments) This manuscript analyzes the changing sources of nitrate deposition to Greenland since 1760 CE using a dataset consisting of sub-seasonally resolved nitrogen isotopes of nitrate and source tracers. Correlations amongst ion concentration, source tracers, and the δ 15 N–NO 3 − provide evidence of the impact of biomass burning and fossil fuel combustion emissions of nitrogen oxides and suggest that oil combustion is the likely driver of increased nitrate concentration in Greenland ice since 1940 CE.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 3
    facet.materialart.
    Unknown
    Response of seasonal soil freeze depth to climate change across China (2016)
    Copernicus
    Details
    Publication Date: 2016-07-15
    Description: Response of seasonal soil freeze depth to climate change across China Xiaoqing Peng, Oliver W. Frauenfeld, Tingjun Zhang, Kang Wang, Bin Cao, Xinyue Zhong, Hang Su, and Cuicui Mu The Cryosphere Discuss., doi:10.5194/tc-2016-129,2016 Manuscript under review for TC (discussion: open, 0 comments) Previous researches paid more attention on the permafrost, e.g. active layer thickness, soil temperature, permafrost area extent, and associated with permafrost degradation leading other changes. However, seasonally frozen ground, vast area extent, did not focus by so much attention. Here, we combined more than 800 observation station data and gridded data to investigate soil freeze depth across China. The results indicate that soil freeze depth increase with climate warming.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 4
    facet.materialart.
    Unknown
    Circumpolar polynya regions and ice production in the Arctic: Results from MODIS thermal infrared imagery for 2002/2003 to 2014/2015 with a regional focus on the Laptev Sea (2016)
    Copernicus
    Details
    Publication Date: 2016-07-22
    Description: Circumpolar polynya regions and ice production in the Arctic: Results from MODIS thermal infrared imagery for 2002/2003 to 2014/2015 with a regional focus on the Laptev Sea Andreas Preußer, Günther Heinemann, Sascha Willmes, and Stephan Paul The Cryosphere Discuss., doi:10.5194/tc-2016-133,2016 Manuscript under review for TC (discussion: open, 0 comments) Our study presents spatial and temporal characteristics of 16 prominent polynya regions over the entire Arctic basin. By using an energy balance model, we are able to derive daily thin-ice thickness distributions from satellite and atmospheric reanalysis data. All polynyas combined yield an average ice production of about 1444 km 3 per winter. Interestingly, we find distinct regional differences in calculated trends over the last 13 years. Finally, we set a special focus on the Laptev Sea region.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 5
    facet.materialart.
    Unknown
    Oceanic teleconnection for carbon dioxide (2016)
    Wiley
    Details
    Publication Date: 2016-07-23
    Description: Biogeochemical teleconnection links seemingly unrelated chemical/biological anomalies that are geographically separated by large distances. Bronselaer et al propose a new mechanism for an interhemispheric teleconnection of air-sea carbon dioxide fluxes in which the upwelling of the Southern Ocean triggers a series of perturbations leading to the alteration of the carbon uptake in the North Atlantic. The westerly wind over the Southern Ocean has a unique role in the climate system. It energizes the strongest ocean current, Antarctic Circumpolar Current, and it lifts up the carbon- and nutrient-rich deep waters all the way to the surface. It is an end point of the ocean's deep overturning circulation and associated biological carbon storage, where the excess carbon from accumulated decomposition of organic material is finally released back into the atmosphere. It is well established that the Southern Ocean upwelling regionally modulates the de-gassing of carbon dioxide there. However, its global-scale implication is not yet fully understood. What happens to the carbon uptake in the other parts of the oceans? In this volume of Global Biogeochemical Cycles, Bronselaer et al describes the chain of events that link the increased Southern Ocean wind to the ocean carbon uptake in the northern high latitudes. The authors conducted a set of computational experiments, showing that the Southern Ocean is a starting point of the oceanic teleconnection, where the excess nutrient is transported equatorward through the shallow overturning circulation. The stream of macro-nutrient then fertilizes the low-latitude productivity that eventually shifts the carbonate chemistry of the high latitude surface waters. This is an intriguing case of oceanic teleconnection, linking seemingly unrelated biogeochemical anomalies that are geographically separated by large distances. The surprising conclusion is that a stronger Southern Ocean wind increases the de-gassing of carbon dioxide in both northern and southern high latitudes. This happens because more carbon is upwelling into the northern high latitudes due to the increased low-latitude biological pump, approximately doubling the de-gassing intensity relative to the Southern Ocean response alone. There may be more surprises from the Southern Ocean.
    Print ISSN: 0886-6236
    Electronic ISSN: 1944-9224
    Topics: Biology , Chemistry and Pharmacology , Geography , Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 6
    facet.materialart.
    Unknown
    Radiocarbon dating of glacier ice (2016)
    Copernicus
    Details
    Publication Date: 2016-07-23
    Description: Radiocarbon dating of glacier ice Chiara Uglietti, Alexander Zapf, Theo M. Jenk, Sönke Szidat, Gary Salazar, and Margit Schwikowski The Cryosphere Discuss., doi:10.5194/tc-2016-160,2016 Manuscript under review for TC (discussion: open, 0 comments) A meaningful interpretation of the climatic history contained in ice cores requires a precise chronology. For dating the older and deeper part of the glaciers, radiocarbon analysis can be used, when organic matter such as plant or insect fragments is found in the ice. Since this happens rarely, a complementary dating tool is based on radiocarbon dating of the insoluble fraction of carbonaceous aerosols entrapped in the ice, allowing dating ice with ages between 200 and more than 10 000 years.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 7
    facet.materialart.
    Unknown
    Wave climate in the Arctic 1992–2014: seasonality and trends (2016)
    Copernicus
    Details
    Publication Date: 2016-07-27
    Description: Wave climate in the Arctic 1992–2014: seasonality and trends Justin E. Stopa, Fabrice Ardhuin, and Fanny Girard-Ardhuin The Cryosphere, 10, 1605-1629, doi:10.5194/tc-10-1605-2016, 2016 Satellite observations show the Arctic sea ice has decreased the last 30 years. From our wave model hindcast and satellite altimeter datasets we observe profound increasing wave heights, which are caused by the loss of sea ice and not the driving winds. If ice-free conditions persist later into fall, then regions like the Beaufort–Chukchi Sea will be prone to developing larger waves since the driving winds are strong this time of year.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 8
    facet.materialart.
    Unknown
    Microstructure representation of snow in coupled snowpack and microwave emission models (2016)
    Copernicus
    Details
    Publication Date: 2016-07-27
    Description: Microstructure representation of snow in coupled snowpack and microwave emission models Melody Sandells, Richard Essery, Nick Rutter, Leanne Wake, Leena Leppänen, and Juha Lemmetyinen The Cryosphere Discuss., doi:10.5194/tc-2016-181,2016 Manuscript under review for TC (discussion: open, 0 comments) This study looks at a wide range of options for simulating sensor signals for satellite monitoring of water stored as snow, though an ensemble of 1323 coupled snow evolution and microwave scattering models. The greatest improvements will be made with better computer simulations of how the snow microstructure changes, followed by how the microstructure scatters radiation at microwave frequencies. Snow compaction should also be considered in systems to monitor snow mass from space.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 9
    facet.materialart.
    Unknown
    Brief communication: Organochlorine pesticides in an archived firn core from Law Dome, East Antarctica (2016)
    Copernicus
    Details
    Publication Date: 2016-07-27
    Description: Brief communication: Organochlorine pesticides in an archived firn core from Law Dome, East Antarctica Marie Bigot, Mark A. J. Curran, Andrew D. Moy, Derek C. G. Muir, Darryl W. Hawker, Roger Cropp, Camilla F. Teixeira, and Susan Bengtson Nash The Cryosphere Discuss., doi:10.5194/tc-2016-178,2016 Manuscript under review for TC (discussion: open, 0 comments) Organochlorine pesticides (OCPs) were, for the first time, quantified in archived firn cores from the East Antarctic ice sheet representative of 1945–1957 C.E. and 1958–1967 C.E. The core sections were melted under high purity nitrogen atmosphere and the melt water analysed. Methods allowed quantification of hexachlorocyclohexanes, heptachlor, trans-chlordane, dieldrin and endrin. While the core presented evidence of nominal modern-use chemical contamination, indicating handling and/or storage contamination, legacy OCP concentrations and deposition rates reported are orders of magnitude lower than those from Arctic regions, lending support for their validity. The study further provides a description of equipment used and suggests adapted methods to overcome logistical challenges associated with trace organic contaminant detection in Polar Regions.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 10
    facet.materialart.
    Unknown
    Statistical indicators of Arctic sea-ice stability – prospects and limitations (2016)
    Copernicus
    Details
    Publication Date: 2016-07-29
    Description: Statistical indicators of Arctic sea-ice stability – prospects and limitations Sebastian Bathiany, Bregje van der Bolt, Mark S. Williamson, Timothy M. Lenton, Marten Scheffer, Egbert H. van Nes, and Dirk Notz The Cryosphere, 10, 1631-1645, doi:10.5194/tc-10-1631-2016, 2016 We examine if a potential "tipping point" in Arctic sea ice, causing abrupt and irreversible sea-ice loss, could be foreseen with statistical early warning signals. We assess this idea by using several models of different complexity. We find robust and consistent trends in variability that are not specific to the existence of a tipping point. While this makes an early warning impossible, it allows to estimate sea-ice variability from only short observational records or reconstructions.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 11
    facet.materialart.
    Unknown
    Greenland annual accumulation along the EGIG line, 1959–2004, from ASIRAS airborne radar and neutron-probe density measurements (2016)
    Copernicus
    Details
    Publication Date: 2016-08-03
    Description: Greenland annual accumulation along the EGIG line, 1959–2004, from ASIRAS airborne radar and neutron-probe density measurements Thomas B. Overly, Robert L. Hawley, Veit Helm, Elizabeth M. Morris, and Rohan N. Chaudhary The Cryosphere, 10, 1679-1694, doi:10.5194/tc-10-1679-2016, 2016 We demonstrate that snow accumulation rates across the Greenland Ice Sheet, determined from RADAR layers and modeled snow density profiles, are identical to ground-based measurements of snow accumulation. Three regional climate models underestimate snow accumulation compared to RADAR layer estimates. Using RADAR increases spatial coverage and improves accuracy of snow accumulation estimates. Incorporating our results into climate models may reduce uncertainty of sea-level rise estimates.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 12
    facet.materialart.
    Unknown
    Thermal impacts of engineering activities and vegetation layer on permafrost in different alpine ecosystems of the Qinghai–Tibet Plateau, China (2016)
    Copernicus
    Details
    Publication Date: 2016-08-05
    Description: Thermal impacts of engineering activities and vegetation layer on permafrost in different alpine ecosystems of the Qinghai–Tibet Plateau, China Qingbai Wu, Zhongqiong Zhang, Siru Gao, and Wei Ma The Cryosphere, 10, 1695-1706, doi:10.5194/tc-10-1695-2016, 2016 Climate warming and engineering activities have various impacts on the thermal regime of permafrost in alpine ecosystems of the Qinghai–Tibet Plateau. Using recent observations of permafrost thermal regimes along the Qinghai–Tibet highway and railway, the changes of such regimes beneath embankments constructed in alpine meadows and steppes are studied. The results show that alpine meadows on the Qinghai–Tibet Plateau can have a controlling role among engineering construction effects on permafrost beneath embankments. As before railway construction, the artificial permafrost table (APT) beneath embankments is not only affected by climate change and engineering activities but is also controlled by alpine ecosystems. However, the change rate of APT is not dependent on ecosystem type, which is predominantly affected by climate change and engineering activities. Instead, the rate is mainly related to cooling effects of railway ballast and heat absorption effects of asphalt pavement. No large difference between alpine and steppe can be identified regarding the variation of soil temperature beneath embankments, but this difference is readily identified in the variation of mean annual soil temperature with depth. The vegetation layer in alpine meadows has an insulation role among engineering activity effects on permafrost beneath embankments, but this insulation gradually disappears because the layer decays and compresses over time. On the whole, this layer is advantageous for alleviating permafrost temperature rise in the short term, but its effect gradually weakens in the long term.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 13
    facet.materialart.
    Unknown
    Combined diurnal variations of discharge and hydrochemistry of the Isunnguata Sermia outlet of the Greenland Ice Sheet give in sight on sub glacial conditions (2016)
    Copernicus
    Details
    Publication Date: 2016-07-13
    Description: Combined diurnal variations of discharge and hydrochemistry of the Isunnguata Sermia outlet of the Greenland Ice Sheet give in sight on sub glacial conditions Joseph Graly, Joel Harrington, and Neil Humphrey The Cryosphere Discuss., doi:10.5194/tc-2016-137,2016 Manuscript under review for TC (discussion: open, 0 comments) At a major outlet of the Greenland Ice Sheet in West Greenland, we find that the chemical solutes is the emerging subglacial waters are out of phase with water discharge and can spike in concentration during waning flow. This suggests that the subglacial waters are spreading out across a large area of the glacial bed throughout the day, stimulating chemical weathering beyond the major water distribution channels.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 14
    facet.materialart.
    Unknown
    Impact of Icebergs on Net Primary Productivity in the Southern Ocean (2016)
    Copernicus
    Details
    Publication Date: 2016-07-16
    Description: Impact of Icebergs on Net Primary Productivity in the Southern Ocean Shuang-Ye Wu and Shugui Hou The Cryosphere Discuss., doi:10.5194/tc-2016-166,2016 Manuscript under review for TC (discussion: open, 0 comments) The primary productivity in the Southern Ocean (SO) is limited by the amount of iron available for biological activities. Recent studies show that icebergs could be a main source of iron to the SO. Based on remote sensing data, our study shows that iceberg presence has a small, yet statistically significant, positive impact on productivity. As iceberg quantity increases, their positive influence on productivity also increases. This impact could serve as a negative feedback to the climate system.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 15
    facet.materialart.
