Service Group Adaption – SGA Project hosted at Model
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Transcript Service Group Adaption – SGA Project hosted at Model
Service Group Adaption – SGA
Project hosted at Model & Data / MPI-M, Hamburg, Germany
Change of Wind Speed in Europe in
Regional Climate Model Scenario
Projections
B. Hennemuth, H.-D. Hollweg, M. Schubert
(SGA / M&D / MPI-M)
DEWEK 2008, Bremen 26.11.2008
Content
Introduction SGA, climate change
Regional model, data base
Methodology
Climatological averages
Statistics of wind speed and wind
speed change
Summary and outlook
(SGA / M&D / MPI-M)
DEWEK 2008, Bremen 26.11.2008
Introduction
Introduction SGA
Service Group Adaptation has been established by
German Federal Ministry of Education and Research
(BMBF) to assist projects which develop strategies for
adaptation to climate trends and extreme weather.
SGA provides a common data base of regional climate
model data.
SGA gives assistance with methods
to analyse climate data.
SGA is hosted at the Max-Planck-Insitute for Meteorology
in Hamburg, Germany, as project at the national data
service group ‘Model and Data‘.
(SGA / M&D / MPI-M)
DEWEK 2008, Bremen 26.11.2008
Introduction
Global climate models
• Simulate all relevant processes
in ocean, atmosphere, and (biosphere)
on a global grid by physical equations.
• Small-scale processes
(clouds, precipitation, radiation, soil,
turbulence, etc. ) are
described by large-scale parameters.
(SGA / M&D / MPI-M)
DEWEK 2008, Bremen 26.11.2008
Introduction
Global climate models
• start with a pre-industrial long-term
simulation with constant concentration of
greenhouse gases.
• calculate present-day climate with realistic
greenhouse gas concentration
from 1860 to 2000.
• scenario projections of economic growth to
assess corresponding future climates.
• do this for different starting points
from pre-industrial equilibrium run
different realizations Ensemble
(SGA / M&D / MPI-M)
DEWEK 2008, Bremen 26.11.2008
Introduction
IPCC (Intergovernmental Panel on Climate change)
has defined scenarios depending on:
• demographic development
• socio-economic development
• technological change
• heterogeneity of world
population
• global or regional solutions for
challenges
Implement these changes as emission
scenarios for greenhouse gas concentration
(SGA / M&D / MPI-M)
DEWEK 2008, Bremen 26.11.2008
Regional model, data base
Regional model: CLM (Climate Local Model, based on
weather forecast model of German Meteorological Service)
CLM is embedded in global
model ECHAM5/MPIOM,
is initialized at 1960
global model:
ECHAM5-MPIOM
Is forced by global model data
throughout the simulation at the
boundaries
CLM builds its own regional dynamical structures
(= weather) within the model region
(SGA / M&D / MPI-M)
DEWEK 2008, Bremen 26.11.2008
Regional model, data base
Model simulations:
Orography
Model region Europe
Horizontal resolution ~20 km
33 vertical levels, lowest levels:
33 m, 110 m, 220 m
‘Rotated grid’, NetCDF-format
Transient simulation
1960-2100
Climate of 20th century
1960 – 2000: C20 (3 runs)
Szenarios
2001 – 2100:
A1B (2 runs)
B1 (2 runs)
(SGA / M&D / MPI-M)
DEWEK 2008, Bremen 26.11.2008
Regional model, data base
• Output values must not be interpreted for single
grid boxes.
• Time / date must not be taken as real time / date.
• Scenarios are assumptions of how the climate
system may develop.
• Climate is variable (in model and in reality),
decadal averages are still highly variable,
therefore different realizations.
• Each model contains deficits, the global as well
as the regional model.
(SGA / M&D / MPI-M)
DEWEK 2008, Bremen 26.11.2008
Methodology
Statistical analysis is done by
•
Calculation of climatological means of wind speed on
model levels (time slices 1961-1990, 2021-2050,
2071-2100, all scenarios, all realizations).
•
Scenario projections on mean wind speed compared
to present-day wind speed (‘climate change signal’).
•
Histograms of 3 h wind speed over selected subregions (at least 20 grid boxes over rather
homogeneous terrain) and 30-year time slices.
•
Histograms of differences of 3 h wind speed.
•
Caution: figures partly show 10 m wind speed on regular grid and for
2021-2050 and partly wind speed on model levels and for early 21.
century time slice 2001-2030.
(SGA / M&D / MPI-M)
DEWEK 2008, Bremen 26.11.2008
Methodology
For present-day and future climate data analysis we define subregions over Europe covering at least 20 model grid boxes:
North Sea area off the Frisian Islands
Northern Germany near North Sea coast
Middle German Low Mountains
Southern Baltic Sea
South-western highlands of Iberian peninsula
Aegean Sea
(SGA / M&D / MPI-M)
DEWEK 2008, Bremen 26.11.2008
Climatological averages
3 realizations of present-day climate
(10 m wind speed)
Similar structure
Regional wind systems visible:
Mistral, storms in Northern Atlantic,
Aegean Sea.
