ALBERT

Description / Table of Contents: Climate change of anthropogenic origin is affecting Earth’s biodiversity and therefore ecosystems and their services. High latitude ecosystems are even more impacted than the rest of Northern Hemisphere because of the amplified polar warming. Still, it is challenging to predict the dynamics of high latitude ecosystems because of complex interaction between abiotic and biotic components. As the past is the key to the future, the interpretation of past ecological changes to better understand ongoing processes is possible. In the Quaternary, the Pleistocene experienced several glacial and interglacial stages that affected past ecosystems. During the last Glacial, the Pleistocene steppe-tundra was covering most of unglaciated northern hemisphere and disappeared in parallel to the megafauna’s extinction at the transition to the Holocene (~11,700 years ago). The origin of the steppe-tundra decline is not well understood and knowledge on the mechanisms, which caused shifts in past communities and ecosystems, is of high priority as they are likely comparable to those affecting modern ecosystems. Lake or permafrost core sediments can be retrieved to investigate past biodiversity at transitions between glacial and interglacial stages. Siberia and Beringia were the origin of dispersal of the steppe-tundra, which make investigation this area of high priority. Until recently, macrofossils and pollen were the most common approaches. They are designed to reconstruct past composition changes but have limit and biases. Since the end of the 20th century, sedimentary ancient DNA (sedaDNA) can also be investigated. My main objectives were, by using sedaDNA approaches to provide scientific evidence of compositional and diversity changes in the Northern Hemisphere ecosystems at the transition between Quaternary glacial and interglacial stages. In this thesis, I provide snapshots of entire ancient ecosystems and describe compositional changes between Quaternary glacial and interglacial stages, and confirm the vegetation composition and the spatial and temporal boundaries of the Pleistocene steppe-tundra. I identify a general loss of plant diversity with extinction events happening in parallel of megafauna’ extinction. I demonstrate how loss of biotic resilience led to the collapse of a previously well-established system and discuss my results in regards to the ongoing climate change. With further work to constrain biases and limits, sedaDNA can be used in parallel or even replace the more established macrofossils and pollen approaches as my results support the robustness and potential of sedaDNA to answer new palaeoecological questions such as plant diversity changes, loss and provide snapshots of entire ancient biota.

Description / Table of Contents: Der vom Menschen verursachte Klimawandel wirkt sich auf die biologische Vielfalt der Erde und damit auf die Ökosysteme und ihre Leistungen aus. Die Ökosysteme in den hohen Breitengraden sind aufgrund der verstärkten Erwärmung an den Polen noch stärker betroffen als der Rest der nördlichen Hemisphäre. Dennoch ist es schwierig, die Dynamik von Ökosystemen in den hohen Breitengraden vorherzusagen, da die Wechselwirkungen zwischen abiotischen und biotischen Komponenten sehr komplex sind. Da die Vergangenheit der Schlüssel zur Zukunft ist, ist die Interpretation vergangener ökologischer Veränderungen möglich, um laufende Prozesse besser zu verstehen. Im Quartär durchlief das Pleistozän mehrere glaziale und interglaziale Phasen, welche die Ökosysteme der Vergangenheit beeinflussten. Während des letzten Glazials bedeckte die pleistozäne Steppentundra den größten Teil der unvergletscherten nördlichen Hemisphäre und verschwand parallel zum Aussterben der Megafauna am Übergang zum Holozän (vor etwa 11 700 Jahren). Der Ursprung des Rückgangs der Steppentundra ist nicht gut erforscht, und die Kenntnis über die Mechanismen, die zu den Veränderungen in den vergangenen Lebensgemeinschaften und Ökosystemen geführt haben, ist von hoher Priorität, da sie wahrscheinlich mit denen vergleichbar sind, die sich auf moderne Ökosysteme auswirken. Durch die Entnahme von See- oder Permafrostkernsedimenten kann die vergangene Artenvielfalt an den Übergängen zwischen Eis- und Zwischeneiszeiten untersucht werden. Sibirien und Beringia waren der Ursprung der Ausbreitung der Steppentundra, weshalb die Untersuchung dieses Gebiets hohe Priorität hat. Bis vor kurzem waren Makrofossilien und Pollen die gängigsten Methoden. Sie dienen der Rekonstruktion vergangener Veränderungen in der Zusammensetzung der Bevölkerung, haben aber ihre Grenzen und Schwächen. Seit Ende des 20. Jahrhunderts kann auch sedimentäre alte DNA (sedaDNA) untersucht werden. Mein Hauptziel war es, durch den Einsatz von sedaDNA-Ansätzen wissenschaftliche Beweise für Veränderungen in der Zusammensetzung und Vielfalt der Ökosysteme der nördlichen Hemisphäre am Übergang zwischen den quartären Eiszeiten und Zwischeneiszeiten zu liefern. In dieser Arbeit liefere ich Momentaufnahmen ganzer alter Ökosysteme und beschreibe die Veränderungen in der Zusammensetzung zwischen Quartärglazialen und Interglazialen und bestätige die Vegetationszusammensetzung sowie die räumlichen und zeitlichen Grenzen der pleistozänen Steppentundra. Ich stelle einen allgemeinen Verlust der Pflanzenvielfalt fest, wobei das Aussterben der Pflanzen parallel zum Aussterben der Megafauna verlief. Ich zeige auf, wie der Verlust der biotischen Widerstandsfähigkeit zum Zusammenbruch eines zuvor gut etablierten Systems führte, und diskutiere meine Ergebnisse im Hinblick auf den laufenden Klimawandel. Mit weiteren Arbeiten zur Eingrenzung von Verzerrungen und Grenzen kann sedaDNA parallel zu den etablierteren Makrofossilien- und Pollenansätzen verwendet werden oder diese sogar ersetzen, da meine Ergebnisse die Robustheit und das Potenzial von sedaDNA zur Beantwortung neuer paläoökologischer Fragen wie Veränderungen der Pflanzenvielfalt und -verluste belegen und Momentaufnahmen ganzer alter Biota liefern.

Description / Table of Contents: This book, entitled Tracking Environmental Change Using Lake Sediments: Volume 6 – Sedimentary DNA, provides an overview of the applications of sedimentary DNA-based approaches to paleolimnological studies. These approaches have shown considerable potential in providing information about the long-term changes of overall biodiversity in lakes and their watersheds in response to natural and anthropogenic changes, as well as tracking human migrations over the last thousands of years. Although the first studies investigating the preservation of these molecular proxies in sediments originate from the late-1990s, the number of scientific publications on this topic has increased greatly over the last five years. Alongside numerous ecological findings, several sedimentary DNA studies have been dedicated to understanding the reliability of this approach to reconstruct past ecosystem changes. Despite the major surge of interest, a comprehensive compilation of sedimentary DNA approaches and applications has yet to be attempted. The overall aim of this DPER volume is to fill this knowledge gap.