    Unknown
    Possible groundwater dominance in the subglacial hydrology of ice sheet interiors: example at Dome C, East Antarctica (2016)
    Copernicus
    Details
    Publication Date: 2016-07-16
    Description: Possible groundwater dominance in the subglacial hydrology of ice sheet interiors: example at Dome C, East Antarctica Brad T. Gooch, Sasha P. Carter, Omar Ghattas, Duncan A. Young, and Donald D. Blankenship The Cryosphere Discuss., doi:10.5194/tc-2016-141,2016 Manuscript under review for TC (discussion: open, 0 comments) Our work investigates the potential significance of groundwater flow underneath the interior of East Antarctica where the ice doesn't rapidly melt. We attempt to describe the relationship between two hydrologic systems (water under the ice and in the ground) and how they might interact along a flow path between lakes under the ice. We find that groundwater is significant in regional water transport for melt water under the ice in areas of low melting in East Antarctica.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 16
    facet.materialart.
    Unknown
    Oxygen utilization rate (OUR) underestimates ocean respiration – a model study (2016)
    Wiley
    Details
    Publication Date: 2016-07-19
    Description: We use a simple 1D model representing an isolated density surface in the ocean and 3D global ocean biogeochemical models to evaluate the concept of computing the subsurface oceanic oxygen utilization rate (OUR) from the changes of apparent oxygen utilization (AOU) and water age. The distribution of AOU in the ocean is not only the imprint of respiration in the ocean's interior, but is strongly influenced by transport processes and eventually loss at the ocean surface. Since AOU and water age are subject to advection and diffusive mixing, it is only when they are affected both in the same way that OUR represents the correct rate of oxygen consumption. This is the case only when advection prevails or with uniform respiration rates, when the proportions of AOU and age are not changed by transport. In experiments with the 1D-tube model, OUR underestimates respiration when maximum respiration rates occur near the outcrops of isopycnals, and overestimates when maxima occur far from the outcrops. Given the distribution of respiration in the ocean, i.e. elevated rates near high latitude outcrops of isopycnals and low rates below the oligotrophic gyres, underestimates are the rule. Integrating these effects globally in three coupled ocean biogeochemical and circulation models we find that AOU-over-age based calculations underestimate true model respiration by a factor of three. Most of this difference is observed in the upper 1000 m of the ocean with the discrepancies increasing towards the surface where OUR underestimates respiration by as much as factor of four.
    Print ISSN: 0886-6236
    Electronic ISSN: 1944-9224
    Topics: Biology , Chemistry and Pharmacology , Geography , Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 17
    facet.materialart.
    Unknown
    Design of a scanning laser meter for monitoring the spatio-temporal evolution of snow depth and its application in the Alps and in Antarctica (2016)
    Copernicus
    Details
    Publication Date: 2016-07-19
    Description: Design of a scanning laser meter for monitoring the spatio-temporal evolution of snow depth and its application in the Alps and in Antarctica Ghislain Picard, Laurent Arnaud, Jean-Michel Panel, and Samuel Morin The Cryosphere, 10, 1495-1511, doi:10.5194/tc-10-1495-2016, 2016 A cost-effective automatic laser scan has been built to measure snow depth spatio-temporal variations. Deployed in the Alps and in Dome C (Antarctica), two devices acquired daily scans covering a surface area of 100–150 m 2 . The precision and long-term stability of the measurements are about 1 cm and the accuracy is better than 5 cm. These high performances are particularly suited at Dome C, where it was possible to reveal that most of the accumulation in the year 2015 stems from a single event.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 18
    facet.materialart.
    Unknown
    An ice-sheet-wide framework for englacial attenuation from ice-penetrating radar data (2016)
    Copernicus
    Details
    Publication Date: 2016-07-21
    Description: An ice-sheet-wide framework for englacial attenuation from ice-penetrating radar data T. M. Jordan, J. L. Bamber, C. N. Williams, J. D. Paden, M. J. Siegert, P. Huybrechts, O. Gagliardini, and F. Gillet-Chaulet The Cryosphere, 10, 1547-1570, doi:10.5194/tc-10-1547-2016, 2016 Ice penetrating radar enables determination of the basal properties of ice sheets. Existing algorithms assume stationarity in the attenuation rate, which is not justifiable at an ice sheet scale. We introduce the first ice-sheet-wide algorithm for radar attenuation that incorporates spatial variability, using the temperature field from a numerical model as an initial guess. The study is a step toward ice-sheet-wide data products for basal properties and evaluation of model temperature fields.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 19
    facet.materialart.
    Unknown
    Snowpack modelling in the Pyrenees driven by kilometric-resolution meteorological forecasts (2016)
    Copernicus
    Details
    Publication Date: 2016-07-23
    Description: Snowpack modelling in the Pyrenees driven by kilometric-resolution meteorological forecasts Louis Quéno, Vincent Vionnet, Ingrid Dombrowski-Etchevers, Matthieu Lafaysse, Marie Dumont, and Fatima Karbou The Cryosphere, 10, 1571-1589, doi:10.5194/tc-10-1571-2016, 2016 Simulations are carried out in the Pyrenees with the snowpack model Crocus, driven by meteorological forecasts from the model AROME at kilometer resolution. The evaluation is done with ground-based measurements, satellite data and reference simulations. Studying daily snow depth variations allows to separate different physical processes affecting the snowpack. We show the benefits of AROME kilometric resolution and dynamical behavior in terms of snowpack spatial variability in a mountain range.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 20
    facet.materialart.
    Unknown
    Nitrate uptake across biomes and the influence of elemental stoichiometry: A new look at LINX II (2016)
    Wiley
    Details
    Publication Date: 2016-07-26
    Description: Considering recent increases in anthropogenic N loading it is essential to identify the controls on N removal and retention in aquatic ecosystems because the fate of N has consequences for water quality in streams and downstream ecosystems. Biological uptake of nitrate (NO 3 - ) is a major pathway by which N is removed from these ecosystems. Here we used data from the second Lotic Intersite Nitrogen eXperiment (LINX II) in a multivariate analysis to identify the primary drivers of variation in NO 3 - uptake velocity among biomes. Across 69 study watersheds in North America, DOC:NO 3 - ratios and photosynthetically active radiation were identified as the two most important predictor variables in explaining NO 3 - uptake velocity. However, within a specific biome the predictor variables of NO 3 - uptake velocity varied, and included various physical, chemical and biological attributes. . Our analysis demonstrates the broad control of elemental stoichiometry on NO 3 - uptake velocity as well as the importance of biome-specific predictors. Understanding this spatial variation has important implications for biome-specific watershed management and the downstream export of NO 3 - , as well as for development of spatially explicit global models that describe N dynamics in streams and rivers.
    Print ISSN: 0886-6236
    Electronic ISSN: 1944-9224
    Topics: Biology , Chemistry and Pharmacology , Geography , Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 21
    facet.materialart.
    Unknown
    Connected subglacial lake drainage beneath Thwaites Glacier, West Antarctica (2016)
    Copernicus
    Details
    Publication Date: 2016-07-29
    Description: Connected subglacial lake drainage beneath Thwaites Glacier, West Antarctica Benjamin E. Smith, Noel Gourmelen, Alexander Huth, and Ian Joughin The Cryosphere Discuss., doi:10.5194/tc-2016-180,2016 Manuscript under review for TC (discussion: open, 0 comments) In this paper we investigate elevation changes of Thwaites Glacier, West Antarctica, one of the main sources of excess ice discharge into the ocean. We find that in early 2013, four subglacial lakes separated by 100 km drained suddenly, discharging more than three cubic kilometers of water under the fastest part of the glacier in less than six months. Concurrent ice-speed measurements show only minor changes, suggesting that ice dynamics are not strongly sensitive to changes in water flow.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 22
    facet.materialart.
    Unknown
    Isotopic exchange on the diurnal scale between near-surface snow and lower atmospheric water vapor at Kohnen station, East Antarctica (2016)
    Copernicus
    Details
    Publication Date: 2016-07-30
    Description: Isotopic exchange on the diurnal scale between near-surface snow and lower atmospheric water vapor at Kohnen station, East Antarctica François Ritter, Hans Christian Steen-Larsen, Martin Werner, Valérie Masson-Delmotte, Anais Orsi, Melanie Behrens, Gerit Birnbaum, Johannes Freitag, Camille Risi, and Sepp Kipfstuhl The Cryosphere, 10, 1647-1663, doi:10.5194/tc-10-1647-2016, 2016 We present the first successful continuous measurements of water vapor isotopes performed in Antarctica in January 2013. The interest is to understand the impact of the water vapor isotopic composition on the near-surface snow isotopes. Our study reveals a diurnal cycle in the snow isotopic composition in phase with the vapor. This finding suggests fractionation during the sublimation of the ice, which has an important consequence on the interpretation of water isotope variations in ice cores.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 23
    facet.materialart.
    Unknown
    An automated methodology for differentiating rock from snow, clouds and sea in Antarctica from Landsat 8 imagery: a new rock outcrop map and area estimation for the entire Antarctic continent (2016)
    Copernicus
    Details
    Publication Date: 2016-08-02
    Description: An automated methodology for differentiating rock from snow, clouds and sea in Antarctica from Landsat 8 imagery: a new rock outcrop map and area estimation for the entire Antarctic continent Alex Burton-Johnson, Martin Black, Peter T. Fretwell, and Joseph Kaluza-Gilbert The Cryosphere, 10, 1665-1677, doi:10.5194/tc-10-1665-2016, 2016 We present a new rock outcrop map for the entire Antarctic continent, a principal base dataset for research and mapping in Antarctica with broad applications. To derive the map, a new methodology was developed and applied to allow automated identification of rock outcrops from Landsat 8 satellite images whilst excluding sunlit and shaded snow, clouds and liquid water – the first such automated methodology. The new dataset reveals that exposed rock forms only 0.18 % of the entire continent.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 24
    facet.materialart.
    Unknown
    Evaposublimation from the snow in the Mediterranean mountains of Sierra Nevada (Spain) (2016)
    Copernicus
    Details
    Publication Date: 2016-08-02
    Description: Evaposublimation from the snow in the Mediterranean mountains of Sierra Nevada (Spain) Javier Herrero and María José Polo The Cryosphere Discuss., doi:10.5194/tc-2016-161,2016 Manuscript under review for TC (discussion: open, 0 comments) This manuscript presents 7 years of field work and modelling to assess the importance of the loss of water from the snow by means of sublimation in the Mediterranean mountains of Sierra Nevada. The actual sublimation rates were detected through detailed measurement of the mass fluxes from the snow. These data have led to some improvements in the modelling of the snow in this kind of mountainous semiarid regions. The sublimation is estimated to range between 24–33 % of total annual snowfall.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 25
    facet.materialart.
    Unknown
    Signature of Arctic first-year ice melt pond fraction in X-band SAR imagery (2016)
    Copernicus
    Details
    Publication Date: 2016-08-02
    Description: Signature of Arctic first-year ice melt pond fraction in X-band SAR imagery Ane S. Fors, Dmitry V. Divine, Anthony P. Doulgeris, Angelika H. H. Renner, and Sebastian Gerland The Cryosphere Discuss., doi:10.5194/tc-2016-125,2016 Manuscript under review for TC (discussion: open, 0 comments) This paper investigates the signature of melt ponds in satellite borne synthetic aperture radar (SAR) imagery. The study shows that polarimetric X-band SAR can be used to extract melt pond fraction from drifting first-year sea ice, and discusses the influence of factors like wind speed, SAR incidence angle and instrument noise floor. Melt ponds strongly influence the Arctic sea ice energy budget, and the results imply prospective opportunities for expanded monitoring of melt ponds from space.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 26
    facet.materialart.
    Unknown
    Diagnosing the decline in climatic mass balance of glaciers in Svalbard over 1957–2014 (2016)
    Copernicus
    Details
    Publication Date: 2016-08-02
    Description: Diagnosing the decline in climatic mass balance of glaciers in Svalbard over 1957–2014 Torbjørn Ims Østby, Thomas Vikhamar Schuler, Jon Ove Hagen, Regine Hock, Jack Kohler, and Carleen H. Reijmer The Cryosphere Discuss., doi:10.5194/tc-2016-172,2016 Manuscript under review for TC (discussion: open, 0 comments) We present modeled climatic mass balance for all glaciers in Svalbard for the period 1957–2014 at 1 km resolution using a coupled surface energy balance and snowpack model, thereby closing temporal and spatial gaps in direct and geodetic mass balance estimates. Supporting previous studies, our results indicate increased mass loss over the period. A detailed analysis of the involved energy fluxes reveals that increased mass loss is caused by atmospheric warming further amplified by feedbacks.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 27
    facet.materialart.
    Unknown
    Simulating ice layer formation under the presence of preferential flow in layered snowpacks (2016)
    Copernicus
    Details
    Publication Date: 2016-08-04
    Description: Simulating ice layer formation under the presence of preferential flow in layered snowpacks Nander Wever, Sebastian Würzer, Charles Fierz, and Michael Lehning The Cryosphere Discuss., doi:10.5194/tc-2016-185,2016 Manuscript under review for TC (discussion: open, 0 comments) The study presents a dual domain approach to simulate liquid water flow in snow using the 1-dimensional physics based snow cover model SNOWPACK. In this approach, the pore space is separated into a part for matrix flow and a part that represents preferential flow. Using this approach, water can percolate sub-freezing snow and form dense (ice) layers. A comparison with snow pits shows that some of the observed ice layers were reproduced by the model while others remain challenging to simulate.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 28
    facet.materialart.
    Unknown
    Marine ice sheet model performance depends on basal sliding physics and sub-shelf melting (2016)
    Copernicus
    Details
    Publication Date: 2016-07-07
    Description: Marine ice sheet model performance depends on basal sliding physics and sub-shelf melting Rupert Michael Gladstone, Roland Charles Warner, Benjamin Keith Galton-Fenzi, Olivier Gagliardini, Thomas Zwinger, and Ralf Greve The Cryosphere Discuss., doi:10.5194/tc-2016-149,2016 Manuscript under review for TC (discussion: open, 0 comments) Computer models are used to simulate the behaviour of glaciers and ice sheets. It has been found that such models are required to be run at very high resolution (which means high computational expense) in order to accurately represent the evolution of marine ice sheets (ice sheets resting on bedrock below sea level), in certain situations.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 29
    facet.materialart.