Large differences between sea and
land (realistic over sea?), sharp
transition.
Average annual mean of wind speed
in Northern Germany: 4-5 m/s.
Comparison with data set for
Germany (DWD) gives differences of
up to ±1 m/s.
(Walter et al., Meteorol.Z., 15, 2006)
(SGA / M&D / MPI-M)
DEWEK 2008, Bremen 26.11.2008
Climatological averages
2021-2050 –
1961-1990
A1B_1 – C20_1
(left)
A1B_2 – C20_2
(right)
Climate change signal for 10 m wind speed shows slight
- increase for northern Europe (~0.1 m/s)
- decrease for southern Europe (~0.1-0.2 m/s)
- increase over Baltic Sea and Aegean Sea (~0.3 m/s)
2071-2100 –
1961-1990
A1B_1 – C20_1
(left)
A1B_2 – C20_2
(right)
(SGA / M&D / MPI-M)
DEWEK 2008, Bremen 26.11.2008
Statistics of wind speed and wind speed change
Histograms show changes in
different wind speed classes
Analyse 3 h wind speed data at
33 m, 110 m, 220 m
Consider all single values
(statistics over n boxes)
Histograms have linear ordinate
up from frequency of 1% (upper
part) representing classes of most
frequent wind speed and
logarithmic ordinate (10-5 – 100)
representing seldom events (like
single storms, 10-5 = one event per
region)
Green bars:
present-day
Open black bars: scenario
(SGA / M&D / MPI-M)
DEWEK 2008, Bremen 26.11.2008
Statistics of windspeed and wind speed change
Wind speed at 110 m
for northern Germany (left)
and German Bight (right),
1961-1990 (green) and
Upper: 2001-2031
Bottom: 2071-2100
• very similar histograms
in the ‘normal’ range
• increase in wind speed
> 20 m/s at both
• Increase in low wind
speed
• no large change
between begin and end
of century
(SGA / M&D / MPI-M)
DEWEK 2008, Bremen 26.11.2008
Statistics of wind speed and wind speed change
Present-day (green) and end of 21. century
Baltic Sea: decrease of low and moderate wind
speed, increase of moderate to large wind speed
Spain: increase of
low wind speed,
decrease of wind
speed > 5 m/s
Aegean Sea: decrease of wind speed < 10 m/s
and storms > 30 m/s, increase of large wind
speed 10-20 m/s and ~30 m/s
(SGA / M&D / MPI-M)
DEWEK 2008, Bremen 26.11.2008
Statistics of wind speed and wind speed change
spring
summer
Seasonal differences in 10 m wind speed over Germany:
decrease in spring and summer, increase in autumn and winter,
but in all seasons decrease over Alps and increase over sea
autumn
winter
(SGA / M&D / MPI-M)
DEWEK 2008, Bremen 26.11.2008
Summary and outlook
Average wind speed changes in Europe are expected
to be small under future scenario conditions.
Increase over northern Europe (Germany),
decrease over southern Europe (Germany) except Aegean Sea.
Histograms of present-day show more details, e.g. increase of
strong wind over northern Germany / German Bight,
increase of low wind speed over Spain.
Seasonal differences of climate change signal for Germany:
decrease of wind speed in summer, increase in winter.
Not yet all data processed, but tendency appears to be clear.
Analysis continues …
(SGA / M&D / MPI-M)
DEWEK 2008, Bremen 26.11.2008
(SGA / M&D / MPI-M)
DEWEK 2008, Bremen 26.11.2008
Statistics of windspeed and wind speed change
German midlands:
Increase of low wind speed (< ~5 m/s)
Decrease of moderate to high wind
speed (5 – 15 m/s)
Increase of strong winds > 15 m/s
i.e. more extreme values
(SGA / M&D / MPI-M)
DEWEK 2008, Bremen 26.11.2008
M&D Technical Report about CLM-Simulationen:
http://sga.wdc-climate.de/news
Contact and Information
Service Gruppe Anpassung - SGA:
Internet: http://sga.wdc-climate.de
email: [email protected]
Climated data base WDCC:
http://wdc-climate.de
CERA data base:
http://cera.wdc-climate.de
(SGA / M&D / MPI-M)
DEWEK 2008, Bremen 26.11.2008
Rotierte Länge und Breite (blaue Linien) für ein sphärisches Koordinatensystem mit
dem Nordpol am Punkt PN mit den geographischen Koordinaten
N=162°W und N=39,25°N.
Orange Linien: Länge und Breite des unrotierten geographischen Systems.
(SGA / M&D / MPI-M)
DEWEK 2008, Bremen 26.11.2008
Regional model, data base
Data are available from CERA database (Model & Data, MPI-M)
http://www.mad.zmaw.de/
CERA-Portal
WDCC
Experiments
Only data transformed to pressure levels or interpolated
near-surface data (wind speed at 10 m, 2 m temperature, ..)
(SGA / M&D / MPI-M)
DEWEK 2008, Bremen 26.11.2008
Statistical Analysis, histograms
(SGA / M&D / MPI-M)
DEWEK 2008, Bremen 26.11.2008