Description / Table of Contents: With Arctic ground as a huge and temperature-sensitive carbon reservoir, maintaining low ground temperatures and frozen conditions to prevent further carbon emissions that contrib-ute to global climate warming is a key element in humankind’s fight to maintain habitable con-ditions on earth. Former studies showed that during the late Pleistocene, Arctic ground condi-tions were generally colder and more stable as the result of an ecosystem dominated by large herbivorous mammals and vast extents of graminoid vegetation – the mammoth steppe. Characterised by high plant productivity (grassland) and low ground insulation due to animal-caused compression and removal of snow, this ecosystem enabled deep permafrost aggrad-ation. Now, with tundra and shrub vegetation common in the terrestrial Arctic, these effects are not in place anymore. However, it appears to be possible to recreate this ecosystem local-ly by artificially increasing animal numbers, and hence keep Arctic ground cold to reduce or-ganic matter decomposition and carbon release into the atmosphere. By measuring thaw depth, total organic carbon and total nitrogen content, stable carbon iso-tope ratio, radiocarbon age, n-alkane and alcohol characteristics and assessing dominant vegetation types along grazing intensity transects in two contrasting Arctic areas, it was found that recreating conditions locally, similar to the mammoth steppe, seems to be possible. For permafrost-affected soil, it was shown that intensive grazing in direct comparison to non-grazed areas reduces active layer depth and leads to higher TOC contents in the active layer soil. For soil only frozen on top in winter, an increase of TOC with grazing intensity could not be found, most likely because of confounding factors such as vertical water and carbon movement, which is not possible with an impermeable layer in permafrost. In both areas, high animal activity led to a vegetation transformation towards species-poor graminoid-dominated landscapes with less shrubs. Lipid biomarker analysis revealed that, even though the available organic material is different between the study areas, in both permafrost-affected and sea-sonally frozen soils the organic material in sites affected by high animal activity was less de-composed than under less intensive grazing pressure. In conclusion, high animal activity af-fects decomposition processes in Arctic soils and the ground thermal regime, visible from reduced active layer depth in permafrost areas. Therefore, grazing management might be utilised to locally stabilise permafrost and reduce Arctic carbon emissions in the future, but is likely not scalable to the entire permafrost region.

Description / Table of Contents: This atlas is an attempt to translate and consolidate the available knowledge on permafrost. It is a timely book suffused with the compelling enthusiasm of its authors and contributors. Close to a hundred individuals participated in its making, and it does a magnificent job at describing permafrost with maps, words, art, and stories. Far from being an academic product in the traditional sense, it gathers the knowledge from the voices of scientists, Indigenous Peoples, northern residents, and local practitioners to provide a holistic and inclusive view of today’s challenges in the “country of permafrost”.

Description / Table of Contents: Extreme weather and climate events are one of the greatest dangers for present-day society. Therefore, it is important to provide reliable statements on what changes in extreme events can be expected along with future global climate change. However, the projected overall response to future climate change is generally a result of a complex interplay between individual physical mechanisms originated within the different climate subsystems. Hence, a profound understanding of these individual contributions is required in order to provide meaningful assessments of future changes in extreme events. One aspect of climate change is the recently observed phenomenon of Arctic Amplification and the related dramatic Arctic sea ice decline, which is expected to continue over the next decades. The question to what extent Arctic sea ice loss is able to affect atmospheric dynamics and extreme events over mid-latitudes has received a lot of attention over recent years and still remains a highly debated topic. In this respect, the objective of ...

Description / Table of Contents: The icosahedral non-hydrostatic large eddy model (ICON-LEM) was applied around the drift track of the Multidisciplinary Observatory Study of the Arctic (MOSAiC) in 2019 and 2020. The model was set up with horizontal grid-scales between 100m and 800m on areas with radii of 17.5km and 140 km. At its lateral boundaries, the model was driven by analysis data from the German Weather Service (DWD), downscaled by ICON in limited area mode (ICON-LAM) with horizontal grid-scale of 3 km. The aim of this thesis was the investigation of the atmospheric boundary layer near the surface in the central Arctic during polar winter with a high-resolution mesoscale model. The default settings in ICON-LEM prevent the model from representing the exchange processes in the Arctic boundary layer in accordance to the MOSAiC observations. The implemented sea-ice scheme in ICON does not include a snow layer on sea-ice, which causes a too slow response of the sea-ice surface temperature to atmospheric changes. To allow the sea-ice surface to respond faster to changes in the atmosphere, the implemented sea-ice parameterization in ICON was extended with an adapted heat capacity term. The adapted sea-ice parameterization resulted in better agreement with the MOSAiC observations. However, the sea-ice surface temperature in the model is generally lower than observed due to biases in the downwelling long-wave radiation and the lack of complex surface structures, like leads. The large eddy resolving turbulence closure yielded a better representation of the lower boundary layer under strongly stable stratification than the non-eddy-resolving turbulence closure. Furthermore, the integration of leads into the sea-ice surface reduced the overestimation of the sensible heat flux for different weather conditions. The results of this work help to better understand boundary layer processes in the central Arctic during the polar night. High-resolving mesoscale simulations are able to represent temporally and spatially small interactions and help to further develop parameterizations also for the application in regional and global models.