    Unknown
    Effects of Seasonal Snow Cover on Hydrothermal Conditions of the Active Layer in the Northeastern Qinghai-Tibet Plateau (2016)
    Copernicus
    Details
    Publication Date: 2016-07-07
    Description: Effects of Seasonal Snow Cover on Hydrothermal Conditions of the Active Layer in the Northeastern Qinghai-Tibet Plateau Ji Chen, Yu Sheng, Qingbai Wu, Lin Zhao, Jing Li, and Jingyi Zhao The Cryosphere Discuss., doi:10.5194/tc-2016-134,2016 Manuscript under review for TC (discussion: open, 0 comments) The extreme thin and short-time snow cover in the northeastern Qinghai-Tibet plateau is predominantly during spring and autumn. Removal of seasonal snow cover is beneficial for cooling the active layer in the first few years. Seasonal snow cover maintains the high water content of the active layer because of the inhibitory action of snow cover on the evaporation capacity in the natural site during the daytime and in summer. Snow removal can therefore lead to a rapid decrease of soil moisture.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 30
    facet.materialart.
    Unknown
    Surface mass balance and water stable isotopes derived from firn cores on three ice rises, Fimbul Ice Shelf, Antarctica (2016)
    Copernicus
    Details
    Publication Date: 2016-07-07
    Description: Surface mass balance and water stable isotopes derived from firn cores on three ice rises, Fimbul Ice Shelf, Antarctica Carmen P. Vega, Elisabeth Schlosser, Dmitry V. Divine, Jack Kohler, Tõnu Martma, Anja Eichler, Margit Schwikowski, and Elisabeth Isaksson The Cryosphere Discuss., doi:10.5194/tc-2016-164,2016 Manuscript under review for TC (discussion: open, 0 comments) Surface mass balance and water stable isotopes from firn cores on three ice rises at Fimbul Ice Shelf, are reported. The results suggest that the ice rises are suitable sites for the retrieval of longer firn and ice cores. The first deuterium excess data for the area suggests a possible role of seasonal moisture transport changes on the annual isotopic signal. Large-scale atmospheric circulation patterns most likely provide the dominant influence on water stable isotope ratios at the sites.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 31
    facet.materialart.
    Unknown
    Reflective properties of white and snow-covered sea ice (2016)
    Copernicus
    Details
    Publication Date: 2016-07-08
    Description: Reflective properties of white and snow-covered sea ice Aleksey Malinka, Eleonora Zege, Georg Heygster, and Larysa Istomina The Cryosphere Discuss., doi:10.5194/tc-2016-153,2016 Manuscript under review for TC (discussion: open, 0 comments) The amount of melt ponds on Arctic summer sea ice and its reflectance are required for better climate modelling and weather prediction. In order to derive these quantities from optical satellite observations, simple analytical formulas for the bidirectional reflectance factor and albedo at direct and diffuse incidence are derived from basic assumptions and verified with in situ measurements made during the expedition ARK-XXVII/3 of research vessel Polarstern in 2012.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 32
    facet.materialart.
    Unknown
    Basin-wide N2 fixation in the deep waters of the Mediterranean Sea (2016)
    Wiley
    Details
    Publication Date: 2016-06-21
    Description: Recent findings indicate that N 2 fixation is significant in aphotic waters, presumably due to heterotrophic diazotrophs depending on organic matter for their nutrition. However, the relationship between organic matter and heterotrophic N 2 fixation remains unknown. Here we explore N 2 fixation in the deep chlorophyll maximum (DCM) and underneath deep waters across the whole Mediterranean Sea and relate it to organic matter composition, characterized by optical and molecular methods. Our N 2 fixation rates were in the range of those previously reported for the euphotic zone of the Mediterranean Sea (up to 0.43 nmol N L -1 d -1 ), and were significantly correlated to the presence of relatively labile organic matter with fluorescence and molecular formula properties representative for peptides and unsaturated aliphatics, and associated with the presence of more oxygenated ventilated water masses. Finally, and despite aphotic N 2 fixation contributes largely to total water column diazotrophic activity (〉50%), its contribution to overall nitrogen inputs to the basin is negligible (〈0.5%).
    Print ISSN: 0886-6236
    Electronic ISSN: 1944-9224
    Topics: Biology , Chemistry and Pharmacology , Geography , Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 33
    facet.materialart.
    Unknown
    Enzyme-level Interconversion of Nitrate and Nitrite in the Fall Mixed Layer of the Antarctic Ocean (2016)
    Wiley
    Details
    Publication Date: 2016-06-21
    Description: In the Southern Ocean, the nitrogen (N) isotopes of organic matter and the N and oxygen (O) isotopes of nitrate (NO 3 - ) have been used to investigate NO 3 - assimilation and N cycling in the summertime period of phytoplankton growth, both today and in the past. However, recent studies indicate the significance of processes in other seasons for producing the annual cycle of N isotope changes. This study explores the impact of fall conditions on the 15 N/ 14 N (δ 15 N) and 18 O/ 16 O (δ 18 O) of NO 3 - and nitrite (NO 2 - ) in the Pacific Antarctic Zone using depth profiles from late summer/fall of 2014. In the mixed layer, the δ 15 N and δ 18 O of NO 3 -  + NO 2 - increase roughly equally, as expected for NO 3 - assimilation; however, the δ 15 N of NO 3 - -only (measured after NO 2 - removal) increases more than NO 3 - -only δ 18 O. Differencing indicates that NO 2 - has an extremely low δ 15 N, often 〈 -70‰ vs. air. These observations are consistent with the expression of an equilibrium N isotope effect between NO 3 - and NO 2 - , likely due to enzymatic NO 3 - -NO 2 - interconversion. Specifically, we propose reversibility of the nitrite oxidoreductase (NXR) enzyme of nitrite oxidizers that, having been entrained from the subsurface during late summer mixed layer deepening, are inhibited by light. Our interpretation suggests a role for NO 3 - -NO 2 - interconversion where nitrifiers are transported into environments that discourage NO 2 - oxidation. This may apply to surface regions with upwelling, such as the summertime Antarctic. It may also apply to oxygen-deficient zones, where NXR-catalyzed interconversion may explain previously-reported evidence of NO 2 - oxidation.
    Print ISSN: 0886-6236
    Electronic ISSN: 1944-9224
    Topics: Biology , Chemistry and Pharmacology , Geography , Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 34
    facet.materialart.
    Unknown
    Application and validation of long-range terrestrial laser scanning to monitor the mass balance of very small glaciers in the Swiss Alps (2016)
    Copernicus
    Details
    Publication Date: 2016-06-21
    Description: Application and validation of long-range terrestrial laser scanning to monitor the mass balance of very small glaciers in the Swiss Alps Mauro Fischer, Matthias Huss, Mario Kummert, and Martin Hoelzle The Cryosphere, 10, 1279-1295, doi:10.5194/tc-10-1279-2016, 2016 This study provides the first thorough validation of geodetic glacier mass changes derived from close-range high-resolution remote sensing techniques, and highlights the potential of terrestrial laser scanning for repeated mass balance monitoring of very small alpine glaciers. The presented methodology is promising, as laborious and potentially dangerous in situ measurements as well as the spatial inter- and extrapolation of point measurements over the entire glacier can be circumvented.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 35
    facet.materialart.
    Unknown
    Greenland Ice Sheet seasonal and spatial mass variability from model simulations and GRACE (2003–2012) (2016)
    Copernicus
    Details
    Publication Date: 2016-06-21
    Description: Greenland Ice Sheet seasonal and spatial mass variability from model simulations and GRACE (2003–2012) Patrick M. Alexander, Marco Tedesco, Nicole-Jeanne Schlegel, Scott B. Luthcke, Xavier Fettweis, and Eric Larour The Cryosphere, 10, 1259-1277, doi:10.5194/tc-10-1259-2016, 2016 We compared satellite-derived estimates of spatial and seasonal variations in Greenland Ice Sheet mass with a set of model simulations, revealing an agreement between models and satellite estimates for the ice-sheet-wide seasonal fluctuations in mass, but disagreement at finer spatial scales. The model simulations underestimate low-elevation mass loss. Improving the ability of models to capture variations and trends in Greenland Ice Sheet mass is important for estimating future sea level rise.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 36
    facet.materialart.
    Unknown
    Development and calibration of an automatic spectral albedometer to estimate near-surface snow SSA time series (2016)
    Copernicus
    Details
    Publication Date: 2016-06-22
    Description: Development and calibration of an automatic spectral albedometer to estimate near-surface snow SSA time series Ghislain Picard, Quentin Libois, Laurent Arnaud, Gauthier Verin, and Marie Dumont The Cryosphere, 10, 1297-1316, doi:10.5194/tc-10-1297-2016, 2016 Albedo of snow surfaces depends on snow grain size. By measuring albedo during 3 years at Dome C in Antarctica with an automatic spectroradiometer, we were able to monitor the snow specific surface area and show an overall growth of the grains in spring and summer followed by an accumulation of small-grained snow from mid-summer. This study focuses on the uncertainties due to the spectroradiometer and concludes that the observed variations are significant with respect to the precision.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 37
    facet.materialart.
    Unknown
    Which are the highest peaks in the US Arctic? Fodar settles the debate (2016)
    Copernicus
    Details
    Publication Date: 2016-06-24
    Description: Which are the highest peaks in the US Arctic? Fodar settles the debate Matt Nolan and Kit DesLauriers The Cryosphere, 10, 1245-1257, doi:10.5194/tc-10-1245-2016, 2016 We measured the heights of the five tallest peaks in the US Arctic using fodar, a new airborne photogrammetric technique using structure-from-motion software. The highest peaks are Mt Isto (2735.6 m), Mt. Hubley (2717.6 m), Mt. Chamberlin (2712.3 m), Mt. Michelson (2698.1 m), and an unnamed peak (2694.9 m). We found fodar suitable for topographic change detection on the centimeter scale in steep mountain terrain, such as for measuring snow depths.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 38
    facet.materialart.
    Unknown
    Three-year monitoring of stable isotopes of precipitation at Concordia Station, East Antarctica (2016)
    Copernicus
    Details
    Publication Date: 2016-06-21
    Description: Three-year monitoring of stable isotopes of precipitation at Concordia Station, East Antarctica Barbara Stenni, Claudio Scarchilli, Valerie Masson-Delmotte, Elisabeth Schlosser, Virginia Ciardini, Giuliano Dreossi, Paolo Grigioni, Mattia Bonazza, Anselmo Cagnati, Daniele Karlicek, Camille Risi, Roberto Udisti, and Mauro Valt The Cryosphere Discuss., doi:10.5194/tc-2016-142,2016 Manuscript under review for TC (discussion: open, 0 comments) Here, we focus on the Concordia Station, central East Antarctic plateau, providing a multi-year record (2008–2010) of daily precipitation types identified from crystal morphologies, precipitation amounts, and isotopic composition. Relationships between local meteorological data and precipitation oxygen isotope composition are investigated. Our dataset is available for in depth model evaluation at the synoptic scale.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 39
    facet.materialart.
    Unknown
    Development and analysis of a continuous record of global near-surface soil freeze/thaw patterns from AMSR-E and AMSR2 data (2016)
    Copernicus
    Details
    Publication Date: 2016-06-22
    Description: Development and analysis of a continuous record of global near-surface soil freeze/thaw patterns from AMSR-E and AMSR2 data Tongxi Hu, Tianjie Zhao, Jiancheng Shi, Tianxing Wang, Dabin Ji, Ahmad Al Bitar, Bin Peng, and Yurong Cui The Cryosphere Discuss., doi:10.5194/tc-2016-115,2016 Manuscript under review for TC (discussion: open, 0 comments) We present an approach of satellite remote sensing to derive a continuous long term and stable data record of the near-surface freeze/thaw cycle over the permafrost and seasonally frozen ground. We find that the distribution of the frost days and its trend variations are consistent with the minimum temperature anomalies. Analysis over the Qinghai-Tibetan Plateau demonstrates that the frost period is shortening slightly over the past decade, and the last frost date is advanced in most regions.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 40
    facet.materialart.
    Unknown
    Operational algorithm for ice/water classification on dual-polarized RADARSAT-2 images (2016)
    Copernicus
    Details
    Publication Date: 2016-06-22
    Description: Operational algorithm for ice/water classification on dual-polarized RADARSAT-2 images Natalia Zakhvatkina, Anton Korosov, Stefan Muckenhuber, Stein Sandven, and Mohamed Babiker The Cryosphere Discuss., doi:10.5194/tc-2016-131,2016 Manuscript under review for TC (discussion: open, 0 comments) The presented fully automated algorithm distinguishes open water (rough/calm) and sea ice based on dual-polarized RS2 SAR images. Texture features are used for Support Vector Machines supervised image classification. The algorithm includes pre-processing and validation procedures. More than 2700 scenes were processed and the results show the good discrimination between open water and sea ice areas with accuracy 91 % compared with ice charts produced by MET Norway service.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 41
    facet.materialart.
    Unknown
    Imaging air volume fraction in sea ice using non-destructive X-ray tomography (2016)
    Copernicus
    Details
    Publication Date: 2016-05-28
    Description: Imaging air volume fraction in sea ice using non-destructive X-ray tomography Odile Crabeck, Ryan Galley, Bruno Delille, Brent Else, Nicolas-Xavier Geilfus, Marcos Lemes, Mathieu Des Roches, Pierre Francus, Jean-Louis Tison, and Søren Rysgaard The Cryosphere, 10, 1125-1145, doi:10.5194/tc-10-1125-2016, 2016 We present a new non-destructive X-ray-computed tomography technique to quantify the air volume fraction and produce separate 3-D images of air-volume inclusions in sea ice. While the internal layers showed air-volume fractions 〈 2 %, the ice–air interface (top 2 cm) showed values up to 5 %. As a result of the presence of large bubbles and higher air volume fraction measurements in sea ice, we introduce new perspectives on processes regulating gas exchange at the ice–atmosphere interface.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 42
    facet.materialart.
