engleski

Improving regional AVHRR SST measurements using AATSR SST data

The sea surface temperature (SST) is an important parameter in many disciplines (e.g. oceanography, meteorology or climatology). Satellite SST measurements from different sensors are available but such data collected over the same area often exhibit considerable mutual differences. Advanced Along Track Scanning Radiometer (AATSR) onboard the European Space Agency (ESA) ENVISAT platform currently provides the most accurate and precise measurements for deriving SST, whereas Advanced Very High Resolution Radiometer (AVHRR), MODerate resolution Imaging Spectroradiometer (MODIS), and Spinning Enhanced Visible Infra-Red Imager (SEVIRI) sensors render spatially and temporally denser coverage of a given area. In this study five different SST L2 products/datasets (NOAA17/AVHRR, METOPA/AVHRR, Terra/MODIS SST, Terra/MODIS SST4 and MSG/SEVIRI) and two auxiliary L2 products (MODIS Water vapour, MODIS Aerosol) were combined with a view to obtain better satellite estimates of the Adriatic Sea surface temperature. To that end, the AATSR-derived SST was used to improve estimates based on local collection of NOAA 17 AVHRR High Resolution Picture Transmission (HRPT) data stream. More specifically, six years (2003 – 2008) of AATSR and AVHRR SST L2 data were analyzed together with auxiliary aerosol and water vapour data from MODIS sensor aboard Terra platform for generation of new algorithms, while extension to 2010 was performed only for validation purposes of global SST products. The matchup data were stored in a relational SQL database to ensure smoother manipulation of couple of million data pairs. The analysis has shown that the application of all global SST night-time products to Adriatic Sea produces seasonality in the SST residuals (global SST - AATSR SST). A new set of AVHRR monthly- variable coefficients has produced an improvement in overall statistical parameters (night-time scatter is decreased from 0.46 to 0.34 K and bias from -0.07 K to -0.03 K) while eliminating noted seasonality in the residuals.

Sea surface temperature; Adriatic Sea; AVHRR; AATSR; MODIS; SEVIRI; Satellite

nije evidentirano