a short introduction into downscaling

Uppsala, 30 September 2005

Disputation Frederik Wetterhall

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A short introduction into downscaling

Hans von StorchInstitute for Coastal Research

GKSS Research CenterGermany



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Overview•The perspective of anthropogenic climate change:

- needs for studying the sensitivity of the global system, and - the needs for adaptation on the regional

and local scale.

• Tools to do so: Global quasi-realistic climate models.

• Limitation in spatial resolution.

• Need for Downscaling: empirical and dynamical.



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The expectation of anthropogenic climate change – little doubt left.

Different scenarios describing plausible, possible and different futures.



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TAR-“Consensus” on precip change in 2100



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Response: adaptation and mitigation

- Mitigation (reduction of emissions) as much a we can afford (economically, socially); long term effort; long term gains; international efforts

- Adaptation to present extreme events – short term effort, local effort; useful if future extreme events are getting worse.



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Dynamical / empirical downscaling



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Change in total number of storm peak events (in %) from 1961-1990 to 2071-2100 simulated by a RCM/A2

Dynamical Downscaling

Empirical Downscaling

2 Examples

Projected change of flowering date of Galantis Nivalis in Northern Germany (days)

control2CO2

Rockel&Woth

Maak&

von S

torc

h



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And now …

Frederik Wetterhall

on

• Statistical downscaling

• of precipitation in Sverige och China

a short introduction into downscaling

Documents

precip change

local effort useful

future extreme events

different scenarios

short introduction

local scale

global system

frederik wetterhall