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Analysis of extreme events variability and quantification of model uncertainties
LABORATORIO DE EXTREMOS CLIMÁTICOS EN SUDAMÉRICA Matilde Rusticucci, Olga Penalba Assistant Researchers: Mariana Barrucand, María Laura Bettolli Post-Doc: Bárbara Tencer, Madeleine Renom, PhD Students: Federico Robledo, Natalia Zazulie, Juan Rivera, Vanesa Pántano, Gustavo Almeira Laboratorio de Extremos Climáticos de Sudamérica Departamento de Ciencias de la Atmósfera y los Océanos- FCEN- Universidad de Buenos Aires / CONICET LABORATORIO DE EXTREMOS CLIMÁTICOS EN SUDAMÉRICA
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Extreme Temperatures ETCCDI
October - March Extreme Temperatures ETCCDI Linear trend Cold Days MAX TEMP 10th perc. Warm Days MAX TEMP 90th perc. April-September Cold Days MAX TEMP 10th perc. Warm Days MAX TEMP 90th perc. Barrucand, PhD thesis
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Penalba, Bettolli; Robledo; Rivera; . