| Records |
| Author |
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| Title |
Interaction of Katabatic Flow With Local Thermal Effects in a Coastal Region of Adelie Land, East Antarctica
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Type |
Journal Article |
| Year |
1993 |
Publication |
J. Geophys. Res. |
Abbreviated Journal |
J. Geophys. Res. |
| Volume |
98 |
Issue |
D6 |
Pages |
10429 -10440 |
| Keywords |
|
| Abstract |
Katabatic flows largely dominate the climate of the Adelie Land coastal region. A detailed climatological data analysis of Dumont d'Urville has been conducted. Results of this study support the idea that katabatic flow can be locally enhanced by the diurnal cycle of solar insolation and the temperature contrast between the continent and the ocean. The interaction between katabatic wind and local thermal effects is expressed in terms of scale analysis. Except for surface stress, all terms in the momentum equation for a katabatic flow in a coastal region of Antarctica can reach the same order of magnitude. The local circulation then is the result of a relatively tenuous force balance which can be disrupted even by a weak perturbation of any term. To estimate the effect of the temperature contrast between the ocean and the continent on the katabatic flow, two numerical experiments have been conducted. The simulations consider an ocean free of sea ice representative of the summer months, and another winter case with the ocean covered by thick sea ice. These simulations show that with the ocean free of sea ice, the katabatic flows extend only a limited distance over the open ocean during the day due to the local thermal effects. With the ocean covered by sea ice, the katabatic winds are not constrained and extend a considerable distance offshore.
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| Programme |
211 |
| Campaign |
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| Address |
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| Corporate Author |
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Thesis |
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Publisher  |
AGU |
Place of Publication |
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Editor |
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| Language |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0148-0227 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
40 |
| Permanent link to this record |
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| Author |
Risi Camille, Landais Amaelle, Bony Sandrine, Jouzel Jean, Masson-Delmotte Valrie, Vimeux Franoise, |
| Title |
Understanding the 17O excess glacial-interglacial variations in Vostok precipitation
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Type |
Journal Article |
| Year |
2010 |
Publication |
J. Geophys. Res. |
Abbreviated Journal |
J. Geophys. Res. |
| Volume |
115 |
Issue |
D10 |
Pages |
D10112 - |
| Keywords |
17 O excess, ice core isotopic composition, surface relative humidity, 4932 Paleoceanography: Ice cores, 0454 Biogeosciences: Isotopic composition and chemistry, 0365 Atmospheric Composition and Structure: Troposphere: composition and chemistry, 1655 Global Change: Water cycles, 3344 Atmospheric Processes: Paleoclimatology, |
| Abstract |
Combined measurements of δ18O, δ17O, and δD in ice cores, leading to d excess and 17O excess, are expected to provide new constraints on the water cycle and past climates. We explore different processes, both in the source regions and during the poleward transport, that could explain the 17O excess increase by 20 per meg observed from the Last Glacial Maximum (LGM) to Early Holocene (EH) at the Vostok station. Using a single-column model over tropical and subtropical oceans, we show that the relative humidity at the surface is the main factor controlling 17O excess in source regions. Then, using a Rayleigh-type model, we show that the 17O excess signal from the source region is preserved in the polar snowfall, contrary to d excess. Evaporative recharge over mid and high latitudes and δ18O seasonality in polar regions can also affect the Vostok 17O excess but cannot account for most of the 20 per meg deglacial increase from LGM to EH. On the other hand, a decrease of the relative humidity at the surface (rhs) by 8 to 22% would explain the observed change in 17O excess. Such a change would not necessarily be incompatible with a nearly unchanged boundary layer relative humidity, if the surface thermodynamic disequilibrium decreased by 4C. Such a change in rhs would affect source and polar temperatures reconstructions from δ18O and d excess measurements, strengthening the interest of 17O excess measurements to better constrain such changes.
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| Programme |
458 |
| Campaign |
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| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
AGU |
Place of Publication |
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Editor |
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| Language |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0148-0227 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
201 |
| Permanent link to this record |
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| Author |
Genthon Christophe, Town Michael S, Six Delphine, Favier Vincent, Argentini Stefania, Pellegrini Andrea, |
| Title |
Meteorological atmospheric boundary layer measurements and ECMWF analyses during summer at Dome C, Antarctica
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Type |
Journal Article |
| Year |
2010 |
Publication |
J. Geophys. Res. |
Abbreviated Journal |
J. Geophys. Res. |
| Volume |
115 |
Issue |
D5 |
Pages |
D05104 - |
| Keywords |
Antarctica, boundary layer, ECMWF, 3307 Atmospheric Processes: Boundary layer processes, 0798 Cryosphere: Modeling, 0394 Atmospheric Composition and Structure: Instruments and techniques, |
| Abstract |
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| Programme |
1013 |
| Campaign |
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| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
AGU |
Place of Publication |
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Editor |
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| Language |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0148-0227 |
ISBN |
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Medium |
|
| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
|
Serial |
480 |
| Permanent link to this record |
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| Author |
Gouttevin I, Menegoz M, Domin F, Krinner G, Koven C, Ciais P, Tarnocai C, Boike J, |
| Title |
How the insulating properties of snow affect soil carbon distribution in the continental pan-Arctic area
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Type |
Journal Article |
| Year |
2012 |
Publication |
J. Geophys. Res. |
Abbreviated Journal |
|
| Volume |
117 |
Issue |
G2 |
Pages |
G02020- |
| Keywords |
Arctic, land-surface model, permafrost, snow, snow insulation, soil carbon, 0414 Biogeosciences: Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912), 0475 Biogeosciences: Permafrost, cryosphere, and high-latitude processes (0702, 0716), 1622 Global Change: Earth system modeling (1225, 4316), |
| Abstract |
We demonstrate the effect of an ecosystem differentiated insulation by snow on the soil thermal regime and on the terrestrial soil carbon distribution in the pan-Arctic area. This is done by means of a sensitivity study performed with the land surface model ORCHIDEE, which furthermore provides a first quantification of this effect. Based on field campaigns reporting higher thermal conductivities and densities for the tundra snowpack than for taiga snow, two distributions of near-equilibrium soil carbon stocks are computed, one relying on uniform snow thermal properties and the other using ecosystem-differentiated snow thermal properties. Those modeled distributions strongly depend on soil temperature through decomposition processes. Considering higher insulation by snow in taiga areas induces warmer soil temperatures by up to 12 K in winter at 50 cm depth. This warmer soil signal persists over summer with a temperature difference of up to 4 K at 50 cm depth, especially in areas exhibiting a thick, enduring snow cover. These thermal changes have implications on the modeled soil carbon stocks, which are reduced by 8% in the pan-Arctic continental area when the vegetation-induced variations of snow thermal properties are accounted for. This is the result of diverse and spatially heterogeneous ecosystem processes: where higher soil temperatures lift nitrogen limitation on plant productivity, tree plant functional types thrive whereas light limitation and enhanced water stress are the new constrains on lower vegetation, resulting in a reduced net productivity at the pan-Arctic scale. Concomitantly, higher soil temperatures yield increased respiration rates (+22% over the study area) and result in reduced permafrost extent and deeper active layers which expose greater volumes of soil to microbial decomposition. The three effects combine to produce lower soil carbon stocks in the pan-Arctic terrestrial area. Our study highlights the role of snow in combination with vegetation in shaping the distribution of soil carbon and permafrost at high latitudes.
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| Programme |
1017 |
| Campaign |
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| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
AGU |
Place of Publication |
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Editor |
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| Language |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0148-0227 |
ISBN |
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Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
|
Approved |
yes |
| Call Number |
|
Serial |
776 |
| Permanent link to this record |
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| Author |
Jourdain Bruno, Preunkert Susanne, Cerri Omar, Castebrunet Hlne, Udisti Roberto, Legrand Michel, |
| Title |
Year-round record of size-segregated aerosol composition in central Antarctica (Concordia station): Implications for the degree of fractionation of sea-salt particles
|
Type |
Journal Article |
| Year |
2008 |
Publication |
J. Geophys. Res. |
Abbreviated Journal |
J. Geophys. Res. |
| Volume |
113 |
Issue |
D14 |
Pages |
D14308 - |
| Keywords |
Central Antarctica, size segregated aerosol, sea-salt fractionation, 0305 Atmospheric Composition and Structure: Aerosols and particles, 0345 Atmospheric Composition and Structure: Pollution: urban and regional, 4801 Oceanography: Biological and Chemical: Aerosols, 4906 Paleoceanography: Aerosols, 0368 Atmospheric Composition and Structure: Troposphere: constituent transport and chemistry, 9310 Geographic Location: Antarctica, 4207 Oceanography: General: Arctic and Antarctic oceanography, 3300 Atmospheric Processes, |
| Abstract |
The origin of sea-salt aerosol that reaches the high Antarctic plateau and is trapped in snow and ice cores remains still unclear. In particular, the respective role of emissions from the open ocean versus those from the sea-ice surface is not yet quantified. To progress on this question, the composition of bulk and size-segregated aerosol was studied in 2006 at the Concordia station (75S, 123E) located on the high Antarctic plateau. A depletion of sulfate relative to sodium with respect to the seawater composition is observed on sea-salt aerosol reaching Concordia from April to September. That suggests that in winter, when the sea-salt atmospheric load reaches a maximum, emissions from the sea-ice surface significantly contribute to the sea-salt budget of inland Antarctica.
