| Summary: | International audience The Arctic Ocean is a region where the impact of global change is detected on an annual basis by a wide varietyof observations: buoys, research vessels and aircrafts. But the large area involved and the need of frequentsampling make polar orbiting satellites a prime source of observations for documenting the corresponding fastchanges, especially in summer. Sun reflected measurements in the shortwave infrared (SWIR) region of thespectrum are not very sensitive because of the elevated solar zenith angle. In these conditions, thermal infrared(TIR) measurements using spectra collected by high spectral resolution nadir sounders are a good complement todocument the high latitudes regions. In the present work the spectra acquired by the TANSO-FTS instrument onGOSAT and by the IASI instrument on the MetOp platforms have been used to test the retrieval capabilities ofthese Fourier transform spectrometers to retrieve the carbon dioxide column averaged mixing ratio XCO 2 aswell as the sea surface temperature (SST) used as an inversion diagnostic. Results for 3 observing periods insummer (July, August, September) and 6 years (2010 to 2015) have been obtained in the latitude range 68N to82N over open water (no pack ice). The retrieved products have been analyzed from a climatologic point of viewto assess inter-annual variability and trends of TIR derived XCO 2 and SST zonal averages (3 summer monthsand 7 bins of 2° in latitude). Results will be described and compared with other sources of information. This typeof study is important for preparing future satellite missions like IASI-NG (a follow-on of IASI) and GOSAT-2 (afollow-on of GOSAT). Some specific regional Arctic Ocean basins will be compared to the zonal climatologies.
|
|---|