Our title for today is a reference back to a 2015 article by Paul Homewood on his “Not A Lot Of People Know That” blog, in which he told a load of old porky pies about the National Snow and Ice Data Center’s graphs of Arctic sea ice extent. Only last week Mr. Homewood cooked up another pile of porky pies concerning the Danish Meteorolical Institute’s Arctic sea ice extent metric. Now he has turned his pie baking skills to the Multisensor Analyzed Sea Ice Extent (MASIE for short), which is “a prototype collaborative product of the National Ice Center and NSIDC”.

Mr. Homewood obviously hadn’t done a whole lot of homework on MASIE before firing up his porky pie production line, since he used the self same recipe posted on the so called “Science Matters” blog of Ron Clutz shortly before. In fact he just reprinted the first part of Ron’s article and added a handy link to Ron’s even bigger pile of porky pies beneath it. Hence both Paul and Ron’s web sites currently proudly proclaim that:

Something strange is happening in the reporting of sea ice extents in the Arctic. I am not suggesting that “Something is rotten in the state of Denmark.” That issue about a Danish graph seems to be subsiding, though there are unresolved questions. What if the 30% DMI graph is overestimating and the 15% DMI graph is underestimating?

The MASIE record from NIC shows an average year in progress, with new highs occurring well above the 2015 maximum:

While I am compelled to agree with Ron and Paul that “something strange is happening in the reporting of sea ice extents in the Arctic” we disagree about everything else! One reason for that is because only a few days ago I interviewed NASA scientist Walt Meier following a suggestion by Ron Clutz that I do precisely that. Please read the edited highlights of that interview, and note in addition that Walt assured me that he had not previously been contacted by either of Messrs. Clutz and Homewood. Having never previously contacted Mr. Meier, here’s what Ron Clutz would have his loyal readership believe this weekend:

NOAA Is Losing Arctic Ice

Why the Discrepancy between SII and MASIE?

The issue also concerns Walter Meier who is in charge of SII, and as a true scientist, he is looking to get the best measurements possible. He and several colleagues compared SII and MASIE and published their findings last October. The purpose of the analysis was stated thus:

Our comparison is not meant to be an extensive validation of either product, but to illustrate as guidance for future use how the two products behave in different regimes.

Here is what Dr. Meier’s peer reviewed paper from October last year concluded on the matter:

Operational modelers require timely data that are as accurate as possible to initialize forecast models. In particular, an accurate ice edge is important because of the influence of the interaction of sea ice and water with the overlying atmosphere on the model fluxes. Consistency of data is also desirable for operational models, but is a secondary concern because the models are regularly reinitialized for their synoptic forecasts. Operational observations like MASIE make the most sense for these applications. However, the quality and amount of information used to produce the operational analyses vary.

Climate modelers desire consistent long-term data to minimize model biases and better understand and potentially improve model physics. The passive microwave record is useful, but has limitations. Regions of thin ice are underestimated and if the ice cover is diffuse with low concentration, ice-covered regions may be detected as open water. Even thin ice modifies heat and moisture transfer and thus may affect atmospheric and oceanic coupling. Surface melt results in an underestimation of concentration. This should be considered when evaluating model concentrations with passive microwave data.

and here once again is what he told me a few short days ago:

Since the quantity and quality of [MASIE] data varies the time series will not be consistent over time.

For some strange reasom Mr. Clutz’s article mentions none of this. Needless to say I have attempted to bring this unfortunate oversight to the attention of Ron & Paul:

Even more unfortunately it seems that their joint acute snow blindness has got even worse over the last few days, since they still haven’t noticed my link to Walt Meier’s words waiting patiently in their WordPress.com “moderation queues”.

Whilst we wish them on their recovery from their painful ailment, here’s an alternative interpretation of the MASIE data:

Operational modellers for the use of! Here’s what the NSIDC’s Sea Ice Index currently reveals to climate scientists:

NSIDC Arctic sea ice extent is evidently still currently lowest *ever for the date.