Description / Table of Contents: The Arctic is the hot spot of the ongoing, global climate change. Over the last decades, near-surface temperatures in the Arctic have been rising almost four times faster than on global average. This amplified warming of the Arctic and the associated rapid changes of its environment are largely influenced by interactions between individual components of the Arctic climate system. On daily to weekly time scales, storms can have major impacts on the Arctic sea-ice cover and are thus an important part of these interactions within the Arctic climate. The sea-ice impacts of storms are related to high wind speeds, which enhance the drift and deformation of sea ice, as well as to changes in the surface energy budget in association with air mass advection, which impact the seasonal sea-ice growth and melt. The occurrence of storms in the Arctic is typically associated with the passage of transient cyclones. Even though the above described mechanisms how storms/cyclones impact the Arctic sea ice are in principal known, there is a lack of statistical quantification of these effects. In accordance with that, the overarching objective of this thesis is to statistically quantify cyclone impacts on sea-ice concentration (SIC) in the Atlantic Arctic Ocean over the last four decades. In order to further advance the understanding of the related mechanisms, an additional objective is to separate dynamic and thermodynamic cyclone impacts on sea ice and assess their relative importance. Finally, this thesis aims to quantify recent changes in cyclone impacts on SIC. These research objectives are tackled utilizing various data sets, including atmospheric and oceanic reanalysis data as well as a coupled model simulation and a cyclone tracking algorithm. Results from this thesis demonstrate that cyclones are significantly impacting SIC in the Atlantic Arctic Ocean from autumn to spring, while there are mostly no significant impacts in summer. The strength and the sign (SIC decreasing or SIC increasing) of the cyclone impacts strongly depends on the considered daily time scale and the region of the Atlantic Arctic Ocean. Specifically, an initial decrease in SIC (day -3 to day 0 relative to the cyclone) is found in the Greenland, Barents and Kara Seas, while SIC increases following cyclones (day 0 to day 5 relative to the cyclone) are mostly limited to the Barents and Kara Seas. For the cold season, this results in a pronounced regional difference between overall (day -3 to day 5 relative to the cyclone) SIC-decreasing cyclone impacts in the Greenland Sea and overall SIC-increasing cyclone impacts in the Barents and Kara Seas. A cyclone case study based on a coupled model simulation indicates that both dynamic and thermodynamic mechanisms contribute to cyclone impacts on sea ice in winter. A typical pattern consisting of an initial dominance of dynamic sea-ice changes followed by enhanced thermodynamic ice growth after the cyclone passage was found. This enhanced ice growth after the cyclone passage most likely also explains the (statistical) overall SIC-increasing effects of cyclones in the Barents and Kara Seas in the cold season. Significant changes in cyclone impacts on SIC over the last four decades have emerged throughout the year. These recent changes are strongly varying from region to region and month to month. The strongest trends in cyclone impacts on SIC are found in autumn in the Barents and Kara Seas. Here, the magnitude of destructive cyclone impacts on SIC has approximately doubled over the last four decades. The SIC-increasing effects following the cyclone passage have particularly weakened in the Barents Sea in autumn. As a consequence, previously existing overall SIC-increasing cyclone impacts in this region in autumn have recently disappeared. Generally, results from this thesis show that changes in the state of the sea-ice cover (decrease in mean sea-ice concentration and thickness) and near-surface air temperature are most important for changed cyclone impacts on SIC, while changes in cyclone properties (i.e. intensity) do not play a significant role.

Description / Table of Contents: The arctic is warming 2 – 4 times faster than the global average, resulting in a strong feedback on northern ecosystems such as boreal forests, which cover a vast area of the high northern latitudes. With ongoing global warming, the treeline subsequently migrates northwards into tundra areas. The consequences of turning ecosystems are complex: on the one hand, boreal forests are storing large amounts of global terrestrial carbon and act as a carbon sink, dragging carbon dioxide out of the global carbon cycle, suggesting an enhanced carbon uptake with increased tree cover. On the other hand, with the establishment of trees, the albedo effect of tundra decreases, leading to enhanced soil warming. Meanwhile, permafrost thaws, releasing large amounts of previously stored carbon into the atmosphere. So far, mainly vegetation dynamics have been assessed when studying the impact of warming onto ecosystems. Most land plants are living in close symbiosis with bacterial and fungal communities, sustaining their growth in nutrient poor habitats. However, the impact of climate change on these subsoil communities alongside changing vegetation cover remains poorly understood. Therefore, a better understanding of soil community dynamics on multi millennial timescales is inevitable when addressing the development of entire ecosystems. Unravelling long-term cross-kingdom dependencies between plant, fungi, and bacteria is not only a milestone for the assessment of warming on boreal ecosystems. On top, it also is the basis for agriculture strategies to sustain society with sufficient food in a future warming world. The first objective of this thesis was to assess ancient DNA as a proxy for reconstructing the soil microbiome (Manuscripts I, II, III, IV). Research findings across these projects enable a comprehensive new insight into the relationships of soil microorganisms to the surrounding vegetation. First, this was achieved by establishing (Manuscript I) and applying (Manuscript II) a primer pair for the selective amplification of ancient fungal DNA from lake sediment samples with the metabarcoding approach. To assess fungal and plant co-variation, the selected primer combination (ITS67, 5.8S) amplifying the ITS1 region was applied on samples from five boreal and arctic lakes. The obtained data showed that the establishment of fungal communities is impacted by warming as the functional ecological groups are shifting. Yeast and saprotroph dominance during the Late Glacial declined with warming, while the abundance of mycorrhizae and parasites increased with warming. The overall species richness was also alternating. The results were compared to shotgun sequencing data reconstructing fungi and bacteria (Manuscripts III, IV), yielding overall comparable results to the metabarcoding approach. Nonetheless, the comparison also pointed out a bias in the metabarcoding, potentially due to varying ITS lengths or copy numbers per genome. The second objective was to trace fungus-plant interaction changes over time (Manuscripts II, III). To address this, metabarcoding targeting the ITS1 region for fungi and the chloroplast P6 loop for plants for the selective DNA amplification was applied (Manuscript II). Further, shotgun sequencing data was compared to the metabarcoding results (Manuscript III). Overall, the results between the metabarcoding and the shotgun approaches were comparable, though a bias in the metabarcoding was assumed. We demonstrated that fungal shifts were coinciding with changes in the vegetation. Yeast and lichen were mainly dominant during the Late Glacial with tundra vegetation, while warming in the Holocene lead to the expansion of boreal forests with increasing mycorrhizae and parasite abundance. Aside, we highlighted that Pinaceae establishment is dependent on mycorrhizal fungi such as Suillineae, Inocybaceae, or Hyaloscypha species also on long-term scales. The third objective of the thesis was to assess soil community development on a temporal gradient (Manuscripts III, IV). Shotgun sequencing was applied on sediment samples from the northern Siberian lake Lama and the soil microbial community dynamics compared to ecosystem turnover. Alongside, podzolization processes from basaltic bedrock were recovered (Manuscript III). Additionally, the recovered soil microbiome was compared to shotgun data from granite and sandstone catchments (Manuscript IV, Appendix). We assessed if the establishment of the soil microbiome is dependent on the plant taxon and as such comparable between multiple geographic locations or if the community establishment is driven by abiotic soil properties and as such the bedrock area. We showed that the development of soil communities is to a great extent driven by the vegetation changes and temperature variation, while time only plays a minor role. The analyses showed general ecological similarities especially between the granite and basalt locations, while the microbiome on species-level was rather site-specific. A greater number of correlated soil taxa was detected for deep-rooting boreal taxa in comparison to grasses with shallower roots. Additionally, differences between herbaceous taxa of the late Glacial compared to taxa of the Holocene were revealed. With this thesis, I demonstrate the necessity to investigate subsoil community dynamics on millennial time scales as it enables further understanding of long-term ecosystem as well as soil development processes and such plant establishment. Further, I trace long-term processes leading to podzolization which supports the development of applied carbon capture strategies under future global warming.

