A dynamical reconstruction of detailed atmospheric and related regional variability, 1958-2000.

Hans von Storch, Frauke Feser, Ralf Weisse, Arnt Pfizenmayer, Katja Woth, Insa Meinke,

Mariza Cabral, Charlotte Hagner, Hilmar MessalInstitute for Coastal Research, GKSS Research Center,

Geesthacht, Germany

Wroclaw, 27. June 2003

a) The basic atmospheric reconstruction; dynamical downscaling, spectral nudging, validation

b) Applications – storms, (waves), lead transport, run-off

c) Scenarios of plausible future change

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Concept of Dynamical DownscalingRCM Physiographic detail

3-d vector of state

Known large scale state

projection of full state on large-scale scale

Large-scale (spectral) nudging

Large scale

Medium scale

Large scale

Medium scale

Spectral nudging vs. standard formulation

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Similarity of zonal wind at 850 hPa between simulations and NCEP re-analyses

large scales

medium scales

Spectral nudging vs. standard formulation

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Spectral nudging vs. standard formulation

HIPOCAS meeting Madrid Atmospheric fields REMO 5.0 run GKSS Frauke Feser

Mean monthly

precipitation [mm/month]

for 1999.

NCEP REMO

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Spectral nudging vs. standard formulation

Extreme wind speeds

20-year return values of wind speed,

based on daily 1992-97 data (color codes)

plus from station data in NL (numbers in black)

Southern North Sea

DWD REMO

Fese

r, p

ers

. co

mm

.

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Skill in representing marine winds

Red: buoy, yellow: radar, blue: wave model run with REMO winds

wave direction

significant wave height

[days]

[days]

Gerd Gayer, pers. comm., 2001

Lars Bärring, pers. comm., 2003

Estimatedlead emissions(from Pacyna and Pacyna, 2000)

1955

19951955

1975

deposition

Calculated depositions

1995

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model estimate

Analysis REMO simulation difference

Hill

mar

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20

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Arnt Pfizenmayer, pers. comm., 2003

REMO simulation (forced with NCEP gobal re-analysis)

Precipitation in the Odra catchment

Hillmar Messal, pers. comm.

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“SRES” ScenariosSRES = IPCC Special Report on

Emissions Scenarios

A world of rapid economic growth and rapidintroduction of new and more efficient technology.

A very heterogeneous world with an emphasis onfamily values and local traditions.

A world of “dematerialization” and introduction of clean technologies.

A world with an emphasis on local solutions toeconomic and environmental sustainability.

“ business as usual ” scenario (1992).

A1

A2

B1

B2

IS92a

IPC

C, 2

001

Scenario for changing precipitation in summer at the end of the 21st century

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Change (%) in

mean summer precipitation total in 99% quantile 5-daily precipitation amounts (rare events)

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Win

d statistics, A

2-scenario

for 2070-2100

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Conclusions

• Multi-decade reconstruction of hourly weather on 50 km grid in all of Europe available, 1958-2002.

• Several aspects checked but far from complete validation. Wind over the sea ok. Broad features of precip, cloudiness ok as well, but other quantities unknown.

• Data (wind, precip, temp ….) may be used to reconstruct various other environmental conditions, such as ocean waves, storm surges, flooding, extreme events, long range transport of matter.

• Data freely available for other research groups.• Polish groups welcome to validate, and use, data in

particular with respect to Polish territory.

Reconstruction of past decades (and longer) regional and local environmental conditions relevant …

• For determination of extreme events (frequency (Poison?), intensity) in terms of weather and impact variables. Preparation of adequate adaptation measures. Minimizing weather related risks.

• Basis of reconstruction of historical climate (transfer functions; proxy data; historical data).

• A posteriori analysis of past political regulations (example: lead, but also: flood protection).

• Determination of range of „normal“ variations, in order to discriminate between natural climate variability and man-made climate change („detection and attribution“).