Scientists have done us proud

The National Centre for Polar and Ocean Research (NCPOR) predicts that there would be a 24 per cent increase in the expansion of Ameri Ice Shelf (AIS) boundaries by 2021 and another 24 per cent expansion by 2026 from its 2016 positions. The prediction made by NCPOR is based on a 16-year-long satellite-based observation that covered an area of 60,000 sq. km across the AIS. Scientists feel that this study would help understand the ongoing changes in the ocean and atmospheric forces better.

The floating sheets of ice called the ice shelves play a multi-faceted role in maintaining the stability of a glacier. Ice shelves connect a glacier to the landmass. Because ice shelves already float in the ocean, they do not contribute directly to sea level rise when they break up. However, ice shelf collapse could contribute to sea level rise indirectly. Ice streams and glaciers constantly push on ice shelves, but the shelves eventually come up against coastal features such as islands and peninsulas, building pressure that slows their movement into the ocean. If an ice shelf collapses, the backpressure disappears.

The glaciers that fed into the ice shelf speed up, flowing more quickly out to sea. Glaciers and ice sheets rest on land, so once they flow into the ocean, they contribute to sea level rise. Research suggests that glaciers behind ice shelves may accelerate by as much as five times following a rapid ice shelf retreat. The AIS is one of the largest glacier drainage basins in the world, located on the east coast of Antarctica. The AIS dynamics and mass balance help in understanding the changes in the global climate scenario.

NCPOR carried out this study based on the satellite data collected from 2001 to 2016. It becomes clear from the study that the AIS is losing its stability owing to the impact of a downstream giant glacial drainage system over the past 19 years, thereby advancing the ice shelf boundaries. If this continues, it is entirely possible that in the next six years (2021 to 2026), the positions of the ice shelf would closely coincide with the actual boundary conditions.

NCPOR observations also revealed a critical cooling of the sea surface temperature (SST), resulting in an advancement of the ice shelf by 88 per cent in the past 15 years. These changes would contribute in a major way to climate variability. What does all this mean to us? In the background of the global warming scenario, the study reveals that the advancement in the predicted ice shelf extent closely corresponds with the actual extent.

The study clearly demonstrated the application of satellite observations and statistical techniques methods for the determination and validation; the reconstruction of the past; and the prediction of the future dynamism of ocean heat fluctuation and Antarctic Amery ice shelf mass shifting-extent. These are some of the groundbreaking methods crucial for monitoring and quantification of climate change effects and its consequences.

The methods could be replicated elsewhere as they are necessary for the understanding of the response of global climate change, its monitoring for sustainable environmental management. Our scientists have done us proud again by contributing immensely to the understanding of the impact of climate change on the ice continents. Hats off to them.