1. On the simulation of regional climate in South America with emphasis on extremes and surface processes Claudio Menéndez, Andrea Carril, Anna Sörensson, Romina Ruscica, Pablo Zaninelli CIMA 25 April 2011, 2nd UMI-IFAECI Meeting

2. Recent and ongoing activities 1. Analysis of large scale variability influencing the regional climate 2. Evaluation and intercomparison of climate simulations at the regional scale 3. Study of land surface–atmosphere interactions 25 April 2011, 2nd UMI-IFAECI Meeting

3. 1. Analysis of large scale variability influencing the regional climate To what degree can we relate the regional changes in variability/extremes to changes in the large scale atmospheric circulation? How does anthropogenic climate change influence the likelihood of occurrence of extreme weather/climate phenomena? Recent and ongoing work: IPCC AR4/CMIP3 models  Influence of the SAM on extreme indices (Menéndez & Carril, 2010, Climatic Change) Data sets from different reanalyzes (e.g. 20CR, ERA40) + AGCM experiments + other available “long” simulations  (e.g.) Influence of tropical SST anomalies on the regional variability (including extremes) 25 April 2011, 2nd UMI-IFAECI Meeting

4. “ENSO flavor” experiment 7 x 30 yr simulations with ECHAM4 (carried out by A. Cherchi at CMCC, Italy) Control: climatological SST 3 El Niño-like runs: climatological SST +idealized positive anomalies over the tropical Pacific 3 La Niña-like runs: climatological SST +idealized negative anomalies over the tropical Pacific Ongoing collaboration with Italy (CLARIS LPB)25 April 2011, 2nd UMI-IFAECI Meeting

5. Exploring temperature extremes in different data sets Cold nights (25 th perc Tmin)Warm days (75 th perc Tmax) e.g. 20CR reanalysis December March (P. Zaninelli) Fraction of days in 1980-2000 exceeding the 75th percentile of Tmax in 1960-1980 Fraction of days in 1980-2000 not exceeding the 25th percentile of Tmin in 1960-1980 25 April 2011, 2nd UMI-IFAECI Meeting

6. 2. Evaluation and intercomparison of climate simulations at the regional scale How do we assess models performance in a region with (high) uncertainty in the observations? How the models reproduce the climate of the region and its variability in a climate change context? What skills do models need to be considered useful for different applications? Recent and ongoing work: Assessment of 6 RCMs for simulating different month-long “extreme” periods (Menéndez et al., 2010, Climatic Change) Assessment of regional climate change simulations (RCA3 driven by ECHAM5-OM, Sörensson et al., 2010, Meteorol. Z.) CLARIS-1 multi-model ensemble 1991-2000 (Carril et al., submitted) Participation in CLARIS LPB

7. CLARIS-1 multi-model ensemble 1991-2000 maximum temperature DJF 75th PERCENTILE Region: SESA (Carril et al., submitted) 25 April 2011, 2nd UMI-IFAECI Meeting

8. CLARIS-1 multi-model ensemble 1991-2000 maximum temperature DJF 75th PERCENTILE LMDZ OBS ENS Region: SESA (Carril et al., submitted) 25 April 2011, 2nd UMI-IFAECI Meeting

9. CLARIS-1 multi-model ensemble 1991-2000 precipitation DJF DJF MEAN, all South America (Carril et al., submitted) CRU CMAP “OBSERVATION UNCERTAINTY” ENSEMBLE BIAS ENS - CRU But verification with different datasets leads to different results… 25 April 2011, 2nd UMI-IFAECI Meeting

10. 17 April 2011, 2nd UMI-IFAECI Meeting 3. Study of land surface–atmosphere interactions Are there particular regions of strong interaction soil moisture-atmosphere in southern South America? Recent and ongoing work: We identified parts of LPB as a region of potentially strong coupling between soil moisture, evapotranspiration and precipitation through experiments with RCA (e.g. Sörensson & Menéndez, 2011, Tellus A). To explore the influence of these interactions on the variability of precipitation (including occurrence of heavy precipitation) Incorporation of dynamic vegetation into RCA for South America is planned 25 April 2011, 2nd UMI-IFAECI Meeting

11. Summer soil–evapotranspiration-precipitation coupling in South America Evaluating the degree of soil moisture - atmosphere interaction, using ensembles of simulations performed with a regional climate model (RCA3) Sörensson & Menéndez, 2011, Tellus A Koster et al., 2003, Exchanges: 25 April 2011, 2nd UMI-IFAECI Meeting

12. Exploring soil moisture-precipitation coupling R. Ruscica 25 April 2011, 2nd UMI-IFAECI Meeting Anomalies of top soil moisture horizontal gradient, “day -2”

13. Standard Deviation of precipitation (ensemble S – ensemble W) in two different time-scales: daily and 6-day mean precipitation Rainfall variance forced by soil moisture R. Ruscica 25 April 2011, 2nd UMI-IFAECI Meeting

14. RCA3 coupled to the dynamic vegetation model LPJ-GUESS  RCA-GUESS A. Sörensson & P. Samuelsson 25 April 2011, 2nd UMI-IFAECI Meeting

16. 17 April 2011, 2nd UMI-IFAECI Meeting Exploring synergies with scientists from other disciplines… Sörensson & Menéndez, 2011, Tellus A Examples during the last year: Exchange of ideas and information of common interest with colleagues from Biological Sciences and Ecology (Pedro Flombaum) Sea temperature affects fishing  Cold conditions negatively affect the fishing industry in Argentine waters. Is there any relation with the dominant modes of variability in the climate system (ENSO, SAM) ? (collaboration with INIDEP, CONICET) Project on adaptation to climate change with social scientists and different partners (including Red Cross and government entities) (International Research Initiative on Adaptation to Climate Change, Canada)

17. 17 April 2011, 2nd UMI-IFAECI Meeting “ENSO flavor” experiment Ongoing collaboration with Italy (CLARIS LPB)