NSIDC Back on Line 4% Ice Loss is NO PROBLEM
Posted by Jeff Condon on February 28, 2009
Near-real-time sea ice data updates are again available from Arctic Sea Ice News & Analysis. We have switched to the Special Sensor Microwave/Imager (SSM/I) sensor on the Defense Meteorological Satellite Program (DMSP) F13 satellite following the sensor drift problem described in our February 18 post.
The temporary error in the near-real-time data does not change the conclusion that Arctic sea ice extent has been declining for the past three decades. This conclusion is based on peer reviewed analysis of quality-controlled data products, not near-real-time data.
They have taken slightly too much heat IMHO but it’s hard to imagine millions of dollars per year and they didn’t pick up on the problem sooner. Still it’s good news that the satellite is back on line. There are some very reasonable people in the NSIDC who I found very helpful, however you can imagine there are quite a few over the top AGW’ers.
On February 18, we reported that the F15 sensor malfunction started out having a negligible impact on computed ice extent, which gradually increased as the sensor degraded further. At the end of January, the F15 sensor underestimated ice extent by 50,000 square kilometers (19,300 square miles) compared to F13. That is still within the margin of error for daily data. By mid-February, the difference had grown to 500,000 square kilometers (193,000 square miles), which is outside of expected error. However, that amount represents less than 4% of Arctic sea ice extent at this time of year.
The last sentence is one of the best quotes I’ve found on global warming from a serious site. — Why? you ask. Because the entire melting of the ‘last 3 decades’ indicates the total global sea ice loss is only …………….. 4%.
Absolutely hilarious, ROTFL.
NSIDC stopped displaying the problematic data, and recalculated sea ice extent using data from the DMSP F13 satellite, an older sensor in the same series of satellites. The recalculation changed the January monthly average ice extent by less than the margin of error for the sensor. As we reported in our February 3 post, growth of Arctic sea ice did indeed slow in January because of unusual atmospheric conditions. Using F13 data instead of F15, the September daily minimum that we reported on September 16, 2008, changed from 4.52 million square kilometers (1.74 million square miles) to 4.54 million square kilometers (1.75 million square miles), within the margin of error for daily data.
This paragraph really bothers me, how can the data from a missing half million square kilometers of ice not be changed? They may be right but Steig 09 could have been right too. I like the guys I dealt with at NSIDC but there’s a bunch of people there who ‘may be’ adverse to being even slightly wrong and I don’t trust this.
Still they could be perfectly correct so until someone shows otherwise, that’s what we’ve got.