By Steven Goddard
As discussed in my last post, GISS claims to have better Arctic coverage than Had-Crut, and uses that as an explanation of why they are trending upwards when Had Crut isn’t.
“A likely explanation for discrepancy in identification of the warmest year is the fact that the HadCRUT analysis excludes much of the Arctic ….. (whereas GISS) estimates temperature anomalies throughout most of the Arctic.”
In this post, I will show a number of things wrong with that claim. GISS uses the maps below as evidence of their better coverage.
The problem is though, that GISS actually has very little Arctic data. The “GISS 2005” map above uses 1200 km smoothing (which assumes that the weather in London somehow affects the weather in Monaco.) If we look at the un-smoothed GISS data from 2005 (below) we see something very different.
GISS actually has very few temperature readings in the Arctic. much less than Had-Crut. The map below shows the differences in coverage. Areas where Had Crut has better coverage are shown in green. Areas where GISS has better coverage are shown in red. Note that Had-Crut has more extensive coverage than GISS on almost every continent.
Now, let’s look at some of the specific problems with the GISS smoothing in the blink map below, which alternates between Had-Crut and GISS 2005 data.
- GISS completely missed a cold area north of Svalbard. They show that region several degrees above normal.
- GISS has almost no coverage in the Canadian Arctic
- GISS has almost no coverage in Greenland
- GISS has no coverage in the Chukchi Sea or Arctic Basin
- GISS has very poor coverage around Antarctica
- GISS has very poor coverage in Africa
- GISS missed large regions of below normal temperatures in the southern oceans and Antarctica
Now, let’s compare GISS Arctic coverage with UAH, below. Note that UAH has much better coverage at both poles than GISS (as well as everywhere else.)
Conclusion: GISS implications that that they have better Arctic coverage than other sources are simply untrue. They have very little actual data near either pole, and their extrapolations in those regions are demonstrably poor.