Melting of Arctic ice impacts weather in India.

• Rising temperature is causing sea-ice to melt, impacting ocean current linked to extreme weather events

• The study was conducted by Germany-based Alfred Wegener Institute (AWI), Helmholtz Centre for Polar and Marine Research

Months ahead of a major global expedition to explore the Arctic, researchers found that rising temperatures in the region is causing the sea-ice to melt faster than expected, impacting a major ocean current linked to extreme weather events.

The study was conducted by Germany-based Alfred Wegener Institute (AWI), Helmholtz Centre for Polar and Marine Research, whose researchers would spearhead MOSAiC, one of the biggest Arctic Research Expeditions set for sail this year, with participation from more than 17 countries.

The Arctic Ocean is surrounded by some marginal seas which constantly produce new ice in winters. The ice floes are transported from the Siberian part of the Arctic Ocean, across the Central Arctic and into the 600 km wide Fram Strait--the only gateway to the Arctic Ocean from the Atlantic Ocean.

This journey is enabled by a wind-driven current called the Transpolar Drift, one of the two major currents in the Arctic Ocean. The journey takes over 2-3 years, during which the ice floats increase in thickness (9.8-13.1 feet).

According to the latest research published in Scientific Reports, only 20% of the sea-ice that forms in the shallow Russian marginal seas of the Arctic Ocean is actually reaching the Central Arctic, where it joins the Transpolar Drift. The remaining 80% of the young ice melts before it reaches Central Arctic and is not thick anymore.

Till the 1990s, half of the ice from Russia’s shelf seas used to make this trans-arctic journey, said the researchers who monitored the movement of the sea-ice with the aid of satellite data for over two decades.

“The melting of sea ice in the marginal seas is now so rapid and widespread that we are seeing a lasting reduction in the amount of new ice for the Transpolar Drift," said the first author, Dr Thomas Krumpen, a sea-ice physicist at AWI. “On average, the ice is 30% thinner than it was 15 years ago. What we’re witnessing is a major transport current faltering, which is bringing the world one major step closer to a sea-ice-free summer in the Arctic."

The faltering of Transpolar Drift could lead to weather implications across countries, including India, as it is a major factor in Arctic Oscillations, a dominant climate pattern that influences weather throughout the Northern Hemisphere.

According to Indian scientists, it could have a bearing on the south-west monsoon.

“If there is less ice in the Arctic, the polar vortex instead of concentrating in the Arctic, will wobble and come up to mid-latitude. If it comes up to mid-latitude, then it will affect weather in India. We could see a rise in intensity and frequency of western disturbances," said Dr Ravichandran M, Director, National Centre for Polar and Ocean Research, Goa.

German researchers highlight that the weakening of Transpolar Drift is also reducing the natural transport of nutrients, algae, sediments and minerals from the Arctic to the Fram Straits, causing lasting changes in the biogeochemical cycles and ecological processes of the central Arctic Ocean in future.

Instead of Siberian minerals, we are now finding more remains of dead algae and microorganisms in our sediment traps," says co-author Eva-Maria Nöthig.

The changes in the biodiversity in the Arctic have been one of the focus areas of Indian researchers as well, who are trying to understand how the ecosystem is changing over the years due to global warming. “Arctic is more important to us. Sea ice is declining much faster in Arctic than Antarctic or the South Pole," said Dr Ravichandran. (Source: Livemint)