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| Programme |
414;903;1181 |
| Campaign |
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| Address |
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| Corporate Author |
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Thesis |
Bachelor's thesis |
| Publisher |
AGU |
Place of Publication |
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Editor |
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| Language |
|
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0148-0227 |
ISBN |
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Medium |
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| Area |
|
Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
1693 |
| Permanent link to this record |
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| Author |
Nevison Cynthia D, Mahowald Natalie M, Doney Scott C, Lima Ivan D, van der Werf Guido R, Randerson James T, Baker David F, Kasibhatla Prasad, McKinley Galen A, |
| Title |
Contribution of ocean, fossil fuel, land biosphere, and biomass burning carbon fluxes to seasonal and interannual variability in atmospheric CO2
|
Type |
Journal Article |
| Year |
2008 |
Publication |
J. Geophys. Res. |
Abbreviated Journal |
J. Geophys. Res. |
| Volume |
113 |
Issue |
G1 |
Pages |
G01010 - |
| Keywords |
atmospheric CO 2, interannual variability, seasonal cycles, transport model, 0428 Biogeosciences: Carbon cycling, 0414 Biogeosciences: Biogeochemical cycles, processes, and modeling, 0315 Atmospheric Composition and Structure: Biosphere/atmosphere interactions, 0312 Atmospheric Composition and Structure: Air/sea constituent fluxes, 0368 Atmospheric Composition and Structure: Troposphere: constituent transport and chemistry, |
| Abstract |
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| Programme |
416 |
| Campaign |
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| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
AGU |
Place of Publication |
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Editor |
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| Language |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0148-0227 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
|
Serial |
1710 |
| Permanent link to this record |
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| Author |
Patra P K, Law R M, Peters W, Rdenbeck C, Takigawa M, Aulagnier C, Baker I, Bergmann D J, Bousquet P, Brandt J, Bruhwiler L, Cameron-Smith P J, Christensen J H, Delage F, Denning A S, Fan S, Geels C, Houweling S, Imasu R, Karstens U, Kawa S R, Kleist J, Krol M C, Lin S-J, Lokupitiya R, Maki T, Maksyutov S, Niwa Y, Onishi R, Parazoo N, Pieterse G, Rivier L, Satoh M, Serrar S, Taguchi S, Vautard R, Vermeulen A T, Zhu Z, |
| Title |
|
Type |
Journal Article |
| Year |
2008 |
Publication |
Global Biogeochem. Cycles |
Abbreviated Journal |
|
| Volume |
22 |
Issue |
4 |
Pages |
GB4013 - |
| Keywords |
atmospheric CO 2, transport model, synoptic variations, 0368 Atmospheric Composition and Structure: Troposphere: constituent transport and chemistry, 0414 Biogeosciences: Biogeochemical cycles, processes, and modeling, 3329 Atmospheric Processes: Mesoscale meteorology, 3307 Atmospheric Processes: Boundary layer processes, |
| Abstract |
The ability to reliably estimate CO2 fluxes from current in situ atmospheric CO2 measurements and future satellite CO2 measurements is dependent on transport model performance at synoptic and shorter timescales. The TransCom continuous experiment was designed to evaluate the performance of forward transport model simulations at hourly, daily, and synoptic timescales, and we focus on the latter two in this paper. Twenty-five transport models or model variants submitted hourly time series of nine predetermined tracers (seven for CO2) at 280 locations. We extracted synoptic-scale variability from daily averaged CO2 time series using a digital filter and analyzed the results by comparing them to atmospheric measurements at 35 locations. The correlations between modeled and observed synoptic CO2 variabilities were almost always largest with zero time lag and statistically significant for most models and most locations. Generally, the model results using diurnally varying land fluxes were closer to the observations compared to those obtained using monthly mean or daily average fluxes, and winter was often better simulated than summer. Model results at higher spatial resolution compared better with observations, mostly because these models were able to sample closer to the measurement site location. The amplitude and correlation of model-data variability is strongly model and season dependent. Overall similarity in modeled synoptic CO2 variability suggests that the first-order transport mechanisms are fairly well parameterized in the models, and no clear distinction was found between the meteorological analyses in capturing the synoptic-scale dynamics.