    Unknown
    Monitoring the temperature dependent elastic and anelastic properties in isotropic polycrystalline ice using resonant ultrasound spectroscopy (2016)
    Copernicus
    Details
    Publication Date: 2016-05-28
    Description: Monitoring the temperature dependent elastic and anelastic properties in isotropic polycrystalline ice using resonant ultrasound spectroscopy Matthew J. Vaughan, Kasper van Wilk, David J. Prior, and M. Hamish Bowman The Cryosphere Discuss., doi:10.5194/tc-2016-127,2016 Manuscript under review for TC (discussion: open, 0 comments) The physical properties of ice are of interest in the study of the dynamics of sea ice, glaciers and ice sheets. We used resonant ultrasound spectroscopy to estimate the effects of temperature on the elastic and an-elastic characteristics of polycrystalline ice, which control the propagation of sound waves. This information helps calibrate seismic data, in order to determine regional scale ice properties, improving our ability to predict ice sheet behaviour in response to climate change.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 43
    facet.materialart.
    Unknown
    Basal buoyancy and fast-moving glaciers: in defense of analytic force balance (2016)
    Copernicus
    Details
    Publication Date: 2016-06-30
    Description: Basal buoyancy and fast-moving glaciers: in defense of analytic force balance C. J. van der Veen The Cryosphere, 10, 1331-1337, doi:10.5194/tc-10-1331-2016, 2016 This paper evaluates the geometric force balance, with application to Byrd Glacier, Antarctica. It is concluded that this approach does not yield physically reasonable results.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 44
    facet.materialart.
    Unknown
    Satellite estimates of net community production based on O2/Ar observations and comparison to other estimates. (2016)
    Wiley
    Details
    Publication Date: 2016-05-09
    Description: We present two statistical algorithms for predicting global oceanic net community production (NCP) from satellite observations. To calibrate these two algorithms, we compiled a large dataset of in situ O 2 /Ar-NCP and remotely sensed observations, including sea surface temperature (SST), net primary production (NPP), phytoplankton size composition, and inherent optical properties. The first algorithm is based on genetic programming (GP) which simultaneously searches for the optimal form and coefficients of NCP equations. We find that several GP solutions are consistent with NPP and SST being strong predictors of NCP. The second algorithm uses support vector regression (SVR) to optimize a numerical relationship between O 2 /Ar-NCP measurements and satellite observations. Both statistical algorithms can predict NCP relatively well, with a coefficient of determination ( R 2 ) of 0.68 for GP and 0.72 for SVR, which is comparable to other algorithms in the literature. However, our new algorithms predict more spatially uniform annual NCP distribution for the world's oceans and higher annual NCP values in the Southern Ocean and the five oligotrophic gyres.
    Print ISSN: 0886-6236
    Electronic ISSN: 1944-9224
    Topics: Biology , Chemistry and Pharmacology , Geography , Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 45
    facet.materialart.
    Unknown
    Amazon forest response to repeated droughts (2016)
    T.R. Feldpausch, O.L. Phillips, R.J.W. Brienen, E. Gloor, J. Lloyd, G. Lopez-Gonzalez, A. Monteagudo-Mendoza, Y. Malhi, A. Alarcón, E. Álvarez Dávila, P. Alvarez-Loayza, A. Andrade, L.E.O.C. Aragao, L. Arroyo, G.A. Aymard C., T.R. Baker, C. Baraloto, J. Barroso, D. Bonal, W. Castro, V. Chama, J. Chave, T.F. Domingues, S. Fauset, N. Groot, E. Honorio C., S. Laurance, W.F. Laurance, S.L. Lewis, J.C. Licona, B.S. Marimon, B.H. Marimon-Junior, C. Mendoza Bautista, D.A. Neill, E.A. Oliveira, C. Oliveira dos Santos, N.C. Pallqui Camacho, G. Pardo-Molina, A. Prieto, C.A. Quesada, F. Ramírez, H. Ramírez-Angulo, M. Réjou-Méchain, A. Rudas, G. Saiz, R.P. Salomão, J.E. Silva-Espejo, M. Silveira, H. Steege, J. Stropp, J. Terborgh, R. Thomas-Caesar, G.M.F. Heijden, R. Vásquez Martinez, E. Vilanova, V.A. Vos
    Wiley
    Details
    Publication Date: 2016-05-01
    Description: The Amazon Basin has experienced more variable climate over the last decade, with a severe and widespread drought in 2005 causing large basin-wide losses of biomass. A drought of similar climatological magnitude occurred again in 2010; however, there has been no basin-wide ground-based evaluation of effects on vegetation. We examine to what extent the 2010 drought affected forest dynamics using ground-based observations of mortality and growth utilizing data from an extensive forest plot network. We find that during the 2010 drought interval, forests did not gain biomass (net change: −0.43 Mg ha -1 , CI: −1.11, 0.19, n = 97), regardless of whether forests experienced precipitation deficit anomalies. This loss contrasted with a long-term biomass sink during the baseline pre-2010 drought period (1998 − pre-2010) of 1.33 Mg ha -1 yr -1 (CI: 0.90, 1.74, p  〈 0.01). The resulting net impact of the 2010 drought (i.e., reversal of the baseline net sink) was −1.95 Mg ha -1 yr -1 (CI:−2.77, −1.18; p  〈 0.001). This net biomass impact was driven by an increase in biomass mortality (1.45 Mg ha -1 yr -1 CI: 0.66, 2.25, p  〈 0.001), and a decline in biomass productivity (−0.50 Mg ha -1 yr -1 , CI:−0.78, −0.31; p  〈 0.001). Surprisingly, the magnitude of the losses through tree mortality was unrelated to estimated local precipitation anomalies, and was independent of estimated local pre-2010 drought history. Thus, there was no evidence that pre-2010 droughts compounded the effects of the 2010 drought. We detected a systematic basin-wide impact of drought on tree growth rates across Amazonia, with this suppression of productivity driven by moisture deficits in 2010, an impact which was not apparent during the 2005 event [ Phillips et al. , 2009]. Based on these ground data, both live biomass in trees and corresponding estimates of live biomass in roots, we estimate that intact forests in Amazonia were carbon neutral in 2010 (−0.07 PgC yr -1 CI:−0.42, 0.23), consistent with results from an independent analysis of airborne estimates of land-atmospheric fluxes during 2010 [ Gatti et al. , 2014]. Relative to the long-term mean, the 2010 drought resulted in a reduction in biomass carbon uptake of 1.1 PgC, compared to 1.6 PgC for the 2005 event [ Phillips et al . 2009].
    Print ISSN: 0886-6236
    Electronic ISSN: 1944-9224
    Topics: Biology , Chemistry and Pharmacology , Geography , Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 46
    facet.materialart.
    Unknown
    Assessment of Arctic and Antarctic Sea Ice Predictability in CMIP5 Decadal Hindcasts (2016)
    Copernicus
    Details
    Publication Date: 2016-05-11
    Description: Assessment of Arctic and Antarctic Sea Ice Predictability in CMIP5 Decadal Hindcasts Chao-Yuan Yang, Jiping Liu, Yongyun Hu, Radley M. Horton, Liqi Chen, and Xiao Cheng The Cryosphere Discuss., doi:10.5194/tc-2016-97,2016 Manuscript under review for TC (discussion: open, 0 comments) This paper examines the ability of coupled global climate models to predict decadal variability of Arctic and Antarctic sea ice. We analyze decadal hindcasts/predictions of 11 CMIP5 models. Decadal hindcasts exhibit a large multi-model spread in the simulated sea ice extent, with some models deviating significantly from the observations. For the models having large biases and using full-field initialization, the predicted sea ice extent quickly drifts away from the initial constraint, deteriorating the decadal predictive skill. The anomaly correlation analysis between the decadal hindcast and observed sea ice suggests that in the Arctic, for most models, the areas showing significant predictive skill become broader associated with increasing lead times. This area expansion is largely because nearly all the models are capable of predicting the observed decreasing Arctic sea ice cover. Sea ice extent in the north Pacific has better predictive skill than that in the north Atlantic (particularly at a lead-time of 3–7 years), but there is a re-emerging predictive skill in the north Atlantic at a lead-time of 6–8 years. In contrast to the Arctic, Antarctic sea ice decadal hindcasts do not show broad predictive skill at any time scales, and there is no obvious improvement linking the areal extent of significant predictive skill to lead-time increase. This might be because nearly all the models predict a retreating Antarctic sea ice cover, opposite to the observations. For the Arctic, the predictive skill of the MMEE outperforms most models and the persistence prediction at longer time scales, which is not the case for the Antarctic.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 47
    facet.materialart.
    Unknown
    On the recent contribution of the Greenland ice sheet to sea level change (2016)
    Copernicus
    Details
    Publication Date: 2016-05-27
    Description: On the recent contribution of the Greenland ice sheet to sea level change Michiel van den Broeke, Ellyn Enderlin, Ian Howat, Peter Kuipers Munneke, Brice Noël, Willem Jan van de Berg, Erik van Meijgaard, and Bert Wouters The Cryosphere Discuss., doi:10.5194/tc-2016-123,2016 Manuscript under review for TC (discussion: open, 0 comments) We present recent (1958–2015) mass balance time series for the Greenland ice sheet. We show that recent mass loss is caused by a combination of increased surface meltwater runoff and solid ice discharge. Most meltwater above 2000 m a.s.l. refreezes in the cold firn and does not leave the ice sheet, but this goes at the expense of firn heating and densifying. In spite of a temporary rebound in 2013, it appears that the ice sheet remains in a state of persistent mass loss
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 48
    facet.materialart.
    Unknown
    Reconstructing the mass balance of Brewster Glacier, New Zealand, using MODIS-derived glacier-wide albedo (2016)
    Copernicus
    Details
    Publication Date: 2016-05-27
    Description: Reconstructing the mass balance of Brewster Glacier, New Zealand, using MODIS-derived glacier-wide albedo Pascal Sirguey, Holly Still, Nicolas J. Cullen, Marie Dumont, Yves Arnaud, and Jonathan P. Conway The Cryosphere Discuss., doi:10.5194/tc-2016-98,2016 Manuscript under review for TC (discussion: open, 0 comments) 14 years of satellite observations are used to monitor the albedo of Brewster Glacier, New Zealand and estimate annual and seasonal balances. This confirms the governing role of the summer balance in the annual balance and allows the reconstruction of the annual balance back to 1977 using a photographic record of the snowline. The longest mass balance record for a New Zealand glacier shows that negative balances after 2008 yielded a loss of 35 % of the gain accumulated over the previous 30 years.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 49
    facet.materialart.
    Unknown
    Modeling debris-covered glaciers: response to steady debris deposition (2016)
    Copernicus
    Details
    Publication Date: 2016-05-27
    Description: Modeling debris-covered glaciers: response to steady debris deposition Leif S. Anderson and Robert S. Anderson The Cryosphere, 10, 1105-1124, doi:10.5194/tc-10-1105-2016, 2016 Mountains erode and shed rocks down slope. When these rocks (debris) fall on glacier ice they can suppress ice melt. By protecting glaciers from melt, debris can make glaciers extend to lower elevations. Using mathematical models of glaciers and debris deposition, we find that debris can more than double the length of glaciers. The amount of debris deposited on the glacier, which scales with mountain height and steepness, is the most important control on debris-covered glacier length and volume.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 50
    facet.materialart.
    Unknown
    Improving satellite-retrieved surface radiative fluxes in polar regions using a smart sampling approach (2016)
    Copernicus
    Details
    Publication Date: 2016-05-27
    Description: Improving satellite-retrieved surface radiative fluxes in polar regions using a smart sampling approach Kristof Van Tricht, Stef Lhermitte, Irina V. Gorodetskaya, and Nicole P. M. van Lipzig The Cryosphere Discuss., doi:10.5194/tc-2016-103,2016 Manuscript under review for TC (discussion: open, 0 comments) Despite the crucial role of polar regions in the global climate system, the limited availability of observations on the ground hampers a detailed understanding of their energy budget. Here we develop a method to use satellites to fill these observational gaps. We show that by sampling satellite observations in a smart way, coverage is greatly enhanced. We conclude that this method might help improving our understanding of the polar energy budget, and ultimately its effects in the global climate.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 51
    facet.materialart.
    Unknown
    Impacts of marine instability across the East Antarctic Ice Sheet on Southern Ocean dynamics (2016)
    Copernicus
    Details
    Publication Date: 2016-05-27
    Description: Impacts of marine instability across the East Antarctic Ice Sheet on Southern Ocean dynamics Steven J. Phipps, Christopher J. Fogwill, and Christian S. M. Turney The Cryosphere Discuss., doi:10.5194/tc-2016-111,2016 Manuscript under review for TC (discussion: open, 0 comments) We explore the effects of melting of the East Antarctic Ice Sheet on the Southern Ocean. Using a climate model, we find that melting changes the ocean circulation and causes warming of more than 1 ºC at depth. We also discover the potential existence of a "domino effect", whereby the initial warming spreads westwards around the Antarctic continent. Melting of just one sector could therefore destabilise the wider Antarctic Ice Sheet, leading to substantial increases in global sea level.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 52
    facet.materialart.
    Unknown
    The Influence of Southern Ocean Winds on the North Atlantic Carbon Sink (2016)
    Wiley
    Details
    Publication Date: 2016-05-13
    Description: Observed and predicted increases in Southern Ocean winds are thought to upwell deep ocean carbon and increase atmospheric CO 2 . However, Southern Ocean dynamics affect biogeochemistry and circulation pathways on a global scale. Using idealised MITgcm simulations, we demonstrate that an increase in Southern Ocean winds reduces the carbon sink in the North Atlantic sub-polar gyre. The increase in atmospheric CO 2 due to the reduction of the North Atlantic carbon sink is shown to be of the same magnitude as the increase in atmospheric CO 2 due to Southern Ocean outgassing. The mechanism can be described as follows: The increase in Southern Ocean winds leads to an increase in upper ocean northward nutrient transport. Biological productivity is therefore enhanced in the tropics, which alters the chemistry of the sub-thermocline waters that are ultimately upwelled in the subpolar gyre. The results demonstrate the influence of Southern Ocean winds on the North Atlantic carbon sink and show that the effect of Southern Ocean winds on atmospheric CO 2 is likely twice as large as previously thought in past, present, and future climates.
    Print ISSN: 0886-6236
    Electronic ISSN: 1944-9224
    Topics: Biology , Chemistry and Pharmacology , Geography , Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 53
    facet.materialart.