Description / Table of Contents: Der exklusive Fotoband zur Jahrhundertexpedition in die Arktis. Im September 2019 legte die Polarstern in Richtung Arktis ab - an Bord das internationale MOSAiC-Forscherteam, das die Auswirkungen des Klimawandels auf das ewige Eis erkundet. Chronologisch aufgebaut dokumentiert der bildgewaltige Band in bisher ungesehenen Fotografien von Esther Horvath Leben und Arbeiten während der einjährigen Reise unter den extremen Bedingungen am Nordpol. Begleitet von kenntnisreichen Essays und Textbeiträgen von Experten, Wissenschaftlern und Expeditionsteilnehmern ist der Band ein eindrucksvolles Zeugnis der wohl größten klimatischen Herausforderung unserer Zeit und bietet Einblicke in dieses einmalige Forschungsprojekt sowie die spektakuläre, schützenswerte Polarlandschaft.

Description / Table of Contents: Noch nie haben Forschende das Meereis der Arktis so umfassend untersuchen können, wie auf der internationalen MOSAiC-Expedition des Forschungseisbrechers Polarstern. Ein Jahr lang ist das Schiff mit dem Eis durch die zentrale Arktis getrieben; ein Jahr lang haben die Männer und Frauen das Eis mithilfe modernster Technik unter die Lupe genommen. Welche Herausforderungen es dabei zu meistern galt und was sie herausgefunden haben im polaren Hotspot des Klimawandels, erzählen sie in zehn DriftStories, die dieser Band vereint. Faszinierende Arktisforschung zum Anfassen – präsentiert von meereisportal.de.

Description / Table of Contents: Never before have researchers had the chance to explore the Arctic sea ice as comprehensively as on the international MOSAiC expedition. For an entire year, the research icebreaker Polarstern drifted through the Central Arctic with the sea ice; for an entire year, the men and women of the expedition painstakingly investigated the ice with the aid of cutting-edge technologies. In the ten DriftStories gathered here, they share the challenges they had to overcome, and the discoveries they made in this polar hotspot of climate change: fascinating Arctic research at your fingertips - presented by meereisportal.de.

Description / Table of Contents: Stratospheric variability is one of the main potential sources for sub-seasonal to seasonal predictability in mid-latitudes in winter. Stratospheric pathways play an important role for long-range teleconnections between tropical phenomena, such as the quasi-biennial oscillation (QBO) and El Niño-Southern Oscillation (ENSO), and the mid-latitudes on the one hand, and linkages between Arctic climate change and the mid-latitudes on the other hand. In order to move forward in the field of extratropical seasonal predictions, it is essential that an atmospheric model is able to realistically simulate the stratospheric circulation and variability. The numerical weather prediction (NWP) configuration of the ICOsahedral Non-hydrostatic atmosphere model ICON is currently being used by the German Meteorological Service for the regular weather forecast, and is intended to produce seasonal predictions in future. This thesis represents the first extensive evaluation of Northern Hemisphere stratospheric winter circulation in ICON-NWP by analysing a ...

Description / Table of Contents: Anthropogenic climate change constitutes one of the main global crises in the 21st century. It manifests itself distinctly in global warming and its effects. Forests play an essential role in mitigating the effects of climate change, improving our knowledge of the distribution and changes of terrestrial carbon stocks is vital to mitigate its consequences. Therefore, remote sensing is recommended as one of the tools to ensure systematic and operational forest monitoring. Forests in the Russian Federation are of particular importance as it is the most forested country in the world and at the same time, it is the country with the highest uncertainty when calculating global carbon stocks. Remote sensing is recommended as one of the tools to ensure systematic and operational forest monitoring. It can acquire data over large areas with a high repetition rate and at a relatively low cost. In particular, microwave sensors are recommended as they can provide weather and sun independent, systematic observations with high temporal frequency. The main goal of this cumulative dissertation was to develop methods using new algorithms for estimating parameters for boreal forests from remote sensing data acquired with Synthetic Aperture Radar (SAR). Using the SAR data acquired by the sensor with the longest wavelength available at the moment of writing this dissertation in space, the L-band, methods for estimating the above-ground forest biomass were developed. For this purpose, algorithms for machine learning (ML) were applied and validated. These methods were chosen because they are recommended for large data sets and an incomplete theoretical understanding of processes, e.g., the interaction between the forest and the radar signal, and are relatively new in forest monitoring studies. In addition, efforts have been made to establish improved mapping of large-scale forest cover change

Description / Table of Contents: This book provides a cross-disciplinary overview of permafrost and the carbon cycle by providing an introduction into the geographical distribution of permafrost, with a focus on the distribution of permafrost and its soil carbon reservoirs. The chapters explain the basic physical properties and processes of permafrost soils: ice, mineral and organic components, and how these interact with climate, vegetation and geomorphological processes. In particular, the book covers the role of the large quantities of ice in many permafrost soils which are crucial to understanding carbon cycle processes. An explanation is given on how permafrost becomes loaded with ice and carbon. Gas hydrates are also introduced. Structures and processes formed by the intense freeze-thaw action in the active layer are considered (e.g. ice wedging, cryoturbation), and the processes that occur as the permafrost thaws, (pond and lake formation, erosion). The book introduces soil carbon accumulation and decomposition mechanisms and how these are modified in a permafrost environment. A separate chapter deals with deep permafrost carbon, gas reservoirs and recently discovered methane emission phenomena from regions such as Northwest Siberia and the Siberian yedoma permafrost.

