Transcript Current and planned Project with the Regional Climate

Current and planned Project with the
Regional Climate Model
Regional climate simulations over southern
South America and sensitivity experiments
Silvina A. Solman
CIMA – CONICET/UBA
Buenos Aires, Argentina
Interest in using Regional Climate Models:
• To generate regional climate change scenarios over
southern South America to improve information on the
climate conditions under which natural and human systems
will be exposed.
• To study the sensitivity of climate to surface conditions,
mainly soil moisture and sea surface temperatures, in
particular, their impact on precipitation anomalies over
southern South America.
Regional climate change scenarios over southern
South America
1
2
•The AOGCM/IPSL global
model (France) will be used
to simulate changes in
climate due to the SRES A2
emission scenario.
• resolution of about 5º by 5º
• simulation for the period
1860 – 2100 .
•The AGCM LMDZ global model
adapted at CIMA (with a variable
horizontal resolution with a zoom
centred over South America) driven
by sea surface temperature, sea ice
and CO2 provided by the
AOGCM/IPSL model will be used to
simulate changes in climate.
• resolution of about 1º by 1º over
South America.
•Two time-slice experiments (10 yrs)
Regional climate change scenarios over southern
South America
3
• In this step a second regionalization will be performed.
The use of a regional climate model driven by boundary
conditions generated in the previous step, will provide
high resolution simulations for the particular area of
interest (Argentina).
Sensitivity of climate to surface conditions
• Sensitivity of climate to surface conditions,
mainly soil moisture and sea surface
temperatures. The focus is to what extent
soil moisture and sea surface temperature
conditions
impact
on
precipitation
anomalies over southern South America, in
terms of its interannual variability.
Regional climate simulations over southern
South America using MM5: Some preliminary
results
• Simulation of present-day summertime
climate with ´perfect´ boundary conditions:
Initial and boundary conditions from 6hourly NCEP reanalysis.
• Five 31 days simulations for January (19972001).
Ideally, the domain should be large
enough to allow full development of
internal mesoscale circulations and
include relevant regional forcings
• Horizontal resolution 60 km
• 23 vertical levels
• high-resulution planetary boundary
layer (Blackadar, 1976)
• Kain-Fritssch(1983) cumulus
convection
• explicit moisture scheme (Dudhia
1989)
• Bucket soil moisture scheme
With the present domain, the RCM
simulations do not diverge from the
analyses used to drive the model
Average precipitation for January (1997-2001) in
mm/day from Xie and Arkin (a) and MM5 (b)
(a)
(b)