Some of you may recall that shortly after the leaked “Crutape letters”, Hadley yanked some of their monthly temperature data. This morning, some new data appeared updated through October, 2009. I was curious to see whether the data set I use for blog purposes had changed much. So, I compared Nov. and Dec. versions of anomalies posted under HadCrut NH & SH monthly averages.
The differences are tiny with all changes affecting posted anomalies no more than 1 year old. The effect on trends is also very tiny. Below, I show the least squares trends computed since January 2001. The results based on updated values are shown in red; the results based on values posted in November are shown in blue.
Whatever the reason for Hadley yanking temperatures during The Climate Gate incident, it does not appear to have had any impact on their estimates of the historic temperature anomalies.
OT
Meanwhile… the planet completely ignores the hub-bub and continues to do… what it does:
November (month end averages) NSIDC (sea ice extent)
30 yrs ago
1980 Southern Hemisphere = 16.7 million sq km
1980 Northern Hemisphere = 11.7 million sq km
Total = 28.4 million sq km
Recorded Arctic min yr.
2007 Southern Hemisphere = 16.1 million sq km
2007 Northern Hemisphere = 10.1 million sq km
Total = 26.2 million sq km
Last yr.
2008 Southern Hemisphere = 16.6 million sq km
2008 Northern Hemisphere = 10.6 million sq km
Total = 27.2 million sq km
This yr.
2009 Southern Hemisphere = 16.3 million sq km
2009 Northern Hemisphere = 10.3 million sq km
Total = 26.6 million sq km
1979-2000 Northern Hemisphere Nov. mean = 11.3 million sq km
1979-2000 Southern Hemisphere Nov. mean = 16.2 million sq km
Total mean = 27.5 million sq km
GK
edit
GK, yeah, ice varies. Sometimes it goes up. Sometimes it goes down. Sometimes you have multi-year periods of more ice, sometimes you have multi-year periods of less ice. The data is only since 1979. It is sort of like driving East from Denver for 1000 miles and assuming the drop in altitude continues forever while at the same time noticing that CO2 is rising and coming to the conclusion that the rise in CO2 is responsible for the change in altitude.
Here is a prediction for you … next year’s NH sea ice minimum will be higher than this year’s was barring a repeat of the 2007 wind anomaly. Reasoning? In 2007 a lot of 5+ year-old ice was blown into the Atlantic where it melted. It takes 5+ years to rebuild the inventory of 5+ year-old ice. Barring a repeat of the wind anomaly, the old ice inventory will recover in roughly 5 years. It is the old ice that resists summer melt and is most responsible for what remains at the end of the ablation season.
2008 saw significant recovery from 2007. 2009 saw continued recovery. I believe the chances are better for further recovery than for the opposite. Seeing 2010 NH sea ice minimum at or around 2006 levels would not surprise me.
That sea ice anomaly happens periodically and itself probably isn’t related to global warming.
I’ll remind people of Andrew Watt’s post on this.
Hey, it is just my regular monthly ice report. Personally, I feel there is too much ice, but what do I know? The numbers however show lots of ice, below mean, but lots of ice. I try not to comment inside the report, but present only the reported values. Usually, I have to defend the report from the AGW convinced. They/many just can’t believe how much ice is around. Different impact than a graph. Sorry again,OT
“That sea ice anomaly happens periodically and itself probably isn’t related to global warming.
I’ll remind people of Andrew Watt’s post on this.”
The plural of anecdote is not data.
Some would call 30 years of sea ice data anecdotal.