Description / Table of Contents: Die Hochgebirge haben eine große Bedeutung für das globale Klima, die Wasserversorgung und die Biosphäre. So ist die besonders starke Ausprägung des Amazonas-Regenwalds den Anden zu verdanken. Sie verhindern den Durchzug der aus dem Atlantik mit viel Luftfeuchtigkeit kommenden Wolken. Dadurch erhält das Amazonas-Gebiet im Jahresdurchschnitt über 2.000 mm Regen, was die Grundlage für die intensive Bewaldung ist. Obwohl die Gebirge global nur ca. 12% der Landfläche bedecken, beherbergen Hochgebirge rund die Hälfte aller Säugetierarten und 74% aller endemischen Vogelarten (ohne Inselarten). 21 der 34 globalen Biodiversitätshotspots befinden sich in Hochgebirgen. In den Gebirgen entstehen aufgrund von höheren Niederschlägen wichtige Wasserressourcen auch für die angrenzenden Tiefländer. Trotz der für den Menschen oft erschwerten Zugänglichkeit sind Hochgebirge und Hoch-Plateaus, besonders in tropischen Regionen, Orte dichter Besiedlung und sogar von Hochkulturen. Die Folgen des Klimawandels sind in den Hochgebirgen besonders deutlich. So war die Erwärmung in den vergangenen Jahrzehnten dort höher als in den Flachländern. Die Gletscher schrumpfen in fast allen Gebirgen, insbesondere in den letzten Jahrzehnten. Auf den jetzt eisfreien Flächen siedeln sich schon nach wenigen Jahren neue Pflanzengemeinschaften an. In den Alpen hat das Eisvolumen seit 1850 schon um mehr als zwei Drittel abgenommen. Das entspricht allein seit 1997 einem Süßwasserverlust von etwa dem 14fachen Volumen des Bodensees. Insgesamt sind die Klimaänderungen in den Gebirgsregionen gravierender als im Flachland. Mit der Zunahme der Starkregen und dem Rückgang des Permafrosts nimmt die Gefahr von Erdrutschen zu, und manche Gletscher wurden instabil. Im Mittel haben sich die Temperaturen im Gebirgspermafrost in einem Jahrzehnt von 2007 bis 2016 um etwa 0,2°C erhöht. Die Schneedeckendauer nahm in den letzten Jahrzehnten kontinuierlich ab; die Herausforderungen für den Wintertourismus werden zusehends größer.

Description / Table of Contents: Der zentralasiatische Naturraum, wie er sich uns heute präsentiert, ist das Ergebnis eines Zusammenwirkens vieler verschiedener Faktoren über Jahrmillionen hinweg. Im aktuellen Kontext des Klimawandels zeigt sich jedoch, wie stark sich Stoffflüsse auch kurzfristig ändern und dabei das Gesicht der Landschaft verwandeln können. Die Gobi-Wüste in der Inneren Mongolei (China), als Teil der gleichnamigen Trockenregionen Nordwestchinas, ist aufgrund der Ausgestaltung ihrer landschaftsprägenden Elemente sowie ihrer Landschaftsdynamik, im Zusammenhang mit der Lage zum Tibet-Plateau, in den Fokus der klimageschichtlichen Grundlagenforschung gerückt. Als großes Langzeitarchiv unterschiedlichster fluvialer, lakustriner und äolischer Sedimente stellt sie eine bedeutende Lokalität zur Rekonstruktion von lokalen und regionalen Stoffflüssen dar.. Andererseits ist die Gobi-Wüste zugleich auch eine bedeutende Quelle für den überregionalen Staubtransport, da sie aufgrund der klimatischen Bedingungen insbesondere der Erosion durch Ausblasung preisgegeben wird. Vor diesem Hintergrund erfolgten zwischen 2011 und 2014, im Rahmen des BMBF-Verbundprogramms WTZ Zentralasien – Monsundynamik & Geoökosysteme (Förderkennzeichen 03G0814), mehrere deutsch-chinesische Expeditionen in das Ejina-Becken (Innere Mongolei) und das Qilian Shan-Vorland. Im Zuge dieser Expeditionen wurden für eine Bestimmung potenzieller Sedimentquellen erstmals zahlreiche Oberflächenproben aus dem gesamten Einzugsgebiet des Heihe (schwarzer Fluss) gesammelt. Zudem wurden mit zwei Bohrungen im inneren des Ejina-Beckens, ergänzende Sedimentbohrkerne zum bestehenden Bohrkern D100 (siehe Wünnemann (2005)) abgeteuft, um weit reichende, ergänzende Informationen zur Landschaftsgeschichte und zum überregionalen Sedimenttransfer zu erhalten. Gegenstand und Ziel der vorliegenden Doktorarbeit ist die sedimentologisch-mineralogische Charakterisierung des Untersuchungsgebietes in Bezug auf potenzielle Sedimentquellen und Stoffflüsse des Ejina-Beckens sowie die Rekonstruktion der Ablagerungsgeschichte eines dort erbohrten, 19m langen Sedimentbohrkerns (GN100). Schwerpunkt ist hierbei die Klärung der Sedimentherkunft innerhalb des Bohrkerns sowie die Ausweisung von Herkunftssignalen und möglichen Sedimentquellen bzw. Sedimenttransportpfaden. Die methodische Herangehensweise basiert auf einem Multi-Proxy-Ansatz zur Charakterisierung der klastischen Sedimentfazies anhand von Geländebeobachtungen, lithologisch-granulometrischen und mineralogisch-geochemischen Analysen sowie statistischen Verfahren. Für die mineralogischen Untersuchungen der Sedimente wurde eine neue, rasterelektronenmikroskopische Methode zur automatisierten Partikelanalyse genutzt und den traditionellen Methoden gegenübergestellt. Die synoptische Betrachtung der granulometrischen, geochemischen und mineralogischen Befunde der Oberflächensedimente ergibt für das Untersuchungsgebiet ein logisches Kaskadenmodell mit immer wiederkehrenden Prozessbereichen und ähnlichen Prozesssignalen. Die umfangreichen granulometrischen Analysen deuten dabei auf abnehmende Korngrößen mit zunehmender Entfernung vom Qilian Shan hin und ermöglichen die Identifizierung von vier texturellen Signalen: den fluvialen Sanden, den Dünensanden, den Stillwassersedimenten und Stäuben. Diese Ergebnisse können als Interpretationsgrundlage für die Korngrößenanalysen des Bohrkerns genutzt werden. Somit ist es möglich, die Ablagerungsgeschichte der Bohrkernsedimente zu rekonstruieren und in Verbindung mit eigenen und literaturbasierten Datierungen in einen Gesamtkontext einzuhängen. Für das Untersuchungsgebiet werden somit vier Ablagerungsphasen ausgewiesen, die bis in die Zeit des letzten glazialen Maximums (LGM) zurückreichen. Während dieser Ablagerungsphasen kam es im Zuge unterschiedlicher Aktivitäts- und Stabilitätsphasen zu einer kontinuierlichen Progradation und Überprägung des Schwemmfächers. Eine besonders aktive Phase kann zwischen 8 ka und 4 ka BP festgestellt werden, während der es aufgrund zunehmender fluvialer Aktivitäten zu einer deutlich verstärkten Schwemmfächerdynamik gekommen zu sein scheint. In den Abschnitten davor und danach waren es vor allem äolische Prozesse, die zu einer Überprägung des Schwemmfächers geführt haben. Hinsichtlich der mineralogischen Herkunftssignale gibt es eine große Variabilität. Dies spiegelt die enorme Heterogenität der Geologie des Untersuchungsgebietes wider, wodurch die räumlichen Signale nicht sehr stark ausgeprägt sind. Dennoch, können für das Einzugsgebiet drei größere Bereiche deklariert werden, die als Herkunftsgebiet in Frage kommen. Das östliche Qilian Shan Vorland zeichnet sich dabei durch deutlich höhere Chloritgehalte als primäre Quelle für die Sedimente im Ejina-Becken aus. Sie unterscheiden sich insbesondere durch stark divergierende Chloritgehalte in der Tonmineral- und Gesamtmineralfraktion, was das östliche Qilian Shan Vorland als primäre Quelle für die Sedimente im Ejina-Becken auszeichnet. Dies steht in Zusammenhang mit den Grünschiefern, Ophioliten und Serpentiniten in diesem Bereich. Geochemisch deutet vor allem das Cr/Rb-Verhältnis eine große Variabilität innerhalb des Einzugsgebietes an. Auch hier ist es das östliche Vorland, welches aufgrund seines hohen Anteils an mafischen Gesteinen reich an Chromiten und Spinellen ist und sich somit vom restlichen Untersuchungsgebiet abhebt. Die zeitliche aber auch die generelle Variabilität der Sedimentherkunft lässt sich in den Bohrkernsedimenten nicht so deutlich nachzeichnen. Die mineralogisch-sedimentologischen Eigenschaften der erbohrten klastischen Sedimente zeugen zwar von zwischenzeitlichen Änderungen bei der Sedimentherkunft, diese sind jedoch nicht so deutlich ausgeprägt, wie es die Quellsignale in den Oberflächensedimenten vermuten lassen. Ein Grund dafür scheint die starke Vermischung unterschiedlichster Sedimente während des Transportes zu sein. Die Kombination der Korngrößenergebnisse mit den Befunden der Gesamt- und Schwermineralogie deuten darauf hin, dass es zwischenzeitlich eine Phase mit überwiegend äolischen Prozessen gegeben hat, die mit einem Sedimenteintrag aus dem westlichen Bei Shan in Verbindung stehen. Neben der Zunahme ultrastabiler Schwerminerale wie Zirkon und Granat und der Abnahme opaker Schwerminerale, weisen vor allem die heutigen Verhältnisse darauf hin. Der Vergleich der traditionellen Schwermineralanalyse mit der Computer-Controlled-Scanning-Electron-Microscopy (kurz: CCSEM), die eine automatisierte Partikelauswertung der Proben ermöglicht, zeigt den deutlichen Vorteil der modernen Analysemethode. Neben einem zeitlichen Vorteil, den man durch die automatisierte Abarbeitung der vorbereiteten Proben erlangen kann, steht vor allem die deutlich größere statistische Signifikanz des Ergebnisses im Vordergrund. Zudem können mit dieser Methode auch chemische Varietäten einiger Schwerminerale bestimmt werden, die eine noch feinere Klassifizierung und sicherere Aussagen zu einer möglichen Sedimentherkunft ermöglichen. Damit ergeben sich außerdem verbesserte Aussagen zu Zusammensetzungen und Entstehungsprozessen der abgelagerten Sedimente. Die Studie verdeutlicht, dass die Sedimentherkunft innerhalb des Untersuchungsgebietes sowie die ablaufenden Prozesse zum Teil stark von lokalen Gegebenheiten abhängen. Die Heterogenität der Geologie und die Größe des Einzugsgebietes sowie die daraus resultierende Komplexität der Sedimentgenese, machen exakte Zuordnungen zu klar definierten Sedimentquellen sehr schwer. Dennoch zeigen die Ergebnisse, dass die Sedimentzufuhr in das Ejina-Becken in erster Linie durch fluviale klastische Sedimente des Heihe aus dem Qilian Shan erfolgt sein muss. Die Untersuchungsergebnisse zeigen jedoch ebenso die Notwendigkeit einer ergänzenden Bearbeitung angrenzender Untersuchungsgebiete, wie beispielsweise den Gobi-Altai im Norden oder den Beishan im Westen, sowie die Verdichtung der Oberflächenbeprobung zur feineren Auflösung von lokalen Sedimentquellen.

