Polar Sea Ice Monitoring using SCATSAT-1 Data
Sea ice cover is an important parameter that indicates the polar response to climate change. Information on Sea ice condition is immensely useful for maritime navigation and understanding as well as forecasting oceanic circulation and earth climate changes. Sea ice acts as a thin insulator between the atmosphere and the ocean in the Polar Regions. Satellite remote sensing helps to monitor Sea ice condition on a global scale.
Ku-band Scatterometer on-board SCATSAT-1 (launched on September 26, 2016) is ISRO’s second space borne scatterometer similar to OSCAT on-board Oceansat-2. The payload instrument is a vital tool globally used to study wind patterns above the ocean, air-sea interactions, ocean circulation and their overall effects on weather patterns. Climate quality data will also provide accurate knowledge regarding Himalayan ice formation and melting, cyclones formation near Indian coastal line, Greenland ice melting etc.,
A hybrid classification technique has been developed to classify SCATSAT-1 data (2.25 km) for discriminating Sea ice and open ocean water. It uses σ0 composites in both the horizontal and vertical polarisations (σ0H and σ0V) and defines a normalised pseudo-polarisation quantity known as the Active Polarisation Ratio (APR).
A time series SCATSAT-1 data clearly shows the increasing Sea ice in the Arctic and decreasing Sea ice in the Antarctic from November 2016 to January 2017. It is shown in the 5-days interval animation prepared from the FCC of SCATSAT-1 (2.25 km) data over the Arctic and the Antarctic.
SCATSAT-1 Data Showing Sea Ice Variations over the Arctic and the Antarctic
|Increasing Sea Ice||Decreasing Sea Ice|
Level 4 data available from SCATSAT-1 detected an early formation of a polynya (an area of open water surrounded by Sea ice) near India Bay, the Antarctic coast near Maitri (an Indian Antarctic Research Station) in the 1st week of November 2016. By the 1st week of December 2016 the polynya became large in size. The analysis of 36 years of Sea ice occurrence probability data generated shows that the formation of this polynya takes place during the end of November and beginning of December months.
The changes in the Arctic summer minimum Sea ice cover were observed using SCATSAT-1 data (Oct. 02, 2016) and OSCAT data (Oct. 02, 2011). It was observed that Sea ice cover during 2016 is lower than that observed in 2011, which was earlier lowest Sea ice record.