By Sandip R. Oza*, R. K. Kamaljit Singh*
and Megha Maheshwari*
*Scientists, Oceanic Sciences Division, Atmospheric and Oceanic Sciences Group, Space Applications Centre, Ahmedabad, India.
Polar ice regime plays an important role in the Earth's climate system. It consists of ocean, ice sheet, sea ice, ice shelf, atmosphere and polynyas. Because of the complex feedback mechanism amongst these components, improved knowledge of the physical processes is required for a better understanding of the potential changes in ice mass balance. The changes observed in Polar sea ice extent in the recent past are alarming. The present paper is focused on the changes observed over the Arctic and the Antarctic ice surface, sea-ice as well as ice-shelf, using the data derived from space-borne observations. The recent changes in the sea-ice concentration and ice-shelf melting are discussed in detail. The inter-relationship of sea-ice, sea surface temperature (SST) and ocean productivity and their year-to-year variations have also been discussed. The paper summarises the studies carried out at Space Applications Centre (SAC), Indian Space Research Organisation) for the assessment of Arctic and Antarctic sea ice extents and surface melting over east-Antarctic ice-shelves, using the space borne data.
Introduction Global climate change remains a topic of concern over the last few decades. The Arctic and the Antarctic polar regions are important components of the Earth’s climate system through their influence on the global atmospheric and oceanic circulations. Most of the global climate models predict the increase in Earth’s surface temperature with much larger increase over the polar regions. This warming phenomenon is also supported by the thinning as well as shrinking of Arctic sea ice cover. The Polar...