    Unknown
    Mechanism of Seasonal Arctic Sea Ice Evolution and Arctic Amplification (2016)
    Copernicus
    Details
    Publication Date: 2016-04-30
    Description: Mechanism of Seasonal Arctic Sea Ice Evolution and Arctic Amplification Kwang-Yul Kim, Benjamin D. Hamlington, Hanna Na, and Jinju Kim The Cryosphere Discuss., doi:10.5194/tc-2016-69,2016 Manuscript under review for TC (discussion: open, 0 comments) Analysis reveals that "Arctic Amplification", lower tropospheric winter temperature rise in the Arctic, is due to sea ice melting and the resulting increase in the amount of turbulent heat flux from the ocean. As a result of increased turbulent heat flux, lower atmosphere warms up, resulting in increased downward longwave radiation. A detailed physical mechanism is presented together with an explanation why this positive feedback process is currently possible in the Barents-Kara Seas.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 54
    facet.materialart.
    Unknown
    Glacier melting and precipitation trends detected by surface area changes in Himalayan ponds (2016)
    Copernicus
    Details
    Publication Date: 2016-03-23
    Description: Glacier melting and precipitation trends detected by surface area changes in Himalayan ponds Franco Salerno, Sudeep Thakuri, Nicolas Guyennon, Gaetano Viviano, and Gianni Tartari The Cryosphere Discuss., doi:10.5194/tc-2016-39,2016 Manuscript under review for TC (discussion: open, 0 comments) This contribution shows that the surface area variations of unconnected glacial ponds, i.e., ponds not directly connected to glaciers, can be considered suitable proxies for detecting changes in the main hydrological components of the water balance on the south side of Mt. Everest.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 55
    facet.materialart.
    Unknown
    Influence of plankton community structure on the sinking velocity of marine aggregates (2016)
    Wiley
    Details
    Publication Date: 2016-07-10
    Description: About 50 gigatons of carbon are fixed photosynthetically by surface ocean phytoplankton communities every year. Part of this organic matter is reprocessed within the plankton community to form aggregates which eventually sink and export carbon into the deep ocean. The fraction of organic matter leaving the surface ocean is partly dependent on aggregate sinking velocity which accelerates with increasing aggregate size and density where the latter is controlled by ballast load and aggregate porosity. In May 2011, we moored nine 25 m deep mesocosms in a Norwegian fjord to assess on a daily basis how plankton community structure affects material properties and sinking velocities of aggregates (Ø 80 – 400 µm) collected in the mesocosms' sediment traps. We noted that sinking velocity was not necessarily accelerated by opal ballast during diatom blooms which could be due to relatively high porosity of these rather fresh aggregates. Furthermore, estimated aggregate porosity ( P estimated ) decreased as the picoautotroph (0.2-2 µm) fraction of the phytoplankton biomass increased. Thus, picoautotroph-dominated communities may be indicative for food-webs promoting a high degree of aggregate repackaging with potential for accelerated sinking. Blooms of the coccolithophore Emiliania huxleyi revealed that cell concentrations of ~1500 cells/mL accelerate sinking by about 35-40% which we estimate (by one-dimensional modelling) to elevate organic matter transfer efficiency through the mesopelagic from 14 to 24%. Our results indicate that sinking velocities are influenced by the complex interplay between the availability of ballast minerals and aggregate packaging, both of which are controlled by plankton community structure.
    Print ISSN: 0886-6236
    Electronic ISSN: 1944-9224
    Topics: Biology , Chemistry and Pharmacology , Geography , Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 56
    facet.materialart.
    Unknown
    Glacier melting and precipitation trends detected by surface area changes in Himalayan ponds (2016)
    Copernicus
    Details
    Publication Date: 2016-07-12
    Description: Glacier melting and precipitation trends detected by surface area changes in Himalayan ponds Franco Salerno, Sudeep Thakuri, Nicolas Guyennon, Gaetano Viviano, and Gianni Tartari The Cryosphere, 10, 1433-1448, doi:10.5194/tc-10-1433-2016, 2016 This contribution shows that the surface area variations of unconnected glacial ponds, i.e. ponds not directly connected to glacier ice, can be considered as suitable proxies for detecting past changes in the main hydrological components of the water balance (glacier melt, precipitation, evaporation) on the south side of Mt Everest.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 57
    facet.materialart.
    Unknown
    Strain localisation and dynamic recrystallisation in the ice-air aggregate: A numerical study (2016)
    Copernicus
    Details
    Publication Date: 2016-07-12
    Description: Strain localisation and dynamic recrystallisation in the ice-air aggregate: A numerical study Florian Steinbach, Paul D. Bons, Albert Griera, Daniela Jansen, Maria-Gema Llorens, Jens Roessiger, and Ilka Weikusat The Cryosphere Discuss., doi:10.5194/tc-2016-167,2016 Manuscript under review for TC (discussion: open, 0 comments) How glaciers or ice sheets flow is a result of microscopic processes controlled by the properties of individual ice crystals. We performed computer simulations on these processes and the effect of air bubbles between crystals. The simulations show that small scale ice deformation is locally stronger than in other regions, which is enhanced by bubbles. This causes the ice crystals to recrystallise and change their properties in a way that potentially also affects the large scale flow properties.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 58
    facet.materialart.
    Unknown
    Brief Communication: Twelve-year cyclic surging episodes at Donjek Glacier in Yukon, Canada (2016)
    Copernicus
    Details
    Publication Date: 2016-07-12
    Description: Brief Communication: Twelve-year cyclic surging episodes at Donjek Glacier in Yukon, Canada Takahiro Abe, Masato Furuya, and Daiki Sakakibara The Cryosphere, 10, 1427-1432, doi:10.5194/tc-10-1427-2016, 2016 We identified 12-year cyclic surging episodes at Donjek Glacier in Yukon, Canada. The surging area is limited within the ~20km section from the terminus, originating in an area where the flow width significantly narrows downstream. Our results suggest strong control of the valley constriction on the surge dynamics.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 59
    facet.materialart.
    Unknown
    Age of the Mt. Ortles ice cores, the Tyrolean Iceman and glaciation of the highest summit of South Tyrol since the Northern Hemisphere Climatic Optimum (2016)
    Copernicus
    Details
    Publication Date: 2016-07-13
    Description: Age of the Mt. Ortles ice cores, the Tyrolean Iceman and glaciation of the highest summit of South Tyrol since the Northern Hemisphere Climatic Optimum Paolo Gabrielli, Carlo Barbante, Giuliano Bertagna, Michele Bertó, Daniel Binder, Alberto Carton, Luca Carturan, Federico Cazorzi, Giulio Cozzi, Giancarlo Dalla Fontana, Mary Davis, Fabrizio De Blasi, Roberto Dinale, Gianfranco Dragà, Giuliano Dreossi, Daniela Festi, Massimo Frezzotti, Jacopo Gabrieli, Stephan Galos, Patrick Ginot, Petra Heidenwolf, Theo M. Jenk, Natalie Kehrwald, Donald Kenny, Olivier Magand, Volkmar Mair, Vladimir Mikhalenko, Ping Nan Lin, Klaus Oeggl, Gianni Piffer, Mirko Rinaldi, Ulrich Schotterer, Margit Schwikowski, Roberto Seppi, Andrea Spolaor, Barbara Stenni, Davdi Tonidandel, CChiara Uglietti, Victor Zagorodnov, Thomas Zanoner, and Piero Zennaro The Cryosphere Discuss., doi:10.5194/tc-2016-159,2016 Manuscript under review for TC (discussion: open, 0 comments) New ice cores were extracted from Alto dell'Ortles, the highest glacier of South Tyrol in the Italian Alps, to check whether prehistoric ice, that is coeval to the famous 5200 years old Tyrolean Iceman, is still preserved in this region. Dating of the ice cores confirms the hypothesis and indicates that the drilling site was glaciated since the end of the Northern Hemisphere Climatic Optimum (7000 BP). We also infer that an unprecedented acceleration of the glacier flow has just recently begun.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 60
    facet.materialart.
    Unknown
    Coastal dynamics and submarine permafrost in shallow water of the central Laptev Sea, East Siberia (2016)
    Copernicus
    Details
    Publication Date: 2016-07-13
    Description: Coastal dynamics and submarine permafrost in shallow water of the central Laptev Sea, East Siberia Pier Paul Overduin, Sebastian Wetterich, Frank Günther, Mikhail N. Grigoriev, Guido Grosse, Lutz Schirrmeister, Hans-Wolfgang Hubberten, and Aleksandr Makarov The Cryosphere, 10, 1449-1462, doi:10.5194/tc-10-1449-2016, 2016 How fast does permafrost warm up and thaw after it is covered by the sea? Ice-rich permafrost in the Laptev Sea, Siberia, is rapidly eroded by warm air and waves. We used a floating electrical technique to measure the depth of permafrost thaw below the sea, and compared it to 60 years of coastline retreat and permafrost depths from drilling 30 years ago. Thaw is rapid right after flooding of the land and slows over time. The depth of permafrost is related to how fast the coast retreats.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 61
    facet.materialart.
    Unknown
    Issue Information (2016)
    Wiley
    Details
    Publication Date: 2016-07-14
    Description: No abstract is available for this article.
    Print ISSN: 0886-6236
    Electronic ISSN: 1944-9224
    Topics: Biology , Chemistry and Pharmacology , Geography , Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 62
    facet.materialart.
    Unknown
    Inversion of geothermal heat flux in a thermomechanically coupled nonlinear Stokes ice sheet model (2016)
    Copernicus
    Details
    Publication Date: 2016-07-14
    Description: Inversion of geothermal heat flux in a thermomechanically coupled nonlinear Stokes ice sheet model Hongyu Zhu, Noemi Petra, Georg Stadler, Tobin Isaac, Thomas J. R. Hughes, and Omar Ghattas The Cryosphere, 10, 1477-1494, doi:10.5194/tc-10-1477-2016, 2016 We study how well the basal geothermal heat flux can be inferred from surface velocity observations using a thermomechanically coupled nonlinear Stokes ice sheet model. The prospects and limitations of this inversion is studied in two and three dimensional model problems. We also argue that a one-way coupled approach for the adjoint equations motivated by staggered solvers for forward multiphysics problems can lead to an incorrect gradient and premature termination of the optimization iteration.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 63
    facet.materialart.
    Unknown
    Quantifying Mesoscale-Driven Nitrate Supply: A Case Study (2016)
    Wiley
    Details
    Publication Date: 2016-07-15
    Description: The supply of nitrate to surface waters plays a crucial role in maintaining marine life. Physical processes at the mesoscale (~10-100 km) and smaller have been advocated to provide a major fraction of the global supply. Whilst observational studies have focussed on well-defined features, such as isolated eddies, the vertical circulation and nutrient supply in a typical 100-200 km square of ocean will involve a turbulent spectrum of interacting, evolving and decaying features. A crucial step in closing the ocean nitrogen budget is to be able to rank the importance of mesoscale fluxes against other sources of nitrate for surface waters for a representative area of open ocean. While this has been done using models, the vital observational equivalent is still lacking. To illustrate the difficulties that prevent us from putting a global estimate on the significance of the mesoscale observationally, we use data from a cruise in the Iceland Basin where vertical velocity and nitrate observations were made simultaneously at the same high spatial resolution. Local mesoscale nitrate flux is found to be an order of magnitude greater than that due to small-scale vertical mixing and exceeds coincident nitrate uptake rates and estimates of nitrate supply due to winter convection. However, a non-zero net vertical velocity for the region introduces a significant bias in regional estimates of the mesoscale vertical nitrate transport. The need for synopticity means that a more accurate estimate can not be simply found by using a larger survey area. It is argued that time-series, rather than spatial surveys, may be the best means to quantify the contribution of mesoscale processes to the nitrate budget of the surface ocean.
    Print ISSN: 0886-6236
    Electronic ISSN: 1944-9224
    Topics: Biology , Chemistry and Pharmacology , Geography , Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 64
    facet.materialart.
    Unknown
    Slight glacier reduction over the northwestern Tibetan Plateau despite significant recent warming (2016)
    Copernicus
    Details
    Publication Date: 2016-07-15
    Description: Slight glacier reduction over the northwestern Tibetan Plateau despite significant recent warming Yetang Wang, Shugui Hou, Wenling An, Hongxi Pang, and Yaping Liu The Cryosphere Discuss., doi:10.5194/tc-2016-165,2016 Manuscript under review for TC (discussion: open, 0 comments) This study further confirms "Pamir–Karakoram–Western-Kunlun-Mountain (northwestern Tibetan Plateau) Glacier Anomaly". Slight glacier reduction over the northwestern Tibetan Plateau may result from more accumulation from increased precipitation in winter which to great extent protects it from mass reductions under climate warming during 1961–2000. Warming slowdown since 2000 happening at this region may further mitigate glacier mass reduction.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 65
    facet.materialart.
    Unknown
    Characteristics of an avalanche-feeding and partially debris-covered glacier and its response to atmospheric warming in Mt. Tomor, Tian Shan, China (2016)
    Copernicus
    Details
    Publication Date: 2016-07-19
    Description: Characteristics of an avalanche-feeding and partially debris-covered glacier and its response to atmospheric warming in Mt. Tomor, Tian Shan, China Puyu Wang, Zhongqin Li, and Huilin Li The Cryosphere Discuss., doi:10.5194/tc-2016-138,2016 Manuscript under review for TC (discussion: open, 0 comments) A cirque-valley glacier with complex topography and partially debris-covered area was investigated in the Mt. Tomor, Tian Shan. The glacier is analogous to temperate one on movement and temperature regimes. The strongest ablation and most significant terminus retreat and area reduction occurred at the end of last century and the beginning of this century. Since inhibition of debris cover to melting, it is expected to keep shrinkage in the coming decades, but the terminus retreat is to be slower.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 66
    facet.materialart.
