After all those negative records that were reported not so long ago (how many were there? I've lost count), it is nice to be once again given the opportunity to make known a positive record: Global sea ice area as reported on the Cryosphere Today website has been above the zero baseline for two days now (data here).
Even though the CT SIA anomaly dips ever lower, the anomaly can still go positive around this time of the year. This event follows the previous one a lot earlier than the one before that, which was a record 444 days and the first full calendar year of negative anomaly.
As usual the Antarctic sea ice anomaly is so positive that it compensates for the semi-permanent negative anomaly in the Arctic:
Even though almost all of the ice down under is thin first year ice that almost completely melts out every year, the circumstances are not conducive to melting. The NSIDC explains the why in their latest monthly report:
Turning to Antarctica, we note that January 2013 saw an unusual northward (towards the equator) excursion of sea ice in the Weddell Sea. The ice edge was found approximately 200 to 300 kilometers (124 to 186 miles) beyond its typical location. Overall, sea ice extent in the Antarctic was nearly two standard deviations above the mean for most of the month.
The cause of this is very unusual sea ice pattern appears to be persistent high pressure in the region west of the Weddell Sea, across the Antarctic Peninsula to the Bellingshausen Sea. This pressure pattern means that winds are tending to blow to the north on the east side of the Peninsula, both moving the ice northward and bringing in cold air from southern latitudes to reduce surface melting of the ice as it moves north.
I wonder when we will get a really long stretch of CT Global SIA negative anomaly? If summer trends in the Arctic keep up, it will have an increasing effect on winter trends, and I'm not sure for how much longer Antarctic sea ice can keep up. We'll see. As I always say, global SIA is an interesting statistic, as all statistics are, but it tells even less of the story than either of the two-dimensional graphs for the two poles tell. We await close encounters with the third dimension.