Correlations of salinity, temperature and ocean colour variations from SMOS and MODIS satellite data in the Eastern Mediterranean for creating an inventory data base as to be compared to conservative radionuclides for remote recording under routine and case

Περίληψη

A program concept has been developed to utilize sea surface salinity (SSS), sea surface temperature (SST) and ocean color parameters for the comparison to the inventory of artificial radionuclides, which are conservative and part of the sea salinity. As a pilot study, timeseries of SMOS and MODIS satellite measurements of ocean parameters are retrieved in order to investigate potential correlations to activity concentrations of 137Cs in the Aegean Sea (Greece) in order to develop an innovative tool for the remote radioactivity detection either for routine observations and emergency recordings. The presented first results are a part of this effort. Timeseries of SMOS sea surface salinity and temperatures as well as MODIS ocean colour parameters (e.g. SST and chlorophyll-a) spanning December 2011 to May 2014 are retrieved and correlated. The challenge of the study is the establishment of potential relations between satellite measurements of the marine environment and field readiological measurements resulting to a remote control tool for the radiological impact assessment under routine and event-case conditions. Results have shown that salinity retrievals currently present a high degree of noise and uncertainty due to high island density and RFI contamination. On the other hand, SST and chlorophyll distributions show inversely correlated seasonal patterns and a North to South gradients. Additionally, SST issued from SMOS and MODIS are highly correlated despite significant differences in spatial resolution and acquisition time in the day. Ongoing investigations for other spectral indicators of salinity changes from satellite measurements will provide additional information into establishing relations between satellite environmental monitoring and conservative radionuclide activity monitoring of the marine environment.