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
  • 1
    facet.materialart.
    Unknown
    Photochemical Impact on Ozone Fluxes in Coastal Waters (2012)
    Hindawi
    Details
    Publication Date: 2012-06-21
    Description: Ozone fluxes, derived from gradient measurements in Northeast Atlantic coastal waters, were observed to depend on both tide height and solar radiation. Peak ozone fluxes of −0.26±0.04 μg m-2 s-1 occurred during low-tide conditions when exposed microalgae fields contributed to the flux footprint. Additionally, at mid-to-high tide, when water surfaces contribute predominantly to the flux footprint, fluxes of the order of −0.12±0.03 μg m-2 s-1 were observed. Considering only fluxes over water covered surfaces, and using an advanced ozone deposition model that accounts for surface-water chemistry enhancing the deposition sink, it is demonstrated that a photochemical enhancement reaction with dissolved organic carbon (DOC) is required to explain the enhanced ozone deposition during daylight hours. This sink amounts to an ozone loss rate of up to 0.6 ppb per hour under peak solar irradiance and points to a missing sink in the marine boundary layer ozone budget.
    Print ISSN: 1687-9309
    Electronic ISSN: 1687-9317
    Topics: Geosciences , Physics
    Published by Hindawi
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 2
    facet.materialart.
    Unknown
    HOx budgets during HOxComp: A case study of HOx chemistry under NOx-limited conditions (2012)
    Wiley
    Details
    Publication Date: 2012-02-10
    Description: Recent studies have shown that measured OH under NOx-limited, high-isoprene conditions are many times higher than modeled OH. In this study, a detailed analysis of the HOx radical budgets under low-NOx, rural conditions was performed employing a box model based on the Master Chemical Mechanism (MCMv3.2). The model results were compared with HOx radical measurements performed during the international HOxComp campaign carried out in Jülich, Germany, during summer 2005. Two different air masses influenced the measurement site denoted as high-NOx (NO, 1–3 ppbv) and low-NOx (NO, 〈 1 ppbv) periods. Both modeled OH and HO2 diurnal profiles lay within the measurement range of all HOx measurement techniques, with correlation slopes between measured and modeled OH and HO2 around unity. Recently discovered interference in HO2 measurements caused by RO2 cross sensitivity was found to cause a 30% increase in measured HO2 during daytime on average. After correction of the measured HO2 data, the model HO2 is still in good agreement with the observations at high NOx but overpredicts HO2 by a factor of 1.3 to 1.8 at low NOx. In addition, for two different set of measurements, a missing OH source of 3.6 ± 1.6 and 4.9 ± 2.2 ppb h−1 was estimated from the experimental OH budget during the low-NOx period using the corrected HO2 data. The measured diurnal profile of the HO2/OH ratio, calculated using the corrected HO2, is well reproduced by the MCM at high NOx but is significantly overestimated at low NOx. Thus, the cycling between OH and HO2 is better described by the model at high NOx than at low NOx. Therefore, similar comprehensive field measurements accompanied by model studies are urgently needed to investigate HOx recycling under low-NOx conditions.
    Print ISSN: 0148-0227
    Topics: 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
  • 3
    facet.materialart.
    Unknown
    Global air pollution crossroads over the Mediterranean (2002)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2002-10-26
    Description: The Mediterranean Intensive Oxidant Study, performed in the summer of 2001, uncovered air pollution layers from the surface to an altitude of 15 kilometers. In the boundary layer, air pollution standards are exceeded throughout the region, caused by West and East European pollution from the north. Aerosol particles also reduce solar radiation penetration to the surface, which can suppress precipitation. In the middle troposphere, Asian and to a lesser extent North American pollution is transported from the west. Additional Asian pollution from the east, transported from the monsoon in the upper troposphere, crosses the Mediterranean tropopause, which pollutes the lower stratosphere at middle latitudes.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lelieveld, J -- Berresheim, H -- Borrmann, S -- Crutzen, P J -- Dentener, F J -- Fischer, H -- Feichter, J -- Flatau, P J -- Heland, J -- Holzinger, R -- Korrmann, R -- Lawrence, M G -- Levin, Z -- Markowicz, K M -- Mihalopoulos, N -- Minikin, A -- Ramanathan, V -- De Reus, M -- Roelofs, G J -- Scheeren, H A -- Sciare, J -- Schlager, H -- Schultz, M -- Siegmund, P -- Steil, B -- Stephanou, E G -- Stier, P -- Traub, M -- Warneke, C -- Williams, J -- Ziereis, H -- New York, N.Y. -- Science. 2002 Oct 25;298(5594):794-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Max Planck Institute for Chemistry, Post Office Box 3060, 55020 Mainz, Germany. lelieveld@mpch-mainz.mpg.de〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12399583" target="_blank"〉PubMed〈/a〉
    Keywords: Aerosols ; *Air Pollutants ; *Air Pollution ; Asia ; Atmosphere ; *Carbon Monoxide ; Climate ; Europe ; Mediterranean Region ; North America ; Ozone ; Weather
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 4
    facet.materialart.