    Unknown
    Arctic sea-ice diffusion from observed and simulated Lagrangian trajectories (2016)
    Copernicus
    Details
    Publication Date: 2016-07-20
    Description: Arctic sea-ice diffusion from observed and simulated Lagrangian trajectories Pierre Rampal, Sylvain Bouillon, Jon Bergh, and Einar Ólason The Cryosphere, 10, 1513-1527, doi:10.5194/tc-10-1513-2016, 2016 Due to the increasing activity in Arctic, sea-ice–ocean models are now frequently used to produce operational forecasts, for oil spill trajectory modelling and to assist in offshore operations planning. In this study we evaluate the performance of two models with respect to their capability to reproduce observed sea ice diffusion properties by using metrics based on Lagrangian statistics. This paper presents a new and useful evaluation metric for current coupled sea ice–ocean models.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 67
    facet.materialart.
    Unknown
    Retrieval of the thickness of undeformed sea ice from simulated C-band compact polarimetric SAR images (2016)
    Copernicus
    Details
    Publication Date: 2016-07-20
    Description: Retrieval of the thickness of undeformed sea ice from simulated C-band compact polarimetric SAR images Xi Zhang, Wolfgang Dierking, Jie Zhang, Junmin Meng, and Haitao Lang The Cryosphere, 10, 1529-1545, doi:10.5194/tc-10-1529-2016, 2016 In this work, we introduced a parameter ("CP ratio") for the retrieval of the thickness of undeformed first-year sea ice that is specifically adapted to compact polarimetric SAR images. Based on a validation using other compact polarimetric SAR images from the Labrador Sea, we found a root mean square error of 8 cm and a maximum correlation coefficient of 0.94 for the retrieval procedure when applying it to level ice between 0.1 m and 0.8 m thick.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 68
    facet.materialart.
    Unknown
    High resolution boundary conditions of an old ice target near Dome C, Antarctica (2016)
    Copernicus
    Details
    Publication Date: 2016-07-21
    Description: High resolution boundary conditions of an old ice target near Dome C, Antarctica Duncan A. Young, Jason L. Roberts, Catherine Ritz, Massimo Frezzotti, Enrica Quartini, Marie G. P. Cavitte, Carly R. Tozer, Daniel Steinhage, Stefano Urbini, Hugh F. J. Corr, Tas Van Ommen, and Donald D. Blankenship The Cryosphere Discuss., doi:10.5194/tc-2016-169,2016 Manuscript under review for TC (discussion: open, 0 comments) Glacial ice can preserve records of Earth's ancient atmosphere (including greenhouse gases) that can be compared to ocean sediment records of ice sheet size to better understand climate feedbacks. To find records of the greenhouse gases found in key periods of climate transition, we need to find sites of unmelted old ice near the base of the ice sheet. We performed a high resolution survey of such a site near Europe's Concordia station in East Antarctica, using a multi instrument aircraft.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 69
    facet.materialart.
    Unknown
    Effects of stratified active layers on high-altitude permafrost warming: a case study on the Qinghai–Tibet Plateau (2016)
    Copernicus
    Details
    Publication Date: 2016-07-26
    Description: Effects of stratified active layers on high-altitude permafrost warming: a case study on the Qinghai–Tibet Plateau Xicai Pan, Yanping Li, Qihao Yu, Xiaogang Shi, Daqing Yang, and Kurt Roth The Cryosphere, 10, 1591-1603, doi:10.5194/tc-10-1591-2016, 2016 Using a 9-year dataset in conjunction with a process-based model, we verify that the common assumption of a considerably smaller thermal conductivity in the thawed season than the frozen season is not valid at a site with a stratified active layer on the Qinghai–Tibet Plateau (QTP). The unique hydraulic and thermal mechanism in the active layer challenges the concept of thermal offset used in conceptual permafrost models and hints at the reason for rapid permafrost warming on the QTP.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 70
    facet.materialart.
    Unknown
    Basal sliding of temperate basal ice on a rough, hard bed: pressure melting, creep mechanisms and implications for ice streaming (2016)
    Copernicus
    Details
    Publication Date: 2016-04-02
    Description: Basal sliding of temperate basal ice on a rough, hard bed: pressure melting, creep mechanisms and implications for ice streaming Maarten Krabbendam The Cryosphere Discuss., doi:10.5194/tc-2016-52,2016 Manuscript under review for TC (discussion: open, 0 comments) The way that ice moves over rough ground at the base of an ice sheet is important to understand and predict the behaviour of ice sheets. Here, I argue that if basal ice is at the melting temperature, as is locally the case below the Greenland Ice Sheet, this basal motion is easier and faster than hitherto thought. A thick (10's of metres) layer of ice at the melting temperature may better explain some ice streams, and needs to be taken into account when modelling future ice sheet behaviour.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 71
    facet.materialart.
    Unknown
    Brief communication: Two well-marked cases of aerodynamic adjustment of sastrugi (2016)
    Copernicus
    Details
    Publication Date: 2016-04-02
    Description: Brief communication: Two well-marked cases of aerodynamic adjustment of sastrugi C. Amory, F. Naaim-Bouvet, H. Gallée, and E. Vignon The Cryosphere, 10, 743-750, doi:10.5194/tc-10-743-2016, 2016 This study presents observational characterization of interactions between wind-induced surface roughness and aeolian erosion over a rough surface in coastal East Antarctica. It is shown that the drag caused by small-scale roughness elements can significantly affects the aeolian snow mass flux during an erosion event, depending on the ability of the surface to adjust according to the main wind. Such measurements are essential to improve parameterization schemes for aeolian snow transport models.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 72
    facet.materialart.
    Unknown
    Brief communication: The challenge and benefit of using sea ice concentration satellite data products with uncertainty estimates in summer sea ice data assimilation (2016)
    Copernicus
    Details
    Publication Date: 2016-04-07
    Description: Brief communication: The challenge and benefit of using sea ice concentration satellite data products with uncertainty estimates in summer sea ice data assimilation Qinghua Yang, Martin Losch, Svetlana N. Losa, Thomas Jung, Lars Nerger, and Thomas Lavergne The Cryosphere, 10, 761-774, doi:10.5194/tc-10-761-2016, 2016 We assimilate the summer SICCI sea ice concentration data with an ensemble-based Kalman Filter. Comparing with the approach using a constant data uncertainty, the sea ice concentration estimates are further improved when the SICCI-provided uncertainty are taken into account, but the sea ice thickness cannot be improved. We find the data assimilation system cannot give a reasonable ensemble spread of sea ice concentration and thickness if the provided uncertainty are directly used.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 73
    facet.materialart.
    Unknown
    On retrieving sea ice freeboard from ICESat laser altimeter (2016)
    Copernicus
    Details
    Publication Date: 2016-04-07
    Description: On retrieving sea ice freeboard from ICESat laser altimeter Kirill Khvorostovsky and Pierre Rampal The Cryosphere Discuss., doi:10.5194/tc-2016-50,2016 Manuscript under review for TC (discussion: open, 0 comments) We analyse two methods of freeboard retrieval from ICESat satellite data that were used to derived the two widely used Arctic sea ice thickness products. We show that although different factors results in significant local differences between freeboards, they are roughly compensating each other with respect to overall freeboard estimation. Thus the difference found between the sea ice thickness datasets should be attributed to different parameters used in the freeboard-to-thickness conversion.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 74
    facet.materialart.
    Unknown
    Stable isotopic evidence for high microbial nitrate throughput in a High Arctic glacial catchment (2016)
    Copernicus
    Details
    Publication Date: 2016-04-07
    Description: Stable isotopic evidence for high microbial nitrate throughput in a High Arctic glacial catchment A. H. Ansari The Cryosphere Discuss., doi:10.5194/tc-2016-59,2016 Manuscript under review for TC (discussion: open, 0 comments) The solute chemistry and stable isotope investigation of the snowpack and stream samples demonstrates a large scale microbial NO 3 − -N production (1.64 ± 1.41 kg Day −1 for MLE and 1.41 ± 1.43 kg Day −1 for MLW) and assimilation (1.39 ± 1.41 kg Day −1 for MLE and 1.35 ± 1.43 kg Day −1 for MLW) in the glacier catchment. The microbial nitrate production and consumption are several times higher than the actual nitrate flux of streams therefore infer that microbes play a much greater role in the glacial nitrogen.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 75
    facet.materialart.
    Unknown
    Correction of broadband snow albedo measurements affected by unknown slope and sensor tilts (2016)
    Copernicus
    Details
    Publication Date: 2016-04-07
    Description: Correction of broadband snow albedo measurements affected by unknown slope and sensor tilts Ursula Weiser, Marc Olefs, Wolfgang Schöner, Gernot Weyss, and Bernhard Hynek The Cryosphere, 10, 775-790, doi:10.5194/tc-10-775-2016, 2016 Geometric effects induced by tilt errors lead to erroneous measurement of snow albedo. These errors are corrected where tilts of sensors and slopes are unknown. Atmospheric parameters are taken from a nearby reference measurement or a radiation model. The developed model is fitted to the measured data to determine tilts and directions which vary daily due to changing atmospheric conditions and snow cover. The results show an obvious under- or overestimation of albedo depending on the slope direction.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 76
    facet.materialart.
    Unknown
    Metamorphism during temperature gradient with undersaturated advective airflow in a snow sample (2016)
    Copernicus
    Details
    Publication Date: 2016-04-08
    Description: Metamorphism during temperature gradient with undersaturated advective airflow in a snow sample Pirmin Philipp Ebner, Martin Schneebeli, and Aldo Steinfeld The Cryosphere, 10, 791-797, doi:10.5194/tc-10-791-2016, 2016 Changes of the porous ice structure were observed in a snow sample. Sublimation occurred due to the slight undersaturation of the incoming air into the warmer ice matrix. Diffusion of water vapor opposite to the direction of the temperature gradient counteracted the mass transport of advection. Therefore, the total net ice change was negligible, leading to a constant porosity profile. However, the strong recrystallization of water molecules in snow may impact its isotopic or chemical content.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 77
    facet.materialart.
    Unknown
    Quantifying ice loss in the eastern Himalayas since 1974 using declassified spy satellite imagery (2016)
    Copernicus
    Details
    Publication Date: 2016-04-08
    Description: Quantifying ice loss in the eastern Himalayas since 1974 using declassified spy satellite imagery Joshua M. Maurer, Summer B. Rupper, and Joerg M. Schaefer The Cryosphere Discuss., doi:10.5194/tc-2016-48,2016 Manuscript under review for TC (discussion: open, 0 comments) Here we utilize declassified spy satellite imagery to quantify ice volume loss of glaciers in the eastern Himalayas over approximately the last three decades. Clean-ice and debris-covered glaciers show similar magnitudes of ice loss, while calving glaciers are contributing a disproportionately large amount to total ice loss. Results highlight important physical processes affecting the ice mass budget and associated water resources in the Himalayas.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 78
    facet.materialart.
    Unknown
    Potential use of the N2/Ar ratio as a constraint on the oceanic fixed nitrogen loss (2016)
    Wiley
    Details
    Publication Date: 2016-04-09
    Description: Using a global ocean biogeochemical model, we investigate the suitability of the N 2 /Ar supersaturation ratio (ΔN 2 /Ar) as a tracer of marine nitrogen fixation and denitrification, i.e., the main biological processes that add or remove fixed nitrogen from the ocean. In a series of factorial simulations, we demonstrate that in regions away from the oxygen minimum zones (OMZs) the ΔN 2 /Ar characteristics are mostly determined by benthic denitrification occurring in the deep ocean with minor contributions from benthic and water-column denitrification at shallower depths. In the OMZs, the subsurface maxima of ΔN 2 /Ar are mainly determined by water-column denitrification. In contrast, nitrogen fixation has little impact on ΔN 2 /Ar owing to the rapid loss of the N 2 supersaturation signal through air-sea exchange. We thus conclude that ΔN 2 /Ar can act as a powerful constraint on water column and benthic denitrification occurring in intermediate-to-deep waters, but it cannot be used to estimate nitrogen fixation. The comparison of the currently very limited observations of the ΔN 2 /Ar with our model results shows an acceptable level of agreement, suggesting that the model's prescribed rates and distribution of benthic and water-column denitrification (i.e., 140 and 52 TgN yr -1 , respectively) are reasonable and confirms the results derived from other constraints.
    Print ISSN: 0886-6236
    Electronic ISSN: 1944-9224
    Topics: Biology , Chemistry and Pharmacology , Geography , Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 79
    facet.materialart.
    Unknown
    A century of human-driven changes in the carbon dioxide concentration of lakes (2016)
    Wiley
    Details
    Publication Date: 2016-01-07
    Description: Now that evasion of carbon dioxide (CO 2 ) from inland waters is accounted for in global carbon models, it is crucial to quantify how these fluxes have changed in the past and forecast how they may alter in the future in response to local and global change. Here, we developed a sediment proxy for the concentration of summer surface dissolved CO 2 concentration and used it to reconstruct changes over the past 150 years for three large lakes that have been affected by climate warming, changes in nutrient load and detrital terrigenous supplies. Initially CO 2 -neutral to the atmosphere, all three lakes subsequently fluctuated between near-equilibrium and supersaturation. Although catchment inputs have supplied CO 2 to the lakes, internal processes and re-allocation have ultimately regulated decadal changes in lake surface CO 2 concentration. Nutrient concentration has been the dominant driver of CO 2 variability for a century although the reproducible, non-monotonic relationship of CO 2 to nutrient concentration suggests an interplay between metabolic and chemical processes. Yet, for two of these lakes, climatic control of CO 2 concentrations has been important over the last 30 years, promoting higher surface CO 2 concentrations, likely by decreasing hypolimnetic carbon storage. This new approach offers the unique opportunity to scale, a posteriori , the long-term impact of human activities on lake CO 2 .
    Print ISSN: 0886-6236
    Electronic ISSN: 1944-9224
    Topics: Biology , Chemistry and Pharmacology , Geography , Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 80
    facet.materialart.