Description / Table of Contents: In the Anthropocene, the thawing of frozen earth due to global warming has drawn worldwide attention to permafrost. Contemporary scientists define permafrost as ground that maintains a negative temperature for at least two years. But where did this particular conception of permafrost originate, and what alternatives existed? The Life of Permafrost provides an intellectual history of permafrost, placing the phenomenon squarely in the political, social, and material context of Russian and Soviet science. Pey-Yi Chu shows that understandings of frozen earth were shaped by two key experiences in the Russian Empire and the Soviet Union. On one hand, the colonization and industrialization of Siberia nourished an engineering perspective on frozen earth that viewed the phenomenon as an aggregate physical structure: ground. On the other, a Russian and Soviet tradition of systems thinking encouraged approaching frozen earth as a process, condition, and space tied to planetary exchanges of energy and matter. Aided by the US militarization of the Arctic during the Cold War, the engineering view of frozen earth as an obstacle to construction became dominant. The Life of Permafrost tells the fascinating story of how permafrost came to acquire life as Russian and Soviet scientists studied, named, and defined it.

Description / Table of Contents: Die MOSAiC-Expedition verschiebt die Grenzen des Machbaren und markiert einen historischen Meilenstein der Polarforschung. In den Fußstapfen von Fridtjof Nansens bahnrechender Pionierleistung in den Jahren 1893 bis 1896 mit seinem hölzernen Segelschiff »Fram« bringt sie erstmals einen modernen Forschungseisbrecher im Winter in die direkte Umgebung des Nordpols. 20 Nationen haben sich zusammengetan, um die Geheimnisse des dramatischen Klimawandels der Arktis zu entschlüsseln. Untertützt wird das Flaggschiff der Expedition, der deutsche Forschungseisbrecher »Polarstern«, von sechs weiteren Schiffen und Eisbrechern, Flugzeugen und Helikoptern. Insgesamt fünfhundert Menschen nehmen an den verschiedenen Phasen der Expedition teil. Markus Rex, Kopf des Vorhabens und Expeditionsleiter, berichtet anschaulich vom oft genug dramatischen Verlauf dieser Expedition, aber auch von überwältigend faszinierenden Eindrücken aus der Arktis während der langen winterlichen Polarnacht und während des sommerlichen Polartags. Und er beschreibt die unvorstellbaren Herausforderungen, denen sich die Expeditionsteilnehmer eingefroren im polaren Eis gestellt haben - immer geleitet von dem Ziel, Licht in die Prozesse des globalen Klimawandels zu bringen, der nirgends so auseprägt ist wie in der Arktis.

