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Table 3 Spearman's correlation
of GCM-projected climate
change ranking with observed
climate change ranking
Scenario
q
Temperature
Cool B1
0.01
Hot A2
-0.03
Precipitation
Dry B1
-0.13
Wet A2
-0.19
Temperature change
Precipitation change
K
mm yr
6
5
100
4
Warm wet A2
3
50
Cool dry B1
2
Observations
0
1
Fig. 5 Changes to temperature (left) and precipitation (right) from 1961-1990 to 1991-2009 for
observations and to 2040-2069 for GCM projections across 14 major Arctic basins. Error bars indicate the
range of different GCM results for both scenarios for each basin. Top ends of error bars extend one standard
deviation of model means from the A2 scenario ensemble mean, and bottom ends extend one standard
deviation of model means from the B1 scenario ensemble mean
with the strongest observed climate deviations is not reconcilable with prioritizing basins
with greatest anticipated future climate change. In this analysis, the question is not whether
models are able to reproduce observations, but whether the most (least) severe observed
deviations occur in the same places as the projected future most (least) severe changes. To
bring observed deviations in line with projections, continued increases are generally
needed but, for precipitation, the direction of deviations must in several cases be reversed
(Fig.
5
). With ongoing climate change, continued increases in the same direction are
naturally expected, as observations and projections concern different time periods in this
analysis. Developing monitoring to capture such monotonous changes in magnitude is then
one possible strategy. However, the disagreement in relative severity across basins between
observations and GCM projections implies that alternative monitoring prioritization con-
siderations are also possible and rational, as discussed further in Sect.
6.3
.
4 Results for Arctic Hydro-Climatic Change
In Bring and Destouni (
2011
), we have compared precipitation and discharge deviations
from the 1961 to 1990 climate average for the 14 major Arctic basins (green and blue
basins in Fig.
1
). A key result from that analysis is that the discharge deviation relations to
the corresponding deviations in precipitation vary widely for the major basins in the PADB
(Table
4
).
The
majority
of
basins
exhibit
excess
flow
deviation
in
relation
to
the
