Transcript Slide sem título

Foreign &
Commonwealth
Office
Performance of the HadRM3P model for downscaling of
present climate in South American
Lincoln Muniz Alves*, José A. Marengo*
*Centro de Previsão de Tempo e Estudos Climáticos (CPTEC/INPE)
12630-000 Cachoeira Paulista, São Paulo, Brazil (Contact: [email protected])
SKILL OF THE MODEL SIMULATION
SCIENCE GOAL
A regional program led by CPTEC/INPE is CREAS (Regional Climate Change
Scenarios for South America). CREAS represents a collaboration between the
UK-Met Hadley Centre Regional and various programs from the Brazilian
government funded by GEF. In CREAS, the HadAM3P global model is used
together with the HadRM3P regional model to downscale climate variability and
change in South America at the resolution of 50 km. In this poster, we analyze
simulations of climate variability for South America during the present (1961-1990),
at the annual and seasonal levels.
EXPERIMENTAL DESIGN
Factors to consider
Setup
Research Components
- Simulation length
- Ensembles
- Spin up
- Choice of domain
- Resolution
- Output data
- Surface configuration
- 31 years (Jan/1960 to Dec/1990)
- Three members
- 1 year spin-up
- South America
- approximately 50Kmx50Km
- standard diagnostics: daily
- standard
Brier Skill Score of the RCM for various
rainfall indices in several regions.
Model validation:
- Assessing the consistency
between the RCM and GCM
- Assessing how well the RCM
represents the present day climate
Climate change scenario construction:
- To generate high resolution
climate change scenarios for use in
climate impacts and adaptation studies.
CONTROL CLIMATE SIMULATED BY THE RCM
Anomaly correlation, considering the ensemble
mean. Precipitation (top) and Temperature
(below)
How far does the RCM diverge from its driving AGCM (HadAM3P)?
How HadRM3P add value to the AGCM?
OBSERVATION
HadRM3P
Above area - 0.57
Below area - 0.60
1985
wind field at 200hPa
wind field at 200hPa
NWP-E
Table - Bias, standard deviation (STD), root mean square error
(rmse) and correlation coefficient () of annual cycle.
Temperature
Above area - 0.78
Below area - 0.67
SUMMARY AND CONCLUSIONS
REGIONAL CHARACTERISTICS AND TIME VARIABILITY
NAm
Above area - 0.50
Below area - 0.50
Hit rates versus false-alarm rates for seasonal area-averaged
rainfall at the peak season for selected regions. Results are
shown for the simulation of rainfall above (gray) and below
(black). The area beneath the ROC curves is indicated also for
above and below precipitation
wind field at 850hPa
wind field at 850hPa
Above area - 0.60
Below area - 0.72
Simulated precipitation, temperature and atmospheric circulation at 850 and 200 hPa for DFJ 1983 and 1985.
HadAM3P (first column), HadRM3P (center), Observed (third column).
Regions of the SA
Above area - 0.33
Below area - 0.45
OBSERVATION
Temperature (ºC)
Temperature (ºC)
1983
HadAM3P
Precipitation (mm/dia)
HadRM3P
Precipitation (mm/dia)
HadAM3P
Above area - 0.33
Below area - 0.40
Precipitation
NNEB
SAm
SNEB
SBr-U
• In general the HadRM3P is capalbe of simulating the mean climatological
features over South America;
• The HadRM3P resolves features on finer scales than the GCM. This is
particularly clear for precipitation.
• The model is found to represent quite accurately the primary features of
observed circulation, temperature and precipitation patterns, including their
seasonal cycle and the main modes of interannual variability. But, there are
significant biases.
• The model must be adequalety tuned in order to give reliabe for climate
change, but there are a number of uncertainties and caveats associated
with the RCM´s predictions of climate change over South America.
Interannual variability of observed and modeled normalized rainfall
departures during the peak of the rainy season. Tick black line represents
the mean rainfall from the model ensemble. Thin blue lines represent each
member of the ensemble. Tick red line shows the observed rainfall
4
4
3
3
2
2
1
1
0
0
-1
-1
-2
-2
-3
Nam = Amazonia (northern)
-3
-4
-4
1989
1989
SNEB = Northeast Brazil (southern)
-3
-4
1989
NNEB = Northeast Brazil (northern)
-3
1987
-2
1987
-2
1987
-1
1985
-1
1983
0
1981
0
1979
1
1977
1
1975
2
1973
2
1971
3
1969
3
1967
4
1965
4
1963
1961
1989
1987
1985
1983
1981
1979
1977
1975
1973
1971
1969
1967
1965
1963
1961
-4
-1
-2
-2
NWP-E = Northwest Peru-Equador
-3
SBr-U = Southern Brazil-Uruguay
-3
-4
1985
-1
1983
0
1981
0
1979
1
1977
1
1975
2
1973
2
1971
3
1969
3
1967
4
1965
4
1963
1989
1987
1985
1983
1981
1979
1977
1975
1973
1971
1969
1967
1965
1963
1961
1961
Annual cycle of
observed
(CRU)
and modeled rainfall
and temperature in
several regions of
SA. Tick orange line
shows observations.
Thick black line
represents
the
mean
from
the
model
ensemble.
Others
colors
represent
each
member
of
the
ensemble.
Sam = Amazonia (southern)
-4
1985
1983
1981
1979
1977
1975
1973
1971
1969
1967
1965
1963
1961
1989
1987
1985
1983
1981
1979
1977
1975
1973
1971
1969
1967
1965
1963
1961
Acknowledgements
Temperature (ºC)
Precipitation (mm/day)
This poster is part of the a Master Degree Thesis of the first autor. We thank
WMO and CPTEC for partially grants this conference. Thanks also to the UKMet Office`s staffs for the valuable assistance. CREAS is funded by the UK
FCO-GOF Program and the PROBIO-MMA-GEF project (Brazil)