the following are excerpts from a report yesterday on Carbon Brief, using satelite data from the US National Snow & Ice Data Center.
CARBON BRIEF:
"Arctic sea ice has reached its maximum extent for the year, peaking at 15.01m square kilometres (km2) on 14 March, according to provisional data from the NSIDC.
"this year’s Arctic winter peak, despite favourable winds that encouraged sea ice formation, was 640,000km2 smaller than the 1981-2010 average maximum, making it the 14th lowest in the satellite record.
“Overall, the road remains downhill for Arctic sea ice, but it is quite bumpy along the way,” another scientist tells Carbon Brief. This relatively high winter peak is “notable and a good reminder that we have to communicate and account for this type of weather variability when we talk about Arctic climate change”, he says.
"He adds that although the maximum is high compared to recent years, the ice is still “much thinner” than it was a few decades ago. The “wide coverage of this thinner ice” means total Arctic sea ice volume for the month of February was the third lowest on record.
"Arctic sea ice extent changes throughout the year. It grows each winter before reaching its peak for the year in February or March and then melts throughout the spring and summer towards its annual minimum, typically around September.
"Using satellite data, scientists can track the growth and melt of sea ice, allowing them to determine the size of the ice sheet’s winter maximum and summer minimum extent. These are key metrics to monitor the “health” of the Arctic sea ice.
"Dr Zack Labe – a postdoctoral researcher working at NOAA Geophysical Fluid Dynamics Laboratory and the atmospheric and oceanic sciences programme at Princeton University – tells Carbon Brief that “While this winter was yet again consistent with the long-term trend toward a warmer Arctic with less ice, regional weather patterns can still contribute to ice expansion and slower net declines, especially if the winds align from a north-to-south direction.”
"Arctic sea ice reached its minimum extent for 2023 on 19 September.
"With an extent of 4.23m km2, this was the sixth-lowest minimum on record and 1.99m km2 below the average minimum recorded over 1981-2010.
"Labe tells Carbon Brief that, overall, the Arctic winter can be characterised by “unusual warmth in the northern Arctic, but greater total ice extent”. This “counterintuitive” dynamic was caused by atmospheric circulation patterns, which led to “warmer, moist air blowing toward the north pole, while northerly winds contribute to expanding ice in the Greenland Sea and Sea of Okhotsk”, he says.
"Temperatures are usually “well-below freezing” over the Arctic Ocean in February, but the NSIDC notes that in 2024, they were not as low as usual for the time of year. Over the central Arctic ocean, air temperatures at 2,500 feet above sea level were up to 10C warmer than average.
"Labe notes that although sea ice extent was high compared to recent years, the ice is still “much thinner” than it was a few decades ago: “Total Arctic sea-ice volume ended up as the third lowest on record for the month of February due to the wide coverage of this thinner ice.”"