    Unknown
    Photochemical Impact on Ozone Fluxes in Coastal Waters (2013)
    Hindawi
    Details
    Publication Date: 2013-01-22
    Description: Ozone fluxes, derived from gradient measurements in Northeast Atlantic coastal waters, were observed to depend on both tide height and solar radiation. Peak ozone fluxes of −0.26±0.04 μg m−2 s−1 occurred during low-tide conditions when exposed microalgae fields contributed to the flux footprint. Additionally, at mid-to-high tide, when water surfaces contribute predominantly to the flux footprint, fluxes of the order of −0.12±0.03 μg m−2 s−1 were observed. Considering only fluxes over water covered surfaces, and using an advanced ozone deposition model that accounts for surface-water chemistry enhancing the deposition sink, it is demonstrated that a photochemical enhancement reaction with dissolved organic carbon (DOC) is required to explain the enhanced ozone deposition during daylight hours. This sink amounts to an ozone loss rate of up to 0.6 ppb per hour under peak solar irradiance and points to a missing sink in the marine boundary layer ozone budget.
    Print ISSN: 1687-9309
    Electronic ISSN: 1687-9317
    Topics: Geosciences , Physics
    Published by Hindawi
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 5
    facet.materialart.
    Unknown
    Seasonal measurements of OH, NOx, and J(O1D) at mace head, Ireland (2013)
    Wiley
    Details
    Publication Date: 2013-03-15
    Description: [1]  Measurements of atmospheric OH concentrations were conducted between August 2010 and July 2011 at Mace Head showing maximum daytime values of 0.21 (±0.25) x 10 6  cm -3 in winter and 2.26 (±1.37) x 10 6  cm -3 in summer. Plots of OH vs. ozone photolysis frequency, J (O 1 D), exhibited strong linear correlations with slopes of 1.06 (± 0.05) x 10 11  cm -3  s (R = 0.75) in clean marine air and 1.31 (± 0.04) x 10 11  cm -3  s (R = 0.79) in mixed marine/continental air. Surprisingly, no significant difference in the former correlation was found between low and high tide periods. NO and NO 2 levels in air from the marine sector (190-300°) were typically below the detection limit (30 pptv) and 〈200 pptv, respectively. In the land sector, NO mixing ratios 〈50 pptv dominated most of the time suggesting that the atmospheric oxidation efficiency in this region is predominantly characterized by primary OH sources in a low NOx environment.
    Print ISSN: 0094-8276
    Electronic ISSN: 1944-8007
    Topics: 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
    Electronic Resource
    Electronic Resource
    Method for real-time detection of dimethyl sulfone in ambient air (1993)
    s.l. : American Chemical Society
    Analytical chemistry 65 (1993), S. 3168-3170 
    Details
    ISSN: 1520-6882
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ac00069a037
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    High-pressure chemical ionization flow reactor for real-time mass spectrometric detection of sulfur gases and unsaturated hydrocarbons in air (1992)
    s.l. : American Chemical Society
    Analytical chemistry 64 (1992), S. 283-288 
    Details
    ISSN: 1520-6882
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ac00027a008
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Real-time measurement of dimethyl sulfoxide in ambient air (1993)
    s.l. : American Chemical Society
    Analytical chemistry 65 (1993), S. 84-86 
    Details
    ISSN: 1520-6882
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ac00049a016
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Vertical distribution of dimethylsulfide, sulfur dioxide, aerosol ions, and radon over the Northeast Pacific Ocean (1988)
    Springer
    Journal of atmospheric chemistry 6 (1988), S. 149-173 
    Details
    ISSN: 1573-0662
