Arctic Sea Ice – highest since 2012-13
As far as I can see from the SII data that I download from the NSIDC, it looks like the Arctic sea ice season 2019-20 has returned the highest maximum sea ice extent in seven years to confound many of the experts. Admittedly a lot of the sea ice that the Arctic gained this winter will be in the form of new ice but the maximum of 15.155 million square kilometres that occurred on the 4th of March was just 2.2% below the long-term average for that date. There are all sorts of theories as to why Arctic sea ice did so well this winter, mine is that the polar vortex stayed fairly tight and didn’t split, and there were also no major incursions of mild air from the south.
Here’s a graph of the Arctic Oscillation from the CPC at the NWS to back up what I said.