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| Programme |
416 |
| Campaign |
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| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
AGU |
Place of Publication |
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Editor |
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| Language |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0886-6236 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
1713 |
| Permanent link to this record |
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| Author |
Gurney Kevin R, Baker David, Rayner Peter, Denning Scott, |
| Title |
Interannual variations in continental-scale net carbon exchange and sensitivity to observing networks estimated from atmospheric CO2 inversions for the period 1980 to 2005
|
Type |
Journal Article |
| Year |
2008 |
Publication |
Global Biogeochem. Cycles |
Abbreviated Journal |
|
| Volume |
22 |
Issue |
3 |
Pages |
GB3025 - |
| Keywords |
Carbon cycle, atmospheric inversion, interannual variability, 0414 Biogeosciences: Biogeochemical cycles, processes, and modeling, 0428 Biogeosciences: Carbon cycling, 0315 Atmospheric Composition and Structure: Biosphere/atmosphere interactions, 1615 Global Change: Biogeochemical cycles, processes, and modeling, |
| Abstract |
Interannually varying net carbon exchange fluxes from the TransCom 3 Level 2 Atmospheric Inversion Intercomparison Experiment are presented for the 1980 to 2005 time period. The fluxes represent the model mean, net carbon exchange for 11 land and 11 ocean regions after subtraction of fossil fuel CO2 emissions. Both aggregated regional totals and the individual regional estimates are accompanied by a model uncertainty and model spread. We find that interannual variability is larger on the land than the ocean, with total land exchange correlated to the timing of both El Nio/Southern Oscillation (ENSO) as well as the eruption of Mt. Pinatubo. The post-Pinatubo negative flux anomaly is evident across much of the tropical and northern extratropical land regions. In the oceans, the tropics tend to exhibit the greatest level of interannual variability, while on land, the interannual variability is slightly greater in the tropics and northern extratropics. The interannual variation in carbon flux estimates aggregated by land and ocean across latitudinal bands remains consistent across eight different CO2 observing networks. The interannual variation in carbon flux estimates for individual flux regions remains mostly consistent across the individual observing networks. At all scales, there is considerable consistency in the interannual variations among the 13 participating model groups. Finally, consistent with other studies using different techniques, we find a considerable positive net carbon flux anomaly in the tropical land during the period of the large ENSO in 1997/1998 which is evident in the Tropical Asia, Temperate Asia, Northern African, and Southern Africa land regions. Negative anomalies are estimated for the East Pacific Ocean and South Pacific Ocean regions. Earlier ENSO events of the 1980s are most evident in southern land positive flux anomalies.
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| Programme |
416 |
| Campaign |
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| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
AGU |
Place of Publication |
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Editor |
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| Language |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0886-6236 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
1723 |
| Permanent link to this record |
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| Author |
Sciare J, Favez O, Sarda-Estve R, Oikonomou K, Cachier H, Kazan V, |
| Title |
Long-term observations of carbonaceous aerosols in the Austral Ocean atmosphere: Evidence of a biogenic marine organic source
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Type |
Journal Article |
| Year |
2009 |
Publication |
J. Geophys. Res. |
Abbreviated Journal |
J. Geophys. Res. |
| Volume |
114 |
Issue |
D15 |
Pages |
D15302 - |
| Keywords |
organic aerosols, black carbon, biogenic aerosols, Austral Ocean, chlorophyll a, 0305 Atmospheric Composition and Structure: Aerosols and particles, 0365 Atmospheric Composition and Structure: Troposphere: composition and chemistry, 3339 Atmospheric Processes: Ocean/atmosphere interactions, |
| Abstract |
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| Programme |
414;415;416 |
| Campaign |
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| Address |
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| Corporate Author |
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Thesis |
Bachelor's thesis |
| Publisher |
AGU |
Place of Publication |
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Editor |
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| Language |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0148-0227 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
1819 |
| Permanent link to this record |
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| Author |
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| Title |
AIRS-based versus flask-based estimation of carbon surface fluxes |
Type |
Journal Article |
| Year |
2009 |
Publication |
J. Geophys. Res. |
Abbreviated Journal |
J. Geophys. Res. |
| Volume |
114 |
Issue |
D20 |
Pages |
D20303 - |
| Keywords |
CO 2 surface fluxes, inverse method, AIRS satellite data, 0322 Atmospheric Composition and Structure: Constituent sources and sinks, 0428 Biogeosciences: Carbon cycling, 0480 Biogeosciences: Remote sensing, 0365 Atmospheric Composition and Structure: Troposphere: composition and chemistry, 3315 Atmospheric Processes: Data assimilation, |
| Abstract |
This paper demonstrates an inversion of surface CO2 fluxes using concentrations derived from assimilation of satellite radiances. Radiances come from the Atmospheric Infrared Sounder (AIRS) and are assimilated within the system of the European Centre for Medium-Range Weather Forecasts. We evaluate the quality of the inverted fluxes by comparing simulated concentrations with independent airborne measurements. As a benchmark we use an inversion based on surface flask measurements and another using only the global concentration trend. We show that the AIRS-based inversion is able to improve the match to the independent data compared to the prior estimate but that it usually performs worse than either the flask-based or trend-based inversion. |
| Programme |
416 |
| Campaign |
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| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
AGU |
Place of Publication |
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Editor |
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| Language |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0148-0227 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
1837 |
| Permanent link to this record |
