In a study conducted by India’s National Center for Polar and Ocean Research, scientists have found that the decline in the extent of sea ice in the Arctic and the loss of sea ice may be causing extreme rainfall from August to September in India. The study suggests a link between the increasing frequency of extreme rain in central India and the extent of summer sea ice loss in the Arctic.
The trend was found to be stronger during the most recent warming period after the 1980s, the study said. Since satellite records began in 1979, Arctic sea ice extent has declined at an annual average rate of about 4.4% per decade, according to the study published in the journal ‘Nature’ on June 22, 2021.
Over the past 30 years, the Arctic has warmed twice as fast as the entire globe – this phenomenon is known as Arctic Amplification, according to the US National Snow and Ice Data Center.
Although it is still unclear whether this rapid decline in sea ice can affect extreme weather events in the tropics or the extreme rainfall during the monsoon in India, scientists at NCPOR have determined that it could cause an area of high pressure over northwestern Europe.
“As sea ice decreases in the Barents and Kara Seas, there is more convection and upwelling over the open ocean in summer. The air moves towards northwest Europe and intensifies into a deep anticyclonic atmospheric circulation, eventually reaching subtropical Asia,” Sourav Chatterjee said, Lead author from NCPOR.
“We first looked at over 100 years of observational records of summer monsoon precipitation and sea ice in the Arctic. During the two episodes of rapid sea ice decline in the Arctic Ocean from 1920-1940 and 1980 to the present, the frequency of extreme rainfall increased steadily. This motivated us to investigate the relationship between extreme rainfall and sea ice in the Arctic,” Sourav Chatterjee continues.
Heiner Kubny, PolarJournal
Link to the study: Chatterjee, S., Ravichandran, M., Murukesh, N. et al. A possible relation between Arctic sea ice and late season Indian Summer Monsoon Rainfall extremes. npj Clim Atmos Sci 4, 36 (2021). https://doi.org/10.1038/s41612-021-00191-w