carolina vera cima/dept. of atmos. and ocean sci. (uba-conicet) co-chair wcrp/clivar/vamos panel
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Carolina Vera CIMA/Dept. of Atmos. and Ocean Sci. (UBA-CONICET)
Co-Chair WCRP/CLIVAR/VAMOS Panel
The Monsoon Systems
of the Americas in the context of climate change
Variability of the American Monsoon Systems
WHAT ARE NAME and MESA?
The North American Monsoon Experiment (NAME) and the Monsoon Experiment South America (MESA) are two internationally coordinated efforts that aim to improve the description, simulation and prediction of the American monsoon systems, their variability, and roles in the global water cycle.
•A WCRP/CLIVAR program focused on the climate of the Americas.
• Now in its implementation phase
• Panel Co-Chairs: C. Vera (UBA, Argentina)W. Higgins (NOAA/CPC, USA)
CLIVAR Mission CLIVAR Mission To observe, simulate and predict Earth’’s climate system, with focus on ocean-atmosphere interactions, enabling better understanding of climate variability,
predictability and change, to the benefit of society and the environment in which we live.
http://www.clivar.org
CLIVAR is an interdisciplinary research effort within the World Climate Research Program (WCRP)
Monsoon mature phase
Climatological seasonal mean precipitation (shaded), 200-hPa streamlines (black contours) & vertically integrated moisture fluxes (arrows)
How well do models reproduce the annual cycle?
9-member ensemble run of the CPTEC/COLA AGCM forced by observed global SST anomalies for 1982–1991 (Marengo et al. 2003, Clim. Dyn.)
Black: Observed, Purple: ensemble mean Light blue: individual members
Annual Cycle of Precipitation
How well do models reproduce interannual variability?
9-member ensemble run of the CPTEC/COLA AGCM forced by observed global SST anomalies for 1982–1991 (Marengo et al. 2003, Clim. Dyn.)
Black: Observed, Purple: ensemble mean Light blue: individual members
Interannual variability of Precipitation anomalies
VAMOS Approach•Climate models have deficiencies in reproducing regional climate features (diurnal cycle, transient variability, etc.)
•VAMOS seeks improved understanding of the key physical processes (diurnal cycle, convection, topography, etc.) that must be parameterized for improved simulation with dynamical models.
•VAMOS modeling activities include: data assimilation, global and regional AGCM, CGCM, seasonal forecasts, hydrological models, etc.
•VAMOS employs a multi-scale approach ranging from diurnal to interannual timescales and longer.
Diurnal cycle
21Z ~ 18 LST
NAMS SAMS
21Z ~ 14 LST
South American Low-Level Jet Experiment
Enhanced precipitation
gauge network
NOAA/P-3 Missions
PIBALS Radiosondes
North American Monsoon Experiment (NAME)
NAME HYPOTHESIS:The NAMS provides a physical basis for determining the degreeof predictability of warm seasonprecipitation over the region.
The NAME 2004 Field Campaign (on going) is an unprecedented opportunity to gather extensive atmospheric, oceanic, and land-surface observations in the core region of the North American Monsoon over NW Mexico, SW United States, and adjacent oceanic areas.
Diurnal cycleWet-day hourly rain rates for various elevation bands in the SMO from the NAME Event Raingauge Network (NERN)
Time of Maximum hourly precipitation frequency from NERN
Gochis et al. 2003
Mesoscale VariabilityMCS mature stage time occurrence frequency during SALLJEX. Bars in green represent the period November 15 to December 31, in black January 1 to February 15 (Zipser et al. 2004)
Subtropical South America has the largest fractional contribution of PFs with MCSs to rainfall of anywhere on earth between 36 N and 36 S (Courtesy Nesbitt & Zipser)
05Z ~ 02 LST
Intraseasonal Variability
Typical circulation features of the NAMS accompany wet and dry surges keyed to Yuma, AZ.
(Higgins et al. 2004)
H
L
H
L
H
L
+ T. anom
- T. anom
- T. anom
+ T. anom
Typical circulation features of the SAMS accompany wet and dry conditions over Southeastern South America (e.g. Diaz and Aceituno 2003)
Intraseasonal Variability (MJO)
Composite evolution of 200-hPa velocity potential anomalies associated with MJO events and points of origin of tropical disturbances that developed into hurricanes or typhoons.
-80 -70 -60 -50 -40
-50
-40
-30
-20
-10
0
10
Interannual VariabilityRole of SST anomalies
(Doyle & Barros 2002)Role of land surface
conditions
Role of Large-scale circulation (Silvestri & Vera 2003)
ND
Precipitation
PSI(200 hPa)
Correlation coefficients between CPTEC model anomalies and observed anomalies of rainfall (Marengo et al. 2003)
Aerosol plume produced by biomass burning at the end of the dry season and transported to the south (Freitas et al. 2004)
TrendsJFM precipitation
trends (Liebmann et al. 2004)
Normalized annual departures of SALLJ-event annual counts
Precipitation River stream flow
SW Atlantic SSTs
VAMOS Contribution to GCOS Action Plan for South America
Project Brief: Enhancement of the GUAN network in Central South America
X Trinidad
X Tabatinga
The Global Climate Observing System (GCOS) was established in 1992 as a joint initiative of WMO,UNEP, IOC,UNESCO, and ICSU to provide the data necessary for climate system monitoring, climate change detection and response monitoring, application to the development of national economies, and research.
VAMOS Contribution to GCOS Action Plan for South America
Project Brief: Enhancement of Sustained Surface and Subsurface observations in western Subtropical South Atlantic
Climatological mean DJF precipitation.
Red dots: locations of the Pirata Southwestern Extension
Light blue dot: location of the proposed site for an atlas buoy.
VAMOS DELIVERABLES
• More comprehensive understanding of American climate variability and predictability;
• Strengthened multinational scientific collaboration across the Americas;
• Observing system design for monitoring and predicting the monsoon system of the Americas;
• Measurably improved climate models that predict monsoon in the Americas variability from seasons in advance.
VAMOS future challenges
• To strength links between climate variability and climate change
VAMOS WCRP-CLIVAR/WGCM IPCC
• Link between climate variability and applications
VAMOS START/AIACC in the Americas
(Big potential! Several VAMOS scientists are also AIACC Scientists already)
Thank you!
http://www.clivar.org
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