    Unknown
    Rapid Anthropogenic Changes in CO2 and pH in the Atlantic Ocean: 2003-2014 (2016)
    Wiley
    Details
    Publication Date: 2016-01-07
    Description: The extended multi-linear regression (eMLR) method is used to determine the uptake and storage of anthropogenic carbon in the Atlantic Ocean based on repeat occupations of 4 cruises from 1989–2014 (A16, A20, A22, and A10), with an emphasis on the 2003–2014 period. The results show a significant increase in basin wide anthropogenic carbon storage in the North Atlantic, which absorbed 4.4 ± 0.9 Pg C decade -1 from 2003–2014 compared to 1.9 ± 0.4 Pg C decade -1 for the 1989–2003 period. This decadal variability is attributed to changing ventilation patterns associated with the North Atlantic Oscillation (NAO) and increasing release of anthropogenic carbon into the atmosphere. There are small changes in the uptake rate of CO 2 in the South Atlantic for these time periods (3.7 ± 0.8 Pg C decade -1 versus 3.2 ± 0.7 Pg C decade -1 ). Several eddies are identified containing ~20% more anthropogenic carbon than the surrounding waters in the South Atlantic demonstrating the importance of eddies in transporting anthropogenic carbon. The uptake of carbon results in a decrease in pH of ~0.0021 ± 0.0007 yr -1 for surface waters during the last 10 years, in line with the atmospheric increase in CO 2 .
    Print ISSN: 0886-6236
    Electronic ISSN: 1944-9224
    Topics: Biology , Chemistry and Pharmacology , Geography , Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 81
    facet.materialart.
    Unknown
    Long-term P weathering and recent N deposition control contemporary plant-soil C, N and P (2016)
    Wiley
    Details
    Publication Date: 2016-01-07
    Description: Models are needed to understand how plant-soil nutrient stores and fluxes have responded to the last two centuries of widespread anthropogenic nutrient pollution and predict future change. These models need to integrate across carbon, nitrogen and phosphorus (C, N, & P) cycles and simulate changes over suitable timescales using available driving data. It is also vital that they are constrainable against observed data to provide confidence in their outputs. To date, no models address all of these requirements. To meet this need, a new model, N14CP, is introduced, which is initially applied to Northern hemisphere temperate and boreal ecosystems over the Holocene. N14CP is parameterized and tested using 88 northern Europe plot-scale studies, providing the most robust test of such a model to date. The model simulates long-term P weathering, based on the assumption of a starting pool of weatherable P ( P weath0 , g m −2 ), which is gradually transformed into organic and sorbed pools. Nitrogen fixation (and consequently primary production) is made dependent on available P. In the absence of knowledge about the spatial variability of P weath0 , N14CP produces good average soil and plant variables, but cannot simulate variations among sites. Allowing P weath0 to vary between sites improves soil C, N and P results greatly, suggesting contemporary soil C, N and P are sensitive to long-term P weathering. Most sites were found to be N limited. Anthropogenic N deposition since 1800 was calculated to have increased plant biomass substantially, in agreement with observations, and consequently increased soil carbon pools.
    Print ISSN: 0886-6236
    Electronic ISSN: 1944-9224
    Topics: Biology , Chemistry and Pharmacology , Geography , Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 82
    facet.materialart.
    Unknown
    Mercury presence and speciation in the South Atlantic Ocean along the 40°S transect (2016)
    Wiley
    Details
    Publication Date: 2016-01-09
    Description: Mercury (Hg) natural biogeochemical cycle is complex and a significant portion of biological and chemical transformation occurs in the marine environment. To better understand the presence and abundance of Hg species in the remote ocean regions, waters of South Atlantic Ocean along 40°S parallel were investigated during UK-GEOTRACES cruise GA10. Total mercury (THg), methylated mercury (MeHg) and dissolved gaseous mercury (DGM) concentrations were determined. The concentrations were very low in the range of pg/L (femtomolar). All Hg species had higher concentration in western than in eastern basin. THg did not appear to be a useful geotracer. Elevated methylated Hg species were commonly associated with low-oxygen water masses and occasionally with peaks of Chlorophyll a , both involved with carbon (re)cycling. The overall highest MeHg concentrations were observed in the mixed layer (500 m) and in the vicinity of the Gough Island.. Conversely, DGM concentrations showed distinct layering and differed between the water masses in a nutrient-like manner. DGM was lowest at surface, indicating degassing to the atmosphere; and was highest in the Upper Circumpolar Deep Water, where the oxygen concentration was lowest. DGM increased also in Antarctic Bottom Water. At one station, dimethylmercury was determined and showed increase in region with lowest oxygen saturation. Altogether, our data indicate that the South Atlantic Ocean could be a source of Hg to the atmosphere and that its biogeochemical transformations depend primarily upon carbon cycling and are thereby additionally prone to global ocean change.
    Print ISSN: 0886-6236
    Electronic ISSN: 1944-9224
    Topics: Biology , Chemistry and Pharmacology , Geography , Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 83
    facet.materialart.
    Unknown
    Annual cycles of phytoplankton biomass in the Subarctic Atlantic and Pacific Ocean (2016)
    Wiley
    Details
    Publication Date: 2016-01-09
    Description: High latitude phytoplankton blooms support productive fisheries and play an important role in oceanic uptake of atmospheric carbon dioxide. In the subarctic North Atlantic Ocean, blooms are a recurrent feature each year, while in the eastern subarctic Pacific only small changes in chlorophyll (Chl) are seen over the annual cycle. Here, we show that when evaluated using phytoplankton carbon biomass (C phyto ) rather than Chl, an annual bloom in the North Pacific is evident and can even rival blooms observed in the North Atlantic. The annual increase in subarctic Pacific phytoplankton biomass is not readily observed in the Chl record because it is paralleled by light- and nutrient-driven decreases in cellular pigment levels (C phyto :Chl). Specifically, photoacclimation and iron stress effects on C phyto :Chl oppose the biomass increase, leading to only modest changes in bulk Chl. The magnitude of the photoacclimation effect is quantified using descriptors of the near-surface light environment and a photophysiological model. Iron-stress effects are diagnosed from satellite chlorophyll fluorescence data. Last, we show that biomass accumulation in the Pacific is slower than the Atlantic, but is closely tied to similar levels of seasonal nutrient uptake in both basins. Annual cycles of satellite-derived Chl and C phyto are reproduced by in situ autonomous profiling floats. These results contradict the long-standing paradigm that environmental conditions prevent phytoplankton accumulation in the subarctic Northeast Pacific and suggest a greater seasonal decoupling between phytoplankton growth and losses than traditionally implied. Further, our results highlight the role of physiological processes in shaping bulk properties, such as Chl, and their interpretation in studies of ocean ecosystem dynamics and climate change.
    Print ISSN: 0886-6236
    Electronic ISSN: 1944-9224
    Topics: Biology , Chemistry and Pharmacology , Geography , Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 84
    facet.materialart.
    Unknown
    Net community production and calcification from seven years of NOAA Station Papa Mooring measurements (2016)
    Wiley
    Details
    Publication Date: 2016-01-09
    Description: Seven years of near-continuous observations from the Ocean Station Papa (OSP) surface mooring were used to evaluate drivers of marine carbon cycling in the eastern subarctic Pacific. Processes contributing to mixed layer carbon inventory changes throughout each deployment year were quantitatively assessed using a time-dependent mass-balance approach in which total alkalinity and dissolved inorganic carbon were used as tracers. By using two mixed layer carbon tracers it was possible to isolate the influences of net community production (NCP) and calcification. Our results indicate that the annual NCP at OSP is 2 ± 1 mol C m -2 yr -1 and the annual calcification is 0.3 ± 0.3 mol C m -2 yr -1 . Piecing together evidence for potentially significant dissolved organic carbon cycling in this region, we estimate a particulate inorganic carbon to particulate organic carbon ratio between 0.15 and 0.25. This is at least double the global average, adding to the growing evidence that calcifying organisms play an important role in carbon export at this location. These results, coupled with significant seasonality in the NCP, suggest that carbon cycling near OSP may be more complex than previously thought, and highlight the importance of continuous observations for robust assessments of biogeochemical cycling.
    Print ISSN: 0886-6236
    Electronic ISSN: 1944-9224
    Topics: Biology , Chemistry and Pharmacology , Geography , Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 85
    facet.materialart.
    Unknown
    Recent summer sea ice thickness surveys in Fram Strait and associated ice volume fluxes (2016)
    Copernicus
    Details
    Publication Date: 2016-03-09
    Description: Recent summer sea ice thickness surveys in Fram Strait and associated ice volume fluxes T. Krumpen, R. Gerdes, C. Haas, S. Hendricks, A. Herber, V. Selyuzhenok, L. Smedsrud, and G. Spreen The Cryosphere, 10, 523-534, doi:10.5194/tc-10-523-2016, 2016 We present an extensive data set of ground-based and airborne electromagnetic ice thickness measurements covering Fram Strait in summer between 2001 and 2012. An investigation of back trajectories of surveyed sea ice using satellite-based sea ice motion data allows us to examine the connection between thickness variability, ice age and source area. In addition, we determine across and along strait gradients in ice thickness and associated volume fluxes.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 86
    facet.materialart.
    Unknown
    Longitudinal distributions of dicarboxylic acids, ω-oxoacids, pyruvic acid, α-dicarbonyls and fatty acids in the marine aerosols from the central Pacific including equatorial upwelling (2016)
    Wiley
    Details
    Publication Date: 2016-03-10
    Description: Remote marine aerosol samples (total suspended particles, TSP) were collected during a cruise in the central Pacific from Japan to Mexico (1°59’N-35°N and 171°54’E-90°58’W). The aerosol samples were analyzed for dicarboxylic acids (C 2 -C 11 ), ω-oxoacids, pyruvic acid, α-dicarbonyls and fatty acids as well as organic and elemental carbon (OC/EC), water-soluble organic carbon (WSOC) and total nitrogen (WSTN). During the study, diacids were the most abundant compound class followed by fatty acids, ω-oxoacids and α-dicarbonyls. Molecular compositions of diacids showed a predominance of oxalic (C 2 ) acid followed by malonic (C 3 ) and succinic (C 4 ) acids. Oxalic acid comprises 74% of total diacids. This result suggests that photochemical production of oxalic acid is significant over the central Pacific. Spatial distributions of diacids, ω-oxoacids, pyruvic acid, α-dicarbonyls and fatty acids together with TC and WSTN showed higher abundances in the eastern equatorial Pacific where the upwelling of high nutrient waters followed by high biological productivity is common, indicating that their in-situ production is important in the warmer central Pacific through photochemical oxidation from their gaseous and particulate precursors. This study demonstrates that there is a strong linkage in biogeochemical cycles of carbon in the sea-air interface via ocean upwelling, phytoplankton productivity, sea-to-air emissions of organic matter and formation of secondary organic aerosols in the eastern equatorial Pacific.
    Print ISSN: 0886-6236
    Electronic ISSN: 1944-9224
    Topics: Biology , Chemistry and Pharmacology , Geography , Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 87
    facet.materialart.
    Unknown
    Scaling-up Permafrost Thermal Measurements in Western Alaska using an Ecotype Approach (2016)
    Copernicus
    Details
    Publication Date: 2016-03-03
    Description: Scaling-up Permafrost Thermal Measurements in Western Alaska using an Ecotype Approach William L. Cable, Vladimir E. Romanovsky, and M. Torre Jorgenson The Cryosphere Discuss., doi:10.5194/tc-2016-30,2016 Manuscript under review for TC (discussion: open, 0 comments) Permafrost temperatures in Alaska are increasing, yet in many areas we lack data needed to assess future changes and potential risks. In this paper we show that classifying the landscape into landcover types is an effective way to scale up permafrost temperature data collected from field monitoring sites. Based on these results, a map of mean annual ground temperature ranges at 1 m depth was produced. The map should be useful for land use decision making and identifying potential risk areas.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 88
    facet.materialart.
    Unknown
    The darkening of the Greenland ice sheet: trends, drivers, and projections (1981–2100) (2016)
    Copernicus
    Details
    Publication Date: 2016-03-04
    Description: The darkening of the Greenland ice sheet: trends, drivers, and projections (1981–2100) Marco Tedesco, Sarah Doherty, Xavier Fettweis, Patrick Alexander, Jeyavinoth Jeyaratnam, and Julienne Stroeve The Cryosphere, 10, 477-496, doi:10.5194/tc-10-477-2016, 2016 Summer surface albedo over Greenland decreased at a rate of 0.02 per decade between 1996 and 2012. The decrease is due to snow grain growth, the expansion of bare ice areas, and trends in light-absorbing impurities on snow and ice surfaces. Neither aerosol models nor in situ observations indicate increasing trends in impurities in the atmosphere over Greenland. Albedo projections through to the end of the century under different warming scenarios consistently point to continued darkening.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 89
    facet.materialart.
    Unknown
    Brief Communication: Evidence of a developing Polynya off Commonwealth Bay, East Antarctica, triggered by grounding of iceberg (2016)
    Copernicus
    Details
    Publication Date: 2016-03-08
    Description: Brief Communication: Evidence of a developing Polynya off Commonwealth Bay, East Antarctica, triggered by grounding of iceberg Christopher J. Fogwill, Erik van Sebille, Eva A. Cougnon, Chris S. M. Turney, Steve R. Rintoul, Graeme F. Clark, E. M. Marzinelli, Eleanor B. Rainsley, and Lionel Carter The Cryosphere Discuss., doi:10.5194/tc-2016-19,2016 Manuscript under review for TC (discussion: open, 0 comments) Here we report new data from in situ oceanographic surveys and high-resolution ocean modelling experiments in the Commonwealth Bay region of East Antarctica, where in 2010 there was a major reconfiguration of the regional ice-scape due to the collision of the 97 km long iceberg B09B with the Mertz Glacier Tongue. Here we compare post-calving observations with high-resolution ocean modelling which suggest that this reconfiguration has led to the development of a new polynya off Commonwealth Bay.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 90
    facet.materialart.