    Keywords: Marine atmosphere ; seawater ; dimethylsulfide ; sulfur dioxide ; methanesulfonate ; nonsea-salt sulfate ; marine aerosol ; radon ; vertical distributions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract Dimethylsulfide (DMS), sulfur dioxide (SO2), methanesulfonate (MSA), nonsea-salt sulfate (nss-SO4 2−), sodium (Na+), ammonium (NH4 +), and nitrate (NO3 −) were determined in samples collected by aircraft over the open ocean in postfrontal maritime air masses off the northwest coast of the United States (3–12 May 1985). Measurements of radon daughter concentrations and isentropic trajectory calculations suggested that these air masses had been over the Pacific for 4–8 days since leaving the Asian continent. The DMS and MSA profiles showed very similar structures, with typical concentrations of 0.3–1.2 and 0.25–0.31 nmol m−3 (STP) respectively in the mixed layer, decreasing to 0.01–0.12 and 0.03–0.13 nmol m−3 (STP) at 3.6 km. These low atmospheric DMS concentrations are consistent with low levels of DMS measured in the surface waters of the northeastern Pacific during the study period. The atmospheric SO2 concentrations always increased with altitude from 〈0.16–0.25 to 0.44–1.31 nmol m−3 (STP). The nonsea-salt sulfate (ns-SO4 2−) concentrations decreased with altitude in the boundary layer and increased again in the free troposphere. These data suggest that, at least under the conditions prevailing during our flights, the production of SO2 and nss-SO4 2− from DMS oxidation was significant only within the boundary layer and that transport from Asia dominated the sulfur cycle in the free troposphere. The existence of a ‘sea-salt inversion layer’ was reflected in the profiles of those aerosol components, e.g., Na+ and NO3 −, which were predominantly present as coarse particles. Our results show that long-range transport at mid-tropospheric levels plays an important role in determining the chemical composition of the atmosphere even in apparently ‘remote’ northern hemispheric regions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00048337
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Airborne measurements of dimethylsulfide, sulfur dioxide, and aerosol ions over the Southern Ocean South of Australia (1990)
    Springer
    Journal of atmospheric chemistry 10 (1990), S. 341-370 
    Details
    ISSN: 1573-0662
    Keywords: Marine atmosphere ; Southern Ocean ; dimethylsulfide ; sulfur dioxide ; methanesulfonate ; non-sea-salt sulfate ; marine aerosol ; vertical distributions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract Vertical distributions of dimethylsulfide (DMS), sulfur dioxide (SO2), aerosol methane-sulfonate (MSA), non-sea-salt sulfate (nss-SO4 2-), and other aerosol ions were measured in maritime air west of Tasmania (Australia) during December 1986. A few cloudwater and rainwater samples were also collected and analyzed for major anions and cations. DMS concentrations in the mixed layer (ML) were typically between 15–60 ppt (parts per trillion, 10−12; 24 ppt=1 nmol m−3 (20°C, 1013 hPa)) and decreased in the free troposphere (FT) to about 〈1–2.4 ppt at 3 km. One profile study showed elevated DMS concentrations at cloud level consistent with turbulent transport (‘cloud pumping’) of air below convective cloud cells. In another case, a diel variation of DMS was observed in the ML. Our data suggest that meteorological rather than photochemical processes were responsible for this behavior. Based on model calculations we estimate a DMS lifetime in the ML of 0.9 days and a DMS sea-to-air flux of 2–3 μmol m−2 d−1. These estimates pertain to early austral summer conditions and southern mid-ocean latitudes. Typical MSA concentrations were 11 ppt in the ML and 4.7–6.8 ppt in the FT. Sulfur-dioxide values were almost constant in the ML and the lower FT within a range of 4–22 ppt between individual flight days. A strong increase of the SO2 concentration in the middle FT (5.3 km) was observed. We estimate the residence time of SO2 in the ML to be about 1 day. Aqueous-phase oxidation in clouds is probably the major removal process for SO2. The corresponding removal rate is estimated to be a factor of 3 larger than the rate of homogeneous oxidation of SO2 by OH. Model calculations suggest that roughly two-thirds of DMS in the ML are converted to SO2 and one-third to MSA. On the other hand, MSA/nss-SO4 2- mole ratios were significantly higher compared to values previously reported for other ocean areas suggesting a relatively higher production of MSA from DMS oxidation over the Southern Ocean. Nss-SO4 2- profiles were mostly parallel to those of MSA, except when air was advected partially from continental areas (Africa, Australia). In contrast to SO2, nss-SO4 2- values decreased significantly in the middle FT. NH4 +/nss-SO4 2- mole ratios indicate that most non-sea-salt sulfate particles in the ML were neutralized by ammonium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00053868
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...