Summary of the Final Report of Research Results1) Title of the proposed research
Atmospheric Composition and Chemistry-Climate interactions with GOSAT
2) Principal Investigator (PI) and Co-Investigators (Co-Is)
PI:
Dr. Pierre-François Coheur
Co-I:
Dr. Lieven Clarisse
Dr. Daniel Hurtmans
Dr. Cathy Clerbaux
3) PI’s affiliation
Université Libre de Bruxelles4) Summary of the Final Report of Research Results
Radiance comparisons with IASI:
A relatively good agreement was found in the cross-comparison between the IASI and theTANSO-FTS co-located absolute thermal infrared radiance spectra for ocean surfaces, within thegeographical region between 115°W-135° W longitude and 20°S and 5°S latitude. A better
agreement between nighttime measurements is seen. Removing the cloudy scenes from theTANSO-FTS dataset confirms this tendency (Figure 1): a good linear relation is found, but with aremaining 2 K high bias for TANSO-FTS as compared to IASI, for the day-time data and a 0.7 K
low bias for night-time.
Trace gas retrievals from TANSO-FTS:
TANSO-FTS spectra have shown sufficient quality to provide useful information on reactive tracegases. Using a simple radiance indexing method based on brightness temperature differences(Clarisse et al., 2009), TANSO-FTS is likely more sensitive than IASI to detect ammonia in theboundary layer: the brightness temperature difference calculated from TANSO-FTS is significantly
higher (up to 2.5 K) than the values calculated from IASI (mostly around 0.3 K). This suggests abetter detection capability of TANSO-FTS for ammonia, complementing the less sensitivity but
much higher sampling of IASI.

Figure 1: Brightness temperature comparison between co-located (within 2° in latitude
and longitude and 3 h maximum time difference) and cloud-frees IASI and TANSO-FTS
spectra above oceans. The orange squares are for daytime, the blue circles to nighttime.

Analyses of TANSO-FTS spectra for extreme events:
The analysis of TANSO-FTS spectra during severe events, corresponding to large fires and volcanic
plumes, showed its capability to detect reactive trace species. HCOOH was detected during theRussian wildfires, its spectral signature shows up in the residual in addition to that of NH3 (Figure 2),
and SO2 was detected in the plume of the Merapi volcanic eruption. Note that it is the firstobservation of SO2 and HCOOH by TANSO-FTS. Overall the concentrations retrieved for these
species are in agreement with those of IASI.
Figure2: Spectral fit (blueline) of a TANSO-FTS
spectrum(greyline),measured in a fire plume,in Central Russia. The
bottom panel shows thebest

spectralresiduals(grey) compared to theresiduals when NH3 (blue)and HCOOH (red) areexcluded.

Clarisse, L., C. Clerbaux, F. Dentener, D. Hurtmans, P.-F. Coheur, Global ammonia distribution
derived from infrared satellite observations, 2009, Nature Geoscience, 2, 479-483.

5) List of publications relating to the proposed research
Master thesis
Santos, Barbara: A first analysis of the atmospheric measurements from TANSO/GOSAT, Masterthesis in Physics, ULB, 2010.
Abstracts and conference presentations
Conference abstract and presentations
Payan, S., Bureau, J., Camy-Peyret, C., Clerbaux, C., Coheur, P.-F., Hurtmans, D., Hadji-Lazaro,
J., & Bauduin, S. (2012). On the joint use of IASI and GOSAT retrievals in the thermal infrared.
Presented at the AGU Fall Meeting 2012, San Francisco, USA.