Thursday, November 3, 2016

NCEP/NCAR October down 0.056C - NH sea ice very low..

The Moyhu NCEP/NCAR index dropped a little from 0.475°C in September to 0.419°C in October, neatly reversing the surprising rise from August to Sept. The change mirrors a small drop in UAH V5.6. Last month indices went in various directions, so what this means for this month in other indices is unclear.

More spectacular is a big deviation in Arctic sea ice after mid-October, in both JAXA and NSIDC. Here is the recent part of the radial plot, where black is 2016, and colors are other recent years:
JAXA Arctic Sea Ice October 2016NSIDC

It is such a remarkable change that a fault might be suspected, but it is the same from both sources. The plot shows a period of about a month, centred on present. The number values are here. Arctic temperatures have been warm.


  1. The UM CCI CFSV2 preliminary global temperature anomaly estimates dropped from 0.390C in September to 0.382C in October and 0.385C to 0.376C for WxBell CFSV2 final monthly estimates. The low ice extent in the Arctic appears to be related to very high daily temperature anomalies occurring since early October. The Antarctic daily temperature anomalies were also high in early October and have spiked up again in late October going into early November and may be related to the low ice extent there as well. I have graphed the UM CCI daily Arctic and Antarctic temperature anomalies here, since UM CCI does not provide graphs (WxBELL doesn't graph them either):

  2. Antarctic sea ice may be the bigger story. The October extent anomaly was the lowest since the 1980s and considerably outside the envelope of variability over the past couple of decades. I used the concentration data at Climate Explorer and found the average SH concentration (a bit different from extent, but close in practice) for October 2016 was below 5 standard deviations from the mean of Octobers over the previous decade.

    Perhaps worth being cautious given the recent satellite change, but could this be an indicator of a flip in Southern Ocean variability?

    1. If the PDO has flipped, looks like it has, and the Southern Ocean has flipped... broad Pacific resistance might make it harder for ENSO to slosh on over to La Nina conditions... for several more years... could be anthropogenic global warming and a higher observations-based TCR are about to get unmasked.

  3. Lol, I was worried Nick's NCEP anomaly would creep beyond .700 with the latest update... it came close to .800... not since March territory.