The Synergy of Active and Passive Sensors for Arctic Sea Ice Monitoring
Abstract
The Arctic sea ice extent is one of the most striking indicator of global warming and climate change On the long run and at polar ocean scale climate modelers are forecasting a drastic reduction of the sea ice extent in summer At most some of these models even predict a complete ice free Arctic ocean by the end of the century In fact this indicator is a measure of the area of perennial Multi-year - MY- sea ice over the Arctic Ocean This indicator varies from year to year and is time dependant during its annual cycle The MY ice area is maximum at the end of the melting period early autumn when the remaining sea ice of the previous winter becomes by definition the MY ice for the new freezing period All year long a significant portion of this MY ice is exported from the Arctic Ocean to the Atlantic Ocean mainly via the Fram Strait or melts during summer On the short run and at local scale multi-year sea ice is a proxy for sea ice thickness This late parameter impacts both the heat budget balance and the fresh water flux to the ocean for ocean circulation models It is thus important to be able to discriminate and monitor as often as possible MY from First Year FY ice and also to follow the sea ice drift Since the late 1970 s the brightness temperatures of microwave radiometer flown onboard polar orbiting satellites are used to produce daily sea ice extent and total sea ice concentration maps These estimations are quite robust because in this range of frequencies the emissivity of sea ice is about twice that of sea water which
- Publication:
-
36th COSPAR Scientific Assembly
- Pub Date:
- 2006
- Bibcode:
- 2006cosp...36....9E