Arctic sea ice melt continued over the past two days with both NSIDC and Cryosphere Today showing continued lower area and extent values. The Japanese Space Agency sea ice monitor (JAXA), showed slightly higher extent values but didn’t buck the overall melt trend. Overall, sea ice area measures are about 370,000 square kilometers below maximum. So a melt trend is pretty well established as the 500,000 square kilometer threshold approaches.
Historic Cracking Event
A very large cracking event that is unprecedented for its size so early in the season seemed to pause this weekend. That said, cracks did continue to appear in somewhat unlikely places. Poster Espen over at the Arctic Ice Blog pointed out a series of cracks from a NASA shot of Lancaster Sound. Located in the Canadian Arctic Archipelago, Lancaster Sound is a part of the network of seaways that make up the Northwest Passage. Early breakage in this region may, but does not conclusively, point toward an early opening of the Northwest Passage for this year. Will have to keep an eye on events as new conditions emerge.
(Image source: NASA Earth Data)
For an excellent overview of this major ongoing cracking event, take a look at this article written by Neven and re-posted both in Skeptical Science and Climate Progress.
Negative AO, Warming Subside
The extraordinarily powerful high pressure system contributing to a strong negative Arctic Oscillation (AO) has diffused into a larger ridge stretching from northern Russia to Baffin Bay. Pressures within the ridge have been slowly falling. As a result, negative AO phase has weakened somewhat, falling to a value of negative 4.5.
The Arctic has also cooled a little from earlier high temperatures. That said, temperatures remain above average for this time of year.
(Image source: DMI)
All that said, the overall blocking pattern transporting heat into the Arctic over Greenland and Eastern Siberia appears to remain intact. Further, the polar jet stream is very wavy, with lots of warm air intrusions from the south and cold air influxes from the north. Looking at weather models covering the next 10 days, this waviness in the jet stream appears to intensify as spring continues to emerge. This pattern is likely to drive warm air repeatedly into the Arctic’s heart while forcing colder air out and onto the continents.
Notable Weather Events
A low pressure system forming just east of Kamchatka disrupted thin sea ice in the region. This energetic low swirled the ice to such an extent that its effect was visible on the Navy sea ice thickness composite below. This mixing led to some loss of sea ice in the region. According to ECMWF model forecasts, the low is expected to strengthen and move toward the Barents Sea over the next couple of days. So areas of Barents sea ice may also see disruption as the low deepens and churn through the region. Later, another low is set to emerge again over The Sea of Okhotsk.
Overall, melt appears to be eroding ice in Baffin Bay (likely due to warmer than average conditions), in the region of The Sea of Okhotsk (storminess appears to be playing a role here), and in the fast ice just east of Greenland and on the south side of Svalbard. Spreading areas of thinner ice continue to emerge or remain north of Barrow Alaska and Northern Canada. A large fissure between the Canadian Arctic Archipelago and the thick ice that usually anchors there this time time of year continues to stress and disrupt the multi-year ice.
Weather conditions, though slightly less favorable than a couple of days ago, would seem to still contribute melt on the back of an over-all slow warming, erosion of the ice edge, record thin ice values, and a slow increase in sunlight typical for this time of year.
I’ll leave you with this image from the Canadian Weather Office. As you can see, some of the leads from this past month’s cracking event appear to have snowed over a bit. A view that appears serene and calm, for now.