Post by jurinko on Jun 2, 2010 13:57:37 GMT
I have laboriously extracted HadCRUT and MSU trends from the KNMI site per 60x30° grids and compared their linear trends for the 1979-2010 period. At the end, I made the color map of differences between the trends in individual grids.
The color scale is still rather coarse, so 0.01 and 0.09 °C/decade has the same color, but never mind.
Several interesting observations:
a) Arctic area above 60°N runs even a bit colder according to HadCRUT than by MSU (but MSU has better coverage)
b) Northern extratropics have some regions quite different, but in general has the same trend per HadCRUT as per MSU (this is valid for the whole 30-90N area)
c) where HadCRUT gains a lot is station-free tropics (especially Africa), central Asia and UHI-rich Europe
d) southern extratropics (mostly ocean) are quite similar, showing that UHI-free HadSST trend agrees with MSU quite good
e) unlike Arctic, Antarctic is a bit colder per MSU, which has much better coverage (that very cold Antarctic section per HadCRUT had very incomplete record)
Northern Siberia is quite in agreement, but Southern Siberia (because of which Phil Jones "went to town") is much warmer in HadCRUT. There were reports recently, that northern Siberian stations are gradually dying out in some global datasets
Keep in mind, that tropic 60x30°grid is much bigger than 60x30°grid in Arctic, so the map is somehow distorted in favor of polar regions.
Notice that per MSU, there is no visible difference in trends above oceans or above ground for given latitude. This is in contrast with claim, that GH warming overheats the surface much more than oceans. For others, it is just a demonstration of UHI bias in surface record
The biggest positive difference of HadCRUT happens in tropics, where both station coverage and their quality is poor. Also, according to the "greenhouse theory", tropics should not warm at all, since excessive heat will be consumed for evaporation and high atmospheric humidity will overwhelm any CO2 increase. But in other areas, HadCRUT is not that bad. Definitely it is much better than GISTEMP, where you can observe truly "man made" warming of 0.3°C, created during the last 12 years
www.woodfortrees.org/plot/gistemp/from:1998/plot/hadcrut3vgl/from:1998
The color scale is still rather coarse, so 0.01 and 0.09 °C/decade has the same color, but never mind.
Several interesting observations:
a) Arctic area above 60°N runs even a bit colder according to HadCRUT than by MSU (but MSU has better coverage)
b) Northern extratropics have some regions quite different, but in general has the same trend per HadCRUT as per MSU (this is valid for the whole 30-90N area)
c) where HadCRUT gains a lot is station-free tropics (especially Africa), central Asia and UHI-rich Europe
d) southern extratropics (mostly ocean) are quite similar, showing that UHI-free HadSST trend agrees with MSU quite good
e) unlike Arctic, Antarctic is a bit colder per MSU, which has much better coverage (that very cold Antarctic section per HadCRUT had very incomplete record)
Northern Siberia is quite in agreement, but Southern Siberia (because of which Phil Jones "went to town") is much warmer in HadCRUT. There were reports recently, that northern Siberian stations are gradually dying out in some global datasets
Keep in mind, that tropic 60x30°grid is much bigger than 60x30°grid in Arctic, so the map is somehow distorted in favor of polar regions.
Notice that per MSU, there is no visible difference in trends above oceans or above ground for given latitude. This is in contrast with claim, that GH warming overheats the surface much more than oceans. For others, it is just a demonstration of UHI bias in surface record
The biggest positive difference of HadCRUT happens in tropics, where both station coverage and their quality is poor. Also, according to the "greenhouse theory", tropics should not warm at all, since excessive heat will be consumed for evaporation and high atmospheric humidity will overwhelm any CO2 increase. But in other areas, HadCRUT is not that bad. Definitely it is much better than GISTEMP, where you can observe truly "man made" warming of 0.3°C, created during the last 12 years
www.woodfortrees.org/plot/gistemp/from:1998/plot/hadcrut3vgl/from:1998
