Advance in Sea Ice Studies in India

Abstract

Sea ice cover plays a key role in regulating the Earth's climate by influencing the global atmospheric and oceanic circulation through various feedback mechanisms. The only viable source for the continuous monitoring of sea ice cover, its variability and characterization in the vast and remote polr region is the utilization of data acquired by orbiting satellites supported by Ship based observations. India has been contributing significantly in the development of techniques for extraction of sea ice from state-of-art Indian sensors and other international missions. Significant progress has been made towards understanding sea ice variability in the Antarctic region. Based on various studies in polar regions, it has been observed that during last few decades, Arctic is showing the consistent decline of summer sea ice cover, in contrast to Antarctica which is showing regional anomalies with positive and negative trends. Role of sea ice concentration in Indian monsoon has also been examined. Relation of El Nino Southern Oscillation (ENSO) and sea ice extents have been studied. A climatic dataset of Sea Ice Occurrence Probability (SIOP) generated for the Antarctic region was used to compare the climatic sea ice growth and melt patterns in the eastern and the western regions of the Antarctic.This paper reviews the recent contributions mainly by Indian scientists in the studies of sea ice with inclusion of a few international scientific contributions. IntroductionAntarctic and Southern Ocean science is vital to understand natural climate variability, the processes that govern global change and the role of humans in the Earth and climate system (Kennicut II et al., 2015). Sea ice is an integral part of polar ocean-climate system. Sea ice dynamics and thermodynamics play an important role in the polar climate, which in turn influences the global oceanic and atmospheric circulation. The extent of global sea ice cover over the polar regions varies between 16.6×10 6 and 27.5×10 6 km 2 at any given time, which corresponds to around 3-6% of the earth's total surface area (Comiso, 2010). For instance, while the Arctic Ocean shows a 2-2.5 times increase in its sea ice cover from summer to winter, the Antarctic shows a five-to sixfold increase (Zwally et al. 1983; Gloersen et al. 1993, Simmonds, 2015. Monitoring of fluctuations of the Antarctic sea ice indicate an increase of about 2.4 % per decade. (Nayak, 2008). More specifically, Satellite passive-microwave data for the period November 1978-December 2010 reveal an overall positive trend in the ice extents of 17 100+2300 km 2 /year (Parkinson and Cavalieri, 2012). Such changes are primarily driven by the seasonal variation in atmospheric and oceanic conditions. The only viable source for the continuous monitoring of sea ice over the vast and remote polar region is the utilization of satellite remote sensing data.In the past one decade India has contributed significantly to an increased understanding of the ice variability around Antarctica using space-borne data. Development...

Exploring the Antarctic

“…have become available after the satellite era. The availability of space-borne sensors over the Polar Regions has offered an opportunity to monitor and generate forecasts for these usually inaccessible regions in near real time (Bhandari et al, 2002;Cavalieri et al, 1984;Oza et al, 2017a). Now-adays, sea ice products retrieved from the satellite data include sea ice extent, area, concentration, thickness and the age of the sea ice.…”