Abstract
Abstract. Antarctic sea ice sheets play an important role in modulating the climate system. The present study investigates the dynamics of melt/freeze over Amery and Ross ice shelf located in Eastern and Southern part of continent using OSCAT, the microwave scatterometer data from OCEANSAT2. The study utilizes the sensitivity of backscatter coefficient values of scatterometer data to presence of liquid water in the snow caused due to melt conditions. The analysis carried out for four austral winters from 2010–2013 and five austral summer from 2009–2014 showed spatial and temporal variations in average backscatter coefficient over Amery and Ross shelf areas. A dynamic threshold based on the austral winter mean and standard deviation of HH polarization is considered for pixel by pixel analysis for the shelf area. There is significant spatio-temporal variability in melt extent, duration and melt index as observed in the analysis. Spatially, the melt over Amery shelf moves from South to North along coast and West towards inner shelf area. Maximum mean melt occurs on 9th January with January 1–15 fortnight accounting for 80 % of the melt. Extreme low melt conditions were observed during summer 2010–11 and 2011–12 indicating cold summer. Summer 2012–13 and 2013–14 were warm summer. Year 2014 experienced melt only in the month of January with entire shelf under melt conditions. Practically no melt was observed over Ross ice shelf.
Highlights
Antarctic sea ice sheets play an important role in influencing the climate system
This can be visualised from the temperature time series shown in Figure 4 for Carolyn and Elaine points over Ross shelf where temperature remained at freezing conditions
In 2010, melt occurred in February in around 40-50% of the shelf area
Summary
Antarctic sea ice sheets play an important role in influencing the climate system. An increase in the western continent melt activity has been observed in the recent past which resulted in breaking of ice shelf from the continent(www.antarcticglaciers.org). Amery ice shelf is the major embayed shelf in East Antarctica. It is fed by massive inland Lambert Glacier basin. As per study by Lampkin & Karmosky (2009), the majority of surface melt is typically confined to the warm areas along the coastal ice shelf margin. Ojha et al(2011) studied the inter annual variations in surface melting over Amery ice shelf using QuikSCAT data for a period 2000 – 2009. The present study attempted to investigate the spatio-temporal dynamics in the surface melting along with melt duration over two ice shelves; Amery and Ross over Antarctica
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
