Delayed Mode Monitoring of Greenhouse Gases
|Delayed mode monthly mean fields|
| ||Monthly mean pressure level fields for CH4 and CO2 from the delayed-mode production stream. The delayed-mode stream is running about 5 months behind real-time to make maximum use of satellite and in-situ observations that are currently not provided in real-time. The output of the delayed-mode monitoring is used in the delayed-mode flux inversions.|
|Delayed mode monthly mean total columns|
| ||Monthly mean total column fields for CH4 and CO2 from the delayed-mode production stream. The delayed-mode stream is running about 5 months behind real-time to make maximum use of satellite and in-situ observations that are currently not provided in real-time. The output of the delayed-mode monitoring is used in the delayed-mode flux inversions.|
|Delayed mode methane flux inversions|
These monthly mean plots illustrate the flux inversion from the MACC delayed-mode analysis
of CH4 concentrations, based on the TM5-4DVAR inverse modeling system [Bergamaschi et al., 2009]. While the MACC delayed-mode
analysis assimilates SCIAMACHY CH4 retrievals into the IFS model, we use in addition also high accuracy surface measurements
from the NOAA global cooperative air sampling network in the inversion. The latter constrain significantly the surface mixing ratios in
remote regions (ocean) and allow deriving corrections for potential small latitudinal or seasonal biases of the satellite
data. 3D fields of CH4 mixing ratios from the TM5-4DVAR inversion are available upon request.
While the results shown here present our first best effort, using NRT delayed-mode observations with some preliminary
quality control, the inversion set-up is still being improved and therefore results should not be taken as final.
We thank Ed Dlugokencky for provision of surface measurements from the NOAA Earth System Research Laboratory (ESRL)
global cooperative air sampling network.
Bergamaschi, P., C. Frankenberg, J. F. Meirink, M. Krol, M. G. Villani, S. Houweling, F. Dentener, E. J. Dlugokencky, J. B.
Miller, L. V. Gatti, A. Engel, and I. Levin, Inverse modeling of global and regional CH4 emissions using SCIAMACHY satellite
retrievals, J. Geophys. Res., 114, doi:10.1029/2009JD012287, 2009.
|Delayed mode carbon dioxide flux inversions|
This data describes the CO2 surface fluxes over more than three decades, from 1979 to 2011, at resolution 3.75° x 2.5° (longitude-latitude) and 3-hourly, based on 136 CO2 mole fraction station records from four large databases:
- the NOAA Earth System Research Laboratory archive (NOAA CCGG),
- the CarboEurope atmospheric archive (CarboEurope),
- the World Data Centre for Greenhouse Gases archive (WDCGG),
- the Réseau Atmosphérique de Mesure des Composés à Effet de Serre database (RAMCES).
The four databases include both in situ measurements made by automated quasi-continuous analysers and irregular air samples collected in flasks and later analyzed in central facilities.
The flux inversion builds on a variational Bayesian inversion system, like the 4D-Var data assimilation system used in MACC-II, which allows the fluxes to be estimated at relatively high resolution over the globe. It uses a single 33-year inversion window, therefore enforcing the physical and statistical consistency of the inverted fluxes. Fluxes and mole fractions are linked in the system by a global atmospheric transport model. A series of flux inventories, flux climatologies and flux error models regularizes the solution to the flux inference problem. The uncertainty of the inverted fluxes is quantified from the Bayesian theory by a robust Monte Carlo method.
The inversion results can be downloaded in the form of NetCDF files from: http://www-lscedods.cea.fr/invsat/PYVAR11_MACC/V2/
Chevallier, F., M. Fisher, P. Peylin, S. Serrar, P. Bousquet, F.-M. Bréon, A. Chédin, et P. Ciais (2005), Inferring CO2 sources and sinks from satellite observations: method and application to TOVS data. J. Geophys. Res., 110, D24309, doi:10.1029/2005JD006390.
