Zobrazeno 1 - 10
of 66
pro vyhledávání: '"G. Keppel-Aleks"'
Autor:
Y. Guan, G. Keppel-Aleks, S. C. Doney, C. Petri, D. Pollard, D. Wunch, F. Hase, H. Ohyama, I. Morino, J. Notholt, K. Shiomi, K. Strong, R. Kivi, M. Buschmann, N. Deutscher, P. Wennberg, R. Sussmann, V. A. Velazco, Y. Té
Publikováno v:
Atmospheric Chemistry and Physics, Vol 23, Pp 5355-5372 (2023)
Atmospheric carbon dioxide (CO2) accounts for the largest radiative forcing among anthropogenic greenhouse gases. There is, therefore, a pressing need to understand the rate at which CO2 accumulates in the atmosphere, including the interannual variat
Externí odkaz:
https://doaj.org/article/c3960c34bc1645f38d44a446b27973fd
Autor:
L. Birch, C. R. Schwalm, S. Natali, D. Lombardozzi, G. Keppel-Aleks, J. Watts, X. Lin, D. Zona, W. Oechel, T. Sachs, T. A. Black, B. M. Rogers
Publikováno v:
Geoscientific Model Development, Vol 14, Pp 3361-3382 (2021)
The Arctic–boreal zone (ABZ) is experiencing amplified warming, actively changing biogeochemical cycling of vegetation and soils. The land-to-atmosphere fluxes of CO2 in the ABZ have the potential to increase in magnitude and feedback to the climat
Externí odkaz:
https://doaj.org/article/87c17dbc8b09490fac4d7058eb4da8f0
Publikováno v:
Biogeosciences, Vol 17, Pp 1293-1308 (2020)
Spatial and temporal variations in atmospheric carbon dioxide (CO2) reflect large-scale net carbon exchange between the atmosphere and terrestrial ecosystems. Soil heterotrophic respiration (HR) is one of the component fluxes that drive this net exch
Externí odkaz:
https://doaj.org/article/3eb16919a8d549898f4642a305bab22a
Publikováno v:
Biogeosciences, Vol 14, Iss 6, Pp 1383-1401 (2017)
The amplitude of the mean annual cycle of atmospheric CO2 is a diagnostic of seasonal surface–atmosphere carbon exchange. Atmospheric observations show that this quantity has increased over most of the Northern Hemisphere (NH) extratropics during t
Externí odkaz:
https://doaj.org/article/e9309218708f4cfa9efac5dd3350cae0
Autor:
D. Wunch, P. O. Wennberg, J. Messerschmidt, N. C. Parazoo, G. C. Toon, N. M. Deutscher, G. Keppel-Aleks, C. M. Roehl, J. T. Randerson, T. Warneke, J. Notholt
Publikováno v:
Atmospheric Chemistry and Physics, Vol 13, Iss 18, Pp 9447-9459 (2013)
We observe significant interannual variability in the strength of the seasonal cycle drawdown in northern midlatitudes from measurements of CO2 made by the Total Carbon Column Observing Network (TCCON) and the Greenhouse Gases Observing Satellite (GO
Externí odkaz:
https://doaj.org/article/ed51e2ff6eae40c6995caff76128c6b1
Publikováno v:
Atmospheric Chemistry and Physics, Vol 13, Iss 8, Pp 4349-4357 (2013)
We assess the large-scale, top-down constraints on regional fossil fuel emissions provided by observations of atmospheric total column CO2, XCO2. Using an atmospheric general circulation model (GCM) with underlying fossil emissions, we determine the
Externí odkaz:
https://doaj.org/article/3ea716d5187d48d19131af4363e64bd3
Autor:
G. Keppel-Aleks, P. O. Wennberg, R. A. Washenfelder, D. Wunch, T. Schneider, G. C. Toon, R. J. Andres, J.-F. Blavier, B. Connor, K. J. Davis, A. R. Desai, J. Messerschmidt, J. Notholt, C. M. Roehl, V. Sherlock, B. B. Stephens, S. A. Vay, S. C. Wofsy
Publikováno v:
Biogeosciences, Vol 9, Iss 3, Pp 875-891 (2012)
New observations of the vertically integrated CO2 mixing ratio, ⟨CO2⟩, from ground-based remote sensing show that variations in CO2⟩ are primarily determined by large-scale flux patterns. They therefore provide fundamentally different informati
Externí odkaz:
https://doaj.org/article/ec2121052011445cbe6e188dcce59ba1
Autor:
R. J. Salawitch, J. Robinson, C. M. Roehl, M. Rettinger, J. Notholt, F. A. Oyafuso, I. Morino, C. E. Miller, J. Messerschmidt, J. Mendonca, R. Macatangay, R. Lindenmaier, E. Kyrö, G. Keppel-Aleks, P. Heikkinen, M. Gunson, D. W. T. Griffith, M. L. Fisher, A. Eldering, N. M. Deutscher, D. Crisp, N. Cressie, R. Castano, S. C. Biraud, P. Ahonen, C. O'Dell, L. Mandrake, C. Frankenberg, G. B. Osterman, B. Fisher, B. J. Connor, G. C. Toon, P. O. Wennberg, D. Wunch, V. Sherlock, K. Strong, R. Sussmann, T. Tanaka, D. R. Thompson, O. Uchino, T. Warneke, S. C. Wofsy
Publikováno v:
Atmospheric Chemistry and Physics, Vol 11, Iss 23, Pp 12317-12337 (2011)
We describe a method of evaluating systematic errors in measurements of total column dry-air mole fractions of CO2 (XCO2) from space, and we illustrate the method by applying it to the v2.8 Atmospheric CO2 Observations from Space retrievals of the Gr
Externí odkaz:
https://doaj.org/article/35addcdc7b234ca6b46ef016b730f878
Publikováno v:
Atmospheric Chemistry and Physics, Vol 11, Iss 8, Pp 3581-3593 (2011)
Observations of gradients in the total CO2 column, 〈CO2〉, are expected to provide improved constraints on surface fluxes of CO2. Here we use a general circulation model with a variety of prescribed carbon fluxes to investigate how variations in
Externí odkaz:
https://doaj.org/article/9182c18fc2ad4df9a3b6c505a75147a7
Autor:
D. Wunch, G. C. Toon, P. O. Wennberg, S. C. Wofsy, B. B. Stephens, M. L. Fischer, O. Uchino, J. B. Abshire, P. Bernath, S. C. Biraud, J.-F. L. Blavier, C. Boone, K. P. Bowman, E. V. Browell, T. Campos, B. J. Connor, B. C. Daube, N. M. Deutscher, M. Diao, J. W. Elkins, C. Gerbig, E. Gottlieb, D. W. T. Griffith, D. F. Hurst, R. Jiménez, G. Keppel-Aleks, E. A. Kort, R. Macatangay, T. Machida, H. Matsueda, F. Moore, I. Morino, S. Park, J. Robinson, C. M. Roehl, Y. Sawa, V. Sherlock, C. Sweeney, T. Tanaka, M. A. Zondlo
Publikováno v:
Atmospheric Measurement Techniques, Vol 3, Iss 5, Pp 1351-1362 (2010)
The Total Carbon Column Observing Network (TCCON) produces precise measurements of the column average dry-air mole fractions of CO2, CO, CH4, N2O and H2O at a variety of sites worldwide. These observations rely on spectroscopic parameters that are no
Externí odkaz:
https://doaj.org/article/3e8fef0cbfe94ddf8a704bd08467ac5a