Melting in the Kara Sea

Latitudinal profile of backscatter variability during winter (April) and melting (June) periods. In June, AltiKa sees the melting of the wetlands on the South and beginning of melting (water accumulation in valleys) in Yamal. Ob' estuary in June is still frozen, but ice transformation resulted to 10 dB drop of Sigma0 in June. In the Kara Sea, AltiKa shows well the fine spatial structure of ice cover (fast ice, polynyas, floes etc.) and allows the studying of its dynamics. (Credits Legos)
The area as seen by Modis (credits NASA MODIS project gallery)

The new altimeter, AltiKa, onboard Saral (CNES/ISRO) continues to bring its share of results and studies. The spatial resolution of AltiKa is better adapted to study land hydrology ; we had a look in July 2013 (Image of the Month, Jul. 2013: Ob bogs and wetlands) at the first measurements of this altimeter on the North of Siberia. Further North of the Ob river, the Kara Sea is also seen by AltiKa, and the finer resolution also enable to distinguish there the effects of ice melting and also the presence of polylinias (areas free of ice on a frozen sea). Clear differences are visible between winter (in this case, April, the satellite having been launched late February) and the onset of Summer (July), with the melting of land and sea ice.