Chevallier, F., F.-M. Bréon, and P. J. Rayner (2007), The contribution of the Orbiting Carbon Observatory to the estimation of CO2 sources and sinks: theoretical study in a variational data assimilation framework. J. Geophys. Res., 112, D09307, doi:10.1029/2006JD007375.
Chevallier, F., et al. (2010), CO2 surface fluxes at grid point scale estimated from a global 21-year reanalysis of atmospheric measurements. J. Geophys. Res., 115, D21307, doi:10.1029/2010JD013887
|Delayed mode nitrous oxide flux inversions|
This data describes the N2O surface fluxes over 12 years, from 1998 to 2009, at 3.75° x 2.5° (longitude-latitude) and monthly resolution, based on air mole fraction records from 70 N2O sites plus ship-based and ocean mooring records from:
These databases include both in situ measurements made by automated quasi-continuous analysers and irregular air samples collected in flasks and later analyzed in central facilities.
The flux inversion is based on a variational Bayesian inversion system, like the 4D-Var data assimilation system used in MACC-II, which allows the fluxes to be estimated at relatively high resolution over the globe. Fluxes and mole fractions are linked in the system by a global atmospheric transport model, which accounts for the loss of N2O in the stratosphere via photolysis and reactions with metastable oxygen atoms O( 1D ). A series of flux model simulations, flux inventories, and flux error models regularizes the solution to the flux inference problem. The uncertainty of the inverted fluxes is quantified from the Bayesian theory by a robust Monte Carlo method.
The inversion results can be downloaded in the form of NetCDF files from: http://www-lscedods.cea.fr/invsat/PYVAR11_MACC/N2O/
Thompson, R., P. Bousquet, F. Chevallier, P. Rayner, P. Ciais, 2011: Impact of the atmospheric sink and vertical mixing on nitrous oxide fluxes estimated using inversion methods. J. Geophys. Res., 116, D17307 (http://onlinelibrary.wiley.com/doi/10.1029/2011JD015815/abstract)
These monthly mean maps (2x2 degrees) show the column-averaged methane mixing ratios retrieved from SCIAMACHY onboard ENVISAT using the IMAP algorithm version 6.0 [Frankenberg et al. 2005, 2008a, 2008b, 2011]. The IMAP algorithm uses the proxy method to account for lightpath modifications. To this end, CH4 is retrieved simultaneously with carbon dioxide (CO2) and their ratio is multiplied with modelled CO2 fields from CarbonTracker [Peters et al. 2007].
Frankenberg, C., J. F. Meirink, M. van Weele, U. Platt, and T. Wagner (2005), Assessing Methane Emissions from Global Space-Borne Observations, Science, 308 (5724), 1010-1014, doi:10.1126/science.1106644.
Frankenberg, C., P. Bergamaschi, A. Butz, S. Houweling, J. Meirink, J. Notholt, A. Petersen, H. Schrijver, T. Warneke, and I. Aben (2008a), Tropical methane emissions: A revised view from SCIAMACHY onboard ENVISAT, Geophys. Res. Lett., 35 (5), L15811, doi:10.1029/2008GL034300.
Frankenberg, C., T. Warneke, A. Butz, I. Aben, F. Hase, P. Spietz, and L. R. Brown (2008b), Pressure broadening in the 2v3 band of methane and its implication on atmospheric retrievals, Atmospheric Chemistry and Physics, 8 (17), 5061-5075, doi:10.5194/acp-8-5061-2008.
Frankenberg, C., I. Aben, P. Bergamaschi, E. J. Dlugokencky, R. van Hees, S. Houweling, P. van der Meer, R. Snel, and P. Tol (2011), Global column-averaged methane mixing ratios from 2003 to 2009 as derived from SCIAMACHY: Trends and variability, J. Geophys. Res., 116, D04302, doi:10.1029/2010JD014849.
Peters, W. et al. (2007), An atmospheric perspective on North American carbon dioxide exchange: CarbonTracker, PNAS, 104 (48),18925-18930, doi:10.1073/pnas.0708986104.