    Unknown
    A fully automated methodology for differentiating rock from snow, clouds and sea in Antarctica from Landsat imagery: A new rock outcrop map and area estimation for the entire Antarctic continent (2016)
    Copernicus
    Details
    Publication Date: 2016-03-08
    Description: A fully automated methodology for differentiating rock from snow, clouds and sea in Antarctica from Landsat imagery: A new rock outcrop map and area estimation for the entire Antarctic continent Alex Burton-Johnson, Martin Black, Peter T. Fretwell, and Joseph Kaluza-Gilbert The Cryosphere Discuss., doi:10.5194/tc-2016-56,2016 Manuscript under review for TC (discussion: open, 0 comments) Differentiating exposed rock from snow and ice is a particular problem in Antarctica where extensive cloud cover and widespread shaded regions lead to classification errors. The existing rock outcrop dataset has significant georeferencing issues including overestimation and generalisation of rock exposure areas. The most commonly used method for automated rock and snow differentiation, the Normalised Difference Snow Index (NDSI), has difficulty differentiating rock and snow in Antarctica due to misclassification of shaded pixels and cannot differentiate illuminated rock from clouds. This study presents a new method for identifying rock exposures using Landsat 8 data. This is the first fully automated methodology for snow and rock differentiation that excludes areas of snow (both illuminated and shaded), clouds and liquid water whilst identifying both sunlit and shaded rock, achieving higher and more consistent accuracies than alternative data and methods such as the NDSI. The new methodology has been applied to the whole Antarctic continent (north of 82°40' S) using Landsat 8 data to produce a new rock outcrop dataset for Antarctica. The new data (merged with existing data south of 82°40' S) reveals that exposed rock forms 0.18 % of the total land area of Antarctica; half of previous estimates.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 91
    facet.materialart.
    Unknown
    Use of an ultra-long-range terrestrial laser scanner to monitor the mass balance of very small glaciers in the Swiss Alps (2016)
    Copernicus
    Details
    Publication Date: 2016-03-09
    Description: Use of an ultra-long-range terrestrial laser scanner to monitor the mass balance of very small glaciers in the Swiss Alps Mauro Fischer, Matthias Huss, Mario Kummert, and Martin Hoelzle The Cryosphere Discuss., doi:10.5194/tc-2016-46,2016 Manuscript under review for TC (discussion: open, 0 comments) Due to the relative lack of empirical field data, the response of very small glaciers ( 〈 0.5 km 2 ) to current atmospheric warming is not fully understood yet. Investigating their mass balance is a prerequisite to fill this knowledge gap. Application of the direct glaciological method is one option. Since most recently, terrestrial laser scanning (TLS) techniques operating in the near infrared range are successfully applied for the creation of repeated high-resolution digital elevation models and consecutive derivation of annual geodetic mass balances of very small glaciers. This method is promising, as laborious and potentially dangerous field measurements as well as the inter- and extrapolation of point measurements can be circumvented. However, it still owes to be validated. Here, we present TLS-derived annual surface elevation and geodetic mass changes for five very small glaciers in Switzerland (Glacier de Prapio, Glacier du Sex Rouge, St. Annafirn, Schwarzbachfirn, and Pizolgletscher) and two consecutive years (2013/14–2014/15). The scans were acquired with an ultra-long-range Riegl VZ-6000 especially designed for surveying snow- and ice-covered terrain. Zonally variable conversion factors for firn and bare ice surfaces were applied to convert geodetic volume to mass changes. We compare the geodetic results to direct glaciological mass balance measurements coinciding with the TLS surveys and carefully assess the uncertainties and errors included in both methods. Average glacier-wide mass balances were negative in both years, showing remarkably stronger mass losses in 2014/15 (−1.65 m w.e.) compared to 2013/14 (−0.59 m w.e.). Geodetic mass balances were slightly less negative but in close agreement with the direct glaciological ones ( R 2 = 0.91). Due to the very dense in-situ measurements, the uncertainties in the direct glaciological mass balances were small compared to the majority of measured glaciers worldwide (±0.09 m w.e. yr −1 on average), and similar to uncertainties in the TLS-derived geodetic mass balances (±0.13 m w.e. yr −1 ).
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 92
    facet.materialart.
    Unknown
    Reanalysis of long-term series of glaciological and geodetic mass balance for 10 Norwegian glaciers (2016)
    Copernicus
    Details
    Publication Date: 2016-03-09
    Description: Reanalysis of long-term series of glaciological and geodetic mass balance for 10 Norwegian glaciers Liss M. Andreassen, Hallgeir Elvehøy, Bjarne Kjøllmoen, and Rune V. Engeset The Cryosphere, 10, 535-552, doi:10.5194/tc-10-535-2016, 2016 This study provides homogenised and partly calibrated data series of glaciological and geodetic mass balance for the 10 Norwegian glaciers with long-term observations. In total, 21 periods of data were compared. Uncertainties were quantified for relevant sources of errors, both in the glaciological and geodetic series. The reanalysis processes altered seasonal, annual, and cumulative as well as ELA and AAR values for many of the years for the 10 glaciers presented.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 93
    facet.materialart.
    Unknown
    Microzooplankton regulation of surface ocean POC:PON ratios (2016)
    Wiley
    Details
    Publication Date: 2016-01-14
    Description: The elemental composition of particulate organic matter in the surface ocean significantly affects the efficiency of the oceanâĂŹs store of carbon. Though the elemental composition of primary producers is an important factor, recent observations from the western North Atlantic Ocean revealed that carbon-to-nitrogen ratios (C:N) of phytoplankton were significantly higher than the relatively homeostatic ratio of the total particulate pool (Particulate Organic Carbon: Particulate Organic Nitrogen; POC:PON). Here we use an idealized ecosystem model to show how interactions between primary and secondary producers maintain the mean composition of surface particulates, and the difference between primary producers and bulk material. Idealized physiological models of phytoplankton and microzooplankton, constrained by laboratory data, reveal contrasting autotrophic and heterotrophic responses to nitrogen limitation: under nitrogen limitation, phytoplankton accumulate carbon in carbohydrates and lipids while microzooplankton deplete internal C reserves to fuel respiration. Global ecosystem simulations yield hypothetical global distributions of phytoplankton and microzooplankton C:N ratio predicting elevated phytoplankton C:N ratios in the high light, low nutrient regions of the ocean despite a lower, homeostatic POC:PON ratio due to respiration of excess carbon in systems subject to top-down control. The model qualitatively captures, and provides a simple interpretation for, a global compilation of surface ocean POC:PON data.
    Print ISSN: 0886-6236
    Electronic ISSN: 1944-9224
    Topics: Biology , Chemistry and Pharmacology , Geography , Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 94
    facet.materialart.
    Unknown
    Nitrogen trace gas fluxes from a semi-arid subtropical savanna under woody legume encroachment (2016)
    Wiley
    Details
    Publication Date: 2016-04-01
    Description: Savanna ecosystems are a major source of nitrogen (N) trace gases that influence air quality and climate. These systems are experiencing widespread encroachment by woody plants, frequently associated with large increases in soil N, with no consensus on implications for trace gas emissions. We investigated the impact of encroachment by N-fixing tree Prosopis glandulosa on total reactive N gas flux (N t  = NO + N 2 O + NO y  + NH 3 ) from south Texas savanna soils over two years. Contrary to expectations, upland Prosopis groves did not have greater N t fluxes than adjacent unencroached grasslands. However, abiotic conditions (temperature, rainfall, and topography) were strong drivers. Emissions from moist, low-lying Prosopis playas were up to three times higher than from Prosopis uplands. Though NO dominated emissions, NH 3 and NO y (non-NO oxidized N) comprised 12-16% of the total summer N flux (up to 7.9 µg N m -2 h -1 ). Flux responses to soil wetting were temperature-dependent for NO, NH 3 and NO y : a 15 mm rainfall event increased flux 3-22 fold after 24 hours in summer, but had no effect in winter. Repeated soil wetting reduced N flux responses, indicating substrate depletion as a likely control. Rapid (〈1 min) increases in NO emissions following wetting of dry soils suggested that abiotic chemodenitrification contributes to pulse emissions. We conclude that temperature and wetting dynamics, rather than encroachment, are primary drivers of N flux from these upland savannas, with implications for future emission patterns under altered precipitation regimes.
    Print ISSN: 0886-6236
    Electronic ISSN: 1944-9224
    Topics: Biology , Chemistry and Pharmacology , Geography , Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 95
    facet.materialart.
    Unknown
    The influence of a model subglacial lake on ice dynamics and internal layering (2016)
    Copernicus
    Details
    Publication Date: 2016-04-06
    Description: The influence of a model subglacial lake on ice dynamics and internal layering Eythor Gudlaugsson, Angelika Humbert, Thomas Kleiner, Jack Kohler, and Karin Andreassen The Cryosphere, 10, 751-760, doi:10.5194/tc-10-751-2016, 2016 This paper explores the influence of a subglacial lake on ice dynamics and internal layers by means of numerical modelling as well as simulating the effect of a subglacial drainage event on isochrones. We provide an explanation for characteristic dip and ridge features found at the edges of many subglacial lakes and conclude that draining lakes can result in travelling waves at depth within isochrones, thus indicating the possibility of detecting past drainage events with ice penetrating radar.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 96
    facet.materialart.
    Unknown
    Multi-level spatiotemporal validation of snow/ice mass balance and runoff modeling in glacierized catchments (2016)
    Copernicus
    Details
    Publication Date: 2016-04-06
    Description: Multi-level spatiotemporal validation of snow/ice mass balance and runoff modeling in glacierized catchments Florian Hanzer, Kay Helfricht, Thomas Marke, and Ulrich Strasser The Cryosphere Discuss., doi:10.5194/tc-2016-58,2016 Manuscript under review for TC (discussion: open, 0 comments) The hydroclimatological model AMUNDSEN is set up to simulate snow and ice accumulation, ablation, and runoff for a study region in the Ötztal Alps (Austria) in the period 1997–2013. A new validation concept is introduced and demonstrated by evaluating the model performance using several independent data sets, e.g. snow depth measurements, satellite-derived snow maps, lidar data, glacier mass balances, and runoff measurements.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 97
    facet.materialart.
    Unknown
    A Maxwell elasto-brittle rheology for sea ice modelling (2016)
    Copernicus
    Details
    Publication Date: 2016-07-02
    Description: A Maxwell elasto-brittle rheology for sea ice modelling Véronique Dansereau, Jérôme Weiss, Pierre Saramito, and Philippe Lattes The Cryosphere, 10, 1339-1359, doi:10.5194/tc-10-1339-2016, 2016 In this paper we present a new mechanical modelling framework for the deformation of sea ice on regional and larger scales named Maxwell elasto-brittle. The model successfully reproduces the formation of narrow, oriented leads which concentrate the deformation within the damaged, i.e., fractured, ice as well as the intermittency of the damaging process, and hence represents a relevant contribution to the ongoing development of operational modelling platforms, regional and global climate models.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 98
    facet.materialart.
    Unknown
    Glacier change and glacial lake outburst flood risk in the Bolivian Andes (2016)
    Copernicus
    Details
    Publication Date: 2016-07-02
    Description: Glacier change and glacial lake outburst flood risk in the Bolivian Andes Simon J. Cook, Ioannis Kougkoulos, Laura A. Edwards, Jason Dortch, and Dirk Hoffmann The Cryosphere Discuss., doi:10.5194/tc-2016-140,2016 Manuscript under review for TC (discussion: open, 0 comments) This is the first study of recent glacier change for the whole of the Bolivian Cordillera Oriental from 1986 to 2014. These glaciers have shrunk by ~ 43 %, which is a concern for regional water resources. We provide the first quantification of meltwater lake development across the Bolivian Andes as glaciers have receded. These lakes have increased markedly in number and area. We identify 25 lakes as potential outburst flood risks to downstream communities. These lakes require further monitoring.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 99
    facet.materialart.
    Unknown
    Refinement of the ice absorption spectrum in the visible using radiance profile measurements in Antarctic snow (2016)
    Copernicus
    Details
    Publication Date: 2016-07-02
    Description: Refinement of the ice absorption spectrum in the visible using radiance profile measurements in Antarctic snow Ghislain Picard, Quentin Libois, and Laurent Arnaud The Cryosphere Discuss., doi:10.5194/tc-2016-146,2016 Manuscript under review for TC (discussion: open, 0 comments) The absorption of visible light in ice is very weak but its precise value is unknown. By measuring the profile of light intensity in snow, Warren and Brand (2006) deduced that light is attenuated by a factor 2 per kilometer in pure ice at a wavelength of 400 nm. We replicated their experiment on a large number of samples and found that ice absorption is at least 10 times stronger. The paper explores various potential physical and statistical biases that could impact the experiment.
    Print ISSN: 1994-0416
    Electronic ISSN: 1994-0424
    Topics: Geography , Geosciences
    Published by Copernicus on behalf of The European Geosciences Union (EGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 100
    facet.materialart.
    Unknown
    Origins, Seasonality and Fluxes of Organic Matter in the Congo River (2016)
    Wiley
    Details
    Publication Date: 2016-07-06
    Description: The Congo River in central Africa represents a major source of organic matter (OM) to the Atlantic Ocean. This study examined elemental (%OC, %N, C:N), stable isotopic (δ 13 C, δ 15 N) and biomarker composition (lignin phenols) of particulate OM (POM) and dissolved OM (DOM) across the seasonal hydrograph. Even though the Congo exhibits an extremely stable intraannual discharge regime, seasonal variability in OM composition was evident. DOM appears predominantly derived from vascular plant inputs with greater relative contribution during the rising limb and peak in discharge associated with the major November-December discharge maximum. Generally, POM appears to be sourced from soil-derived mineral-associated OM (low C:N, low Λ 8 , higher (Ad:Al) v ) but the relative proportion of fresh vascular plant material (higher C:N, higher Λ 8 , lower (Ad:Al) v ) increases with higher discharge. During the study period (September 2009-November 2010) the Congo exported 29.21 Tg yr -1 of total suspended sediment (TSS), 1.96 Tg yr -1 of particulate organic carbon (POC) and 12.48 Tg yr -1 of dissolved organic carbon (DOC). The Congo exports an order of magnitude lower TSS load in comparison to other major riverine sources of TSS (e.g. Ganges, Brahmaputra), but due to its OM rich character actually exports a comparable amount of POC. The Congo is also 2.5 times more efficient at exporting dissolved lignin per unit volume compared to the Amazon. Including Congo dissolved lignin data in residence time calculations for lignin in the Atlantic Ocean results in an approximately 10% reduction from the existing estimate, suggesting this material is more reactive than previously thought.
    Print ISSN: 0886-6236
    Electronic ISSN: 1944-9224
    Topics: Biology , Chemistry and Pharmacology , Geography , Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...