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MAISIE Confirms Arctic Sea Ice Remaining Stable In February

Paul Homewood, Not A Lot Of People Know That & xmetman

This year is virtually bang on the MAISIE mean, and well above 2006.

While we’re on the topic of DMI Arctic sea ice graphs, it is worthwhile recalling Ron Clutz’s post the other day on NSIDC’s MAISIE data.

You may recall that Ron showed how MAISIE, which is the new all singing and dancing sea ice product, was showing about 500K km2 more ice than the old version, still used as their official publication.

NSIDC say this about MAISIE:

MASIE-NH stands for the Multisensor Analyzed Sea Ice Extent – Northern Hemisphere. It is similar to the Sea Ice Index (SII) product in that it is easy to use and gives a graphical view of ice extent in various formats. However, it relies more on visible imagery than on passive microwave data, so the ice edge position will generally be more accurate than that of the Sea Ice Index. The input is the daily 4-km sea ice component of the National Ice Center (NIC) Interactive Multisensor Snow and Ice Mapping System (IMS) product which is available separately at the NIC IMS Products Web page and IMS Daily Northern Hemisphere Snow and Ice Analysis at 4 km and 24 km Resolution data set at NSDIC. MASIE sea ice products are developed from NIC data with support from the U.S. Navy and from NOAA. MASIE is hosted by NOAA@NSIDC.

Note the words the ice edge position will generally be more accurate than that of the Sea Ice Index.

If we compare MAISIE data for Day 48, ie 17th Feb, we find that this year is virtually bang on the mean, and well above 2006.


You would not have guessed this from the graph that NSIDC want you to see. Both are based on 15% concentration, yet the old version below only shows 14.131 million sq km, as against 14.877 million sq km for MAISIE.

MAISIE, of course, only goes back to 2006, whereas the sea ice index dates to 1979. It is, however, easy to see why NSIDC are keen to use the latter as a starting point!

In much of the Arctic, the 1970s and 80s were amongst the coldest decades of the whole 20thC.

Full post

see also: xmetman — MASIE & SII northern hemisphere sea ice intercomparison