CLIVAR’s Variability of the American Monsoon Systems Panel (VAMOS) 2001: “VAMOS is based on two internationally coordinated monsoon experiments: MESA in South America and NAME in North America.” 2009: The term "monsoon system" encompasses not only the summer monsoon rainfall in the tropical Americas, but also the perturbations in the planetary, synoptic and mesoscale flow patterns that occur in association with it, including those in the winter hemisphere. The region of interest covers both the tropical and the extratropical Americas and surrounding oceans.

Variability of the American Monsoon Systems (VAMOS) The annual cycle of convection over the Americas Horel et al. (1989) IASCLIP

VAMOS (2009) CLIVAR and GEWEX endorsed activity: - La Plata Basin Regional Hydroclimate Project Cross-cuts: - Modeling - Extremes - Anthropogenic Climate Change - Decadal Predictability Four Complementary Science Programs North American Monsoon Experiment (NAME) Monsoon Experiment for South America (MESA) VAMOS Ocean Cloud Atmosphere Land Study (VOCALS) Inter-Americas Study of Climate Processes (IASCLIP)

The North American Monsoon Experiment D. Gochis, May 13, 2009 Outstanding Questions and Remaining Challenges: Predictions: Clear lack of predictability of many large-scale modes for long-lead pred. Clear lack of predictability of many large-scale modes for long-lead pred. Need for improved downscaling methods for improved short-lead seasonal and medium range predictions Need for improved downscaling methods for improved short-lead seasonal and medium range predictions Resolve the failure of free running coupled OAGCMs to realistically represent key features of the NAM hydroclimate Resolve the failure of free running coupled OAGCMs to realistically represent key features of the NAM hydroclimate Develop a process-based consensus on climate change impacts on NAM Develop a process-based consensus on climate change impacts on NAM

HYPOTHESIS: The SAMS provides a physical basis for determining the degree of predictability on short- and long timescales over the region. Monsoon Experiment in South America (MESA) Monsoon Experiment in South America (MESA) Chair: J. Marengo Selected MESA deliverables: More comprehensive understanding of South American climate variability and predictability; Strengthened multinational scientific collaboration; Improved observing system design for monitoring and predicting the South American monsoon system; Measurably improved weather and climate models that predict South American monsoon variability.

VAMOS Ocean Cloud Atmosphere Land Study (VOCALS) GOALS of VOCALS Improved understanding and regional/global model representation of aerosol indirect effects over the Southeast Pacific Climate System. Elimination of CGCM systematic errors in the SEP, and improved model simulations of the coupled system in the region and global impacts of its variability Universities 20 Research Institutions 6 Operational centers

The VOCALS Regional Experiment (REx) off the Chilean Coast was completed in Oct-Nov 2008 A four-part report with Rex information put in VOCALS web site ( ) Second VOCALS Meeting: July 2009, Seattle, Washington Data analysis and modeling continues in several centers.

5 largest warm pools 5 smallest warm pools (i)What are the sources and predictability of summertime anomalies in the WHWP? (ii) What are the structure and dynamics of the regional atmospheric circulation and low-level jets? (iii)How does this flow depend on and interact with boundary conditions such as the WHWP, land heating, and topography to modulate precipitation and storms? Within this climate setting, how can predictions of important weather phenomena such as tropical cyclogenesis events within the region be improved? IASCLIP main science issues IASCLIP Links IASCLIP–NAME Great Plains Precipitation IASCLIP-VOCALS Boreal summer circulation IASCLIP-MESA Boreal winter circulation

La Plata Basin research networks CLARIS - LPB A Europe-South America Network for Climate Change Assessment and Impact Studies IAI - LPB Ecosystems, Biodiversity, Land Use and Cover, and Water Resources Multiple Regional Projects

CLARIS LPB countries, 20 institutions - Subproject 2: Past and future hydroclimate Subproject 4: Socio-economic scenarios and adaptation/ prevention strategies · WP3: Improving our description of recent past climate variability in La Plata Basin · WP4: Hydroclimate past and future low-frequency variability, trends and shifts · WP5: Regional Climate Change assessments for La Plata Basin · WP6: Processes and future evolution of extreme climate events in La Plata Basin · WP8: Land use change, agriculture and socio-economic implications · WP9: Water resources in La Plata Basin in the context of climate change Courtesy of Anna Sorensson

Cross-cut: The VAMOS Modeling Plan Publications/Vamos_Modeling_Plan_Jun08.pdf Ben Kirtman, Celeste Saulo and others

Improve the prediction of warm season precipitation over the Americas, for societal benefit, and to assess the implications of climate change. The VAMOS modeling plan seeks improvements to how we model the interactions between the local processes and regional and larger scale variability in regional and global models. Model development efforts must take on a multi-scale approach that integrates across all of the [ science programs in VAMOS and, on the global scale, link with the wider modeling initiatives in CLIVAR and WCRP. [ Objectives

