325
Temperature changes at 30 hPa rC]
0.0
0.0
-1.0
1.0
-2.0
2.0
1860
1880
1900
1920
1940
1960
1980
2000
2020
Figure 19: The same as Fig. 17 but for the predicted temperature change at 30 hPa.
Reference temperature -58.1°C (1860-1890).
climate models it was found that even atmospheric models with climatological SSTs have considerable variability on decadal timescales. At high
latitudes the size of the variability is practically the same as the variability of a fully coupled model. A 100 year integration with an atmospheric
model very similar to the one used in this experiment gave a very similar
result, demonstrating that atmospheric processes on its own can generate
substantial variability on decadal and longer time scales. For this reason
is it difficult to relate a particular climate aspect, such as an extreme in
the middle and high latitude general circulation to the surface boundary
conditions or to any other specific factor.
This aspect can be illustrated by a result from the coupled model. Fig.
20 shows the temperature difference between the 30 year mean 1960- 1990
and the 30 year mean 1930-1960. While the global temperature in this
period increased by 0.27°C in the experiment the temperature decreased
over the whole area from Scandinavia to central Canada between 50-70° N.
Around Greenland the fall in temperature is as high as 1°C! It is interesting
that a decrease in temperature over this length of time actually took place
in this area in reality. This is of course just coincidental, but illustrate
nevertheless the realism of the present simulation.
Temperature changes at 30 hPa rC]
0.0
0.0
-1.0
1.0
-2.0
2.0
1860
1880
1900
1920
1940
1960
1980
2000
2020
Figure 19: The same as Fig. 17 but for the predicted temperature change at 30 hPa.
Reference temperature -58.1°C (1860-1890).
climate models it was found that even atmospheric models with climatological SSTs have considerable variability on decadal timescales. At high
latitudes the size of the variability is practically the same as the variability of a fully coupled model. A 100 year integration with an atmospheric
model very similar to the one used in this experiment gave a very similar
result, demonstrating that atmospheric processes on its own can generate
substantial variability on decadal and longer time scales. For this reason
is it difficult to relate a particular climate aspect, such as an extreme in
the middle and high latitude general circulation to the surface boundary
conditions or to any other specific factor.
This aspect can be illustrated by a result from the coupled model. Fig.
20 shows the temperature difference between the 30 year mean 1960- 1990
and the 30 year mean 1930-1960. While the global temperature in this
period increased by 0.27°C in the experiment the temperature decreased
over the whole area from Scandinavia to central Canada between 50-70° N.
Around Greenland the fall in temperature is as high as 1°C! It is interesting
that a decrease in temperature over this length of time actually took place
in this area in reality. This is of course just coincidental, but illustrate
nevertheless the realism of the present simulation.