Description / Table of Contents: This thesis investigates how the permafrost microbiota responds to global warming. In detail, the constraints behind methane production in thawing permafrost were linked to methanogenic activity, abundance and composition. Furthermore, this thesis offers new insights into microbial adaptions to the changing environmental conditions during global warming. This was assesed by investigating the potential ecological relevant functions encoded by plasmid DNA within the permafrost microbiota. Permafrost of both interglacial and glacial origin spanning the Holocene to the late Pleistocene, including Eemian, were studied during long-term thaw incubations. Furthermore, several permafrost cores of different stratigraphy, soil type and vegetation cover were used to target the main constraints behind methane production during short-term thaw simulations. Short- and long-term incubations simulating thaw with and without the addition of substrate were combined with activity measurements, amplicon and metagenomic sequencing of permanently frozen and seasonally thawed active layer. Combined, it allowed to address the following questions. i) What constraints methane production when permafrost thaws and how is this linked to methanogenic activity, abundance and composition? ii) How does the methanogenic community composition change during long-term thawing conditions? iii) Which potential ecological relevant functions are encoded by plasmid DNA in active layer soils? The major outcomes of this thesis are as follows. i) Methane production from permafrost after long-term thaw simulation was found to be constrained mainly by the abundance of methanogens and the archaeal community composition. Deposits formed during periods of warmer temperatures and increased precipitation, (here represented by deposits from the Late Pleistocene of both interstadial and interglacial periods) were found to respond strongest to thawing conditions and to contain an archaeal community dominated by methanogenic archaea (40% and 100% of all detected archaea). Methanogenic population size and carbon density were identified as main predictors for potential methane production in thawing permafrost in short-term incubations when substrate was sufficiently available. ii) Besides determining the methanogenic activity after long-term thaw, the paleoenvironmental conditions were also found to influence the response of the methanogenic community composition. Substantial shifts within methanogenic community structure and a drop in diversity were observed in deposits formed during warmer periods, but not in deposits from stadials, when colder and drier conditions occurred. Overall, a shift towards a dominance of hydrogenotrophic methanogens was observed in all samples, except for the oldest interglacial deposits from the Eemian, which displayed a potential dominance of acetoclastic methanogens. The Eemian, which is discussed to serve as an analogue to current climate conditions, contained highly active methanogenic communities. However, all potential limitation of methane production after permafrost thaw, it means methanogenic community structure, methanogenic population size, and substrate pool might be overcome after permafrost had thawed on the long-term. iii) Enrichments with soil from the seasonally thawed active layer revealed that its plasmid DNA (‘metaplasmidome’) carries stress-response genes. In particular it encoded antibiotic resistance genes, heavy metal resistance genes, cold shock proteins and genes encoding UV-protection. Those are functions that are directly involved in the adaptation of microbial communities to stresses in polar environments. It was further found that metaplasmidomes from the Siberian active layer originate mainly from Gammaproteobacteria. By applying enrichment cultures followed by plasmid DNA extraction it was possible to obtain a higher average contigs length and significantly higher recovery of plasmid sequences than from extracting plasmid sequences from metagenomes. The approach of analyzing ‘metaplasmidomes’ established in this thesis is therefore suitable for studying the ecological role of plasmids in polar environments in general. This thesis emphasizes that including microbial community dynamics have the potential to improve permafrost-carbon projections. Microbially mediated methane release from permafrost environments may significantly impact future climate change. This thesis identified drivers of methanogenic composition, abundance and activity in thawing permafrost landscapes. Finally, this thesis underlines the importance to study how the current warming Arctic affects microbial communities in order to gain more insight into microbial response and adaptation strategies.

Description / Table of Contents: The first comprehensive, state-of-the-art introduction to the fast-evolving topic of in-situ produced cosmogenic nuclides, for graduate students and practitioners.

Description / Table of Contents: Measurement Methods in Atmospheric Sciences provides a comprehensive overview of in-situ and remote sensing measurement techniques for probing the Earth's atmosphere. The methods presented in this book span the entire range from classical meteorology via atmospheric chemistry and micrometeorological flux determination to Earth observation from space. Standard instruments for meteorological and air quality monitoring methods, as well as specialized instrumentation predominantly used in scientific experiments, are covered. The presented techniques run from simple mechanical sensors to highly sophisticated electronic devices. Special emphasis is placed on the rapidly evolving field of remote sensing techniques. Here, active ground-based remote sending techniques such as SODAR and LIDAR find a detailed coverage. The book conveys the basic principles of the various observational and monitoring methods, enabling the user to identify the most appropriate method. An introductory chapter covers general principles (e.g. inversion of measured data, available platforms, statistical properties of data, data acquisition). Later chapters each treat methods for measuring a specific property (e.g. humidity, wind speed, wind direction). Long chapters provide an introductory tabular list of the methods treated. More than 100 figures and 400 references, mostly to the recent scientific literature, aid the reader in reading up on the details of the various methods at hand. Recommendations at the end of each major chapter provide additional hints on the use of some instruments in order to facilitate the selection of the proper instrument for a successful measurement. A large number of national and international standards, providing precise guidelines for measuring and acquiring reliable, reproducible and comparable data sets are listed in the appendix. A dedicated index allows easy access to this valuable information. The book is of interest to undergraduate and graduate students in meteorology, physical geography, ecology, environmental sciences and related disciplines as well as to scientists in the process of planning atmospheric measurements in field campaigns or working with data already acquired. Practitioners in environmental agencies and similar institutions will benefit from instrument descriptions and the extended lists in the appendix.

Description / Table of Contents: Demonstrating the breadth and depth of growth in the field since the publication of the popular first edition, Image Analysis, Classification and Change Detection in Remote Sensing, with Algorithms for ENVI/IDL, Second Edition has been updated and expanded to keep pace with the latest versions of the ENVI software environment. Effectively interweaving theory, algorithms, and computer codes, the text supplies an accessible introduction to the techniques used in the processing of remotely sensed imagery.

Description / Table of Contents: This book covers a round-up of environmental changes in Siberia with a focus on the terrestrial biosphere but also discussing climate and atmosphere and the hydrolofical cycle. It concludes with a discussion of information system approaches that are being developed to safeguard and make accessible spatial and temporal data for environmental studies.

