#ArcticSea; #Atlantification, #EuropeanSpaceAgency
New York/Canadian-Media: With alarm bells ringing about the rapid demise of sea ice in the Arctic Ocean, satellite data have revealed how the intrusion of warmer Atlantic waters is reducing ice regrowth in the winter. In addition, with seasonal ice more unpredictable than ever, ESA’s SMOS and CryoSat satellites are being used to improve sea-ice forecasts, which are critical for shipping, fisheries and indigenous communities, for example.
CryoSat Satellite. Image credit: ESA
The amount of sea ice floating in the Arctic Ocean varies enormously as it grows and shrinks with the seasons. Although some of the older thicker ice remains throughout, there is an undeniable trend of declining ice as climate change tightens its grip on this fragile polar region.
Arctic sea ice reaches a maximum around March after the cold winter months and then shrinks to a minimum around September after the summer melt. However, these seasonal swings are not only linked to the changing seasons — it transpires that along with our warming climate, the temperature of adjacent ocean seawater is now also adding to the ice’s vulnerability.
Previous research suggested that sea ice can partly recover in the winter following a strong summer melt because thin ice grows faster than thick ice. However, new findings indicate that heat from the ocean is overpowering this stabilising effect — reducing the volume of sea ice that can regrow in the winter. This means that sea ice is more vulnerable during warmer summers and winter storms.
The research published recently in the Journal of Climate describes how scientists used satellite data from ESA’s Climate Change Initiative to calculate changes in the volume of Arctic sea ice between 2002 and 2019.
Robert Ricker, from the AWI Helmholtz Centre for Polar and Marine Research in Germany, and colleagues mapped regional changes in sea-ice volume owing to drift and calculated how much ice grows because of freezing each month. They also used model simulations to explore the causes of change, which corroborated their findings.
Dr Ricker said, “Over the last decades we observed the tendency that the less ice you have at the…