A short introduction into downscaling

Uppsala, 30 September 2005

Disputation Frederik Wetterhall

1

A short introduction into downscaling

Hans von StorchInstitute for Coastal Research

GKSS Research CenterGermany

Uppsala, 30 September 2005

Disputation Frederik Wetterhall

2

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.

Uppsala, 30 September 2005

Disputation Frederik Wetterhall

3

The expectation of anthropogenic climate change – little doubt left.

Different scenarios describing plausible, possible and different futures.

Uppsala, 30 September 2005

Disputation Frederik Wetterhall

4

Uppsala, 30 September 2005

Disputation Frederik Wetterhall

5

TAR-“Consensus” on precip change in 2100

Uppsala, 30 September 2005

Disputation Frederik Wetterhall

6

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.

Uppsala, 30 September 2005

Disputation Frederik Wetterhall

7

Dynamical / empirical downscaling

Uppsala, 30 September 2005

Disputation Frederik Wetterhall

8

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

Uppsala, 30 September 2005

Disputation Frederik Wetterhall

9

And now …

Frederik Wetterhall

on

• Statistical downscaling

• of precipitation in Sverige och China