1. Introduction 2.Modeling Strategy: A Multi-Scale Approach 3. Representation of monsoon processes for improving prediction A) Simulating, Understanding and Predicting the Diurnal Cycle B) Predicting the Pan-American Monsoon Onset, Mature and Demise Stages C) Modeling and Predicting SST Variability in the Pan-American Seas D) Improving the Prediction of Droughts and Floods 4.Data assimilation, Analysis and Assessing Observing Systems 5.Prediction and Global-scale Linkages VAMOS modeling plan Publications/Vamos_Modeling_Plan_Jun08.pdf

Prediction issues –Role of SSTs (especially other than ENSO) –Role of land surface feedbacks (strength, time scales) –Role of intraseasonal variability (e.g. MJO) –Seasonal and Decadal differences in predictability –Current Level of Quality

VAMOS Extremes Task Force co-chaired by Lisa Goddard and Jean-Philippe Boulanger (2008/9)* VAMOS will consider its continental perspective in linking extremes in warm season climate behavior to the circulation structures defined as the monsoon systems. * Siegfried Schubert and Iracema Cavalcanti (TBC) The VAMOS Extremes Task Force considered: (1) Issues that are coherent across VAMOS program areas, (2) Aspects of extremes that can be somewhat unique to VAMOS, and (3) How to capitalize and complement existing and on-going efforts within the climate community (e.g., USCLIVAR; CEOP). (4) Social impact of extremes: seeking to quantify the cost of specific extreme events

VAMOS Anthropogenic Climate Change task force Tereza Cavazos, Dave Gochis, J.-P. Boulanger, J. Marengo nn In the climate change context, there is a need to identify and understand important processes that control monsoonal climates in the Americas, their variability and changes, and how these processes interact with broader societal issues, such as impacts, vulnerability and adaptation. Challenges Assessment of GCM model performance and uncertainties Improvement of the simulation and understanding of major tropical and monsoon-related modes of variability Investigation of the role of aerosols, land cover and land use on the radiative balance and hydrological processes Development of detection and attribution studies Regional climate downscaling for integrated assessments of climate change

Regional impact assessment studies Regional impact assessment studies Basic Needs Observations of sufficient detail and scope are required to improve validation, models and model ensembles and to ensure that monsoon-related processes can be adequately elucidated, predicted and projected Improve or create regional databases that include observations, GCM model simulations, and regional downscaling simulations at daily and monthly timescales of the American monsoon regions

North American Regional Climate Change Assessment Program (NARCCAP) Assess regional climate change for North America by downscaling 4 AOGCMs with 6 RCMs. Each RCM downscales two AOGCMs Standard output format similar to AR4/CMIP3, downloadable from the Earth System Grid (ESG). Project phases and status: Phase I: RCMs driven by reanalysis ( ) to examine uncertainty in RCMs (completed) Phase IIa: RCMs driven by AOGCM output for 20th century ( ) (nearing completion) Phase IIb: RCMs driven by AOGCM output from SRES A2 scenario ( ) (nearing completion)

Current climate or Scenario NARCCAP Design GFDL CCSM HadCM3 CGCM3 Provide boundary conditions MM5 Iowa State RegCM3 UC Santa Cruz, ICTP MRCC U. Quebec, Ouranos HadRM3 Hadley Centre RSM Scripps WRF NCAR/ PNNL global climate models regional climate models

CLARIS-LPB Regional climate change assessments WP5 specific objectives: ● Coordinate efforts to produce ensembles of the regional models toward an integrated view of the expected regional hydroclimate in South America in general and La Plata Basin in particular. ● Investigate the range of differences between the projections employing a suite of mesoscale regional models. ● Contribute to the knowledge of downscaled climate model scenarios for the La Plata basin region, and quantify their associated uncertainties.

CLARIS-LPB WP-5 Regional climate change and downscaling - Regional climate model scenarios (BCs: A1B) (ERA-Interim), GCMs Metrics Specific deliverables are: 5.1: A set of metrics to be employed in model performance 5.2: Uncertainties in simulations from Task 1 will be examined and reported.

WCRP CLIVAR SSG May 2009 Madrid, Spain Jim Hurrell, Co-Chair, International CLIVAR SSG Selected CLIVAR Priorities Anthropogenic Climate Change Natural variability versus forced change Climate sensitivity and feedbacks Regional phenomena Extremes Decadal Variability, Predictability and Prediction Intra-to-Seasonal Variability, Predictability and Prediction Monsoons (and ENSO, TAV, …) ISV/MJO …

WCRP CLIVAR SSG May 2009 Madrid, Spain Jim Hurrell, Co-Chair, International CLIVAR SSG Improved Atmosphere and Ocean Components of ESMs Analysis and Evaluation “Climate Process Teams” (process studies) Capacity Building Summer schools Topical workshops Expert training

In summary: VAMOS can contribute with its regional expertise to advance CLIVAR’s Imperatives… VAMOS promotes communications between science components, Cross-cuts, Research networks… VAMOS is interested in increasing and strengthening the links with USCLIVAR and other Climate Programs…