Description / Table of Contents: This much revised and expanded edition provides a valuable and detailed summary of the many uses of diatoms in a wide range of applications in the environmental and earth sciences. Particular emphasis is placed on the use of diatoms in analyzing ecological problems related to climate change, acidification, eutrophication, and other pollution issues. The chapters are divided into sections for easy reference, with separate sections covering indicators in different aquatic environments. A final section explores diatom use in other fields of study such as forensics, oil and gas exploration, nanotechnology, and archeology. Sixteen new chapters have been added since the first edition including introductory chapters on diatom biology and the numerical approaches used by diatomists. The extensive glossary has also been expanded and now includes over 1000 detailed entries, which will help non-specialists to use the book effectively

Description / Table of Contents: The Global Carbon Cycle is a short introduction to this essential geochemical driver of the earth's climate system, written by one of the world's leading climate-science experts. In this one-of-a-kind primer, David Archer engages readers in clear and simple terms about the many ways the global carbon cycle is woven into our climate system. He begins with a concise overview of the subject, and then looks at the carbon cycle on three different time scales, describing how the cycle interacts with climate in very distinct ways in each. On million-year time scales, feedbacks in the carbon cycle stabilize earth's climate and oxygen concentrations. Archer explains how on hundred-thousand-year glacial / interglacial time scales, the carbon cycle in the ocean amplifies climate change, and how, on the human time scale of decades, the carbon cycle has been dampening climate change by absorbing fossil-fuel carbon dioxide into the oceans and land biosphere. A central question of the book is whether the carbon cycle could once again act to amplify climate change in centuries to come, for example through melting permafrost peatlands and methane hydrates. The Global Carbon Cycle features a glossary of terms, suggestions for further reading, and explanations of equations, as well as a forward-looking discussion of open questions about the global carbon cycle.

Description / Table of Contents: This chapter is the ninth to be released in U.S. Geological Survey Professional Paper 1386, Satellite Image Atlas of Glaciers of the World, a series of 11 chapters. In each of the geographic area chapters, remotely sensed images, primarily from the Landsat 1, 2, and 3 series of spacecraft, are used to analyze the specific glacierized region of our planet under consideration and to monitor glacier changes. Landsat images, acquired primarily during the middle to late 1970s and early 1980s, were used by an international team of glaciologists and other scientists to study various geographic regions and (or) to discuss related glaciological topics. In each glacierized geographic region, the present areal distribution of glaciers is compared, wherever possible, with historical information about their past extent. The atlas provides an accurate regional inventory of the areal extent of glacier ice on our planet during the 1970s as part of a growing international scientific effort to measure global environmental change on the Earth's surface.The chapter is divided into seven geographic parts and one topical part: Glaciers of the Former Soviet Union (F-1), Glaciers of China (F-2), Glaciers of Afghanistan (F-3), Glaciers of Pakistan (F-4), Glaciers of India (F-5), Glaciers of Nepal (F-6), Glaciers of Bhutan (F-7), and the Paleoenvironmental Record Preserved in Middle-Latitude, High-Mountain Glaciers (F-8). Each geographic section describes the glacier extent during the 1970s and 1980s, the benchmark time period (1972-1981) of this volume, but has been updated to include more recent information.

Description / Table of Contents: Glaciers & Glaciation is the classic textbook for all students of glaciation. Stimulating and accessible, it has established a reputation as a comprehensive and essential resource. In this new edition, the text, references and illustrations have been thoroughly updated to provide a state-of-the-art overview of the nature, origin and behaviour of glaciers and the geological and geomorphological evidence for their past history on earth. The first part of the book investigates the processes involved in forming glacier ice, the natureof glacier-climate relationships, the mechanisms of glacier flow and the interactions of glaciers with other natural systems such as rivers, lakes and oceans. In the second part, the emphasis moves to landforms and sediment, the interpretation of the earth's glacial legacy and the reconstruction of glacial depositional environments and palaeoglaciology.

Description / Table of Contents: Since the publication of "Spectral Methods in Fluid Dynamics", spectral methods, particularly in their multidomain version, have become firmly established as a mainstream tool for scientific and engineering computation. While retaining the tight integration between the theoretical and practical aspects of spectral methods that was the hallmark of the earlier book, Canuto et al. now incorporate the many improvements in the algorithms and the theory of spectral methods that have been made since 1988. The initial treatment Fundamentals in Single Domains discusses the fundamentals of the approximation of solutions to ordinary and partial differential equations on single domains by expansions in smooth, global basis functions. The first half of the book provides the algorithmic details of orthogonal expansions, transform methods, spectral discretization of differential equations plus their boundary conditions, and solution of the discretized equations by direct and iterative methods. The second half furnishes a comprehensive discussion of the mathematical theory of spectral methods on single domains, including approximation theory, stability and convergence, and illustrative applications of the theory to model boundary-value problems. Both the algorithmic and theoretical discussions cover spectral methods on tensor-product domains, triangles and tetrahedra. All chapters are enhanced with material on the Galerkin with numerical integration version of spectral methods. The discussion of direct and iterative solution methods is greatly expanded as are the set of numerical examples that illustrate the key properties of the various types of spectral approximations and the solution algorithms. A companion book "Evolution to Complex Geometries and Applications to Fluid Dynamics" contains an extensive survey of the essential algorithmic and theoretical aspects of spectral methods for complex geometries and provides detailed discussions of spectral algorithms for fluid dynamics in simple and complex geometries.

Description / Table of Contents: While researching for another film, filmmakers Tom Radford and Peter Raymont came across the story of Nugliak, an Inuvialuit man born just before the end of the 19th century who observed and wrote of the changes that occurred in the north during his lifetime on Herschel Island. Radford's film loosely follows the book, touching on much the same subjects, but using Nugliak's descendents as a link to the present.

Description / Table of Contents: It is easy to overlook Herschel Island - a tiny speck of land just off the Yukon coast - where the Inuvialuit hunter Nuligak once followed the great journeys of caribou, polar bears, and whales. The island lays silently on the margins of geography, entrapped in the footnotes of history, a forgotten place frozen in time. And yet just over a century ago Herschel Island was a frontier boomtown, branded "the Sodom of the Arctic" by some visitors at the time. A place cohabited by whalers, Inuit, missionaries, and police; a place of contact and conflict; a place where worlds collided and lives were changed forever. It was on Herschel Island that a young Inucialuit boy, Nuligak (later named Bob Cockney by the missionaries) came of age - fascinated by Herschel, but equally repelled by the excess of so-called civilization. Through Nuligak's touching yet tragic life-story expressed through his writings and echoed by his grandchildren's poignant return to the Island - we are offered a unique view into an often troubling past and a potentially hopeful future.

Description / Table of Contents: This book provides a sound introduction to the basic physical processes that dominate the workings of the Earth, its atmosphere and hydrosphere. It systematically introduces the physical processes involved in the Earth's systems without assuming an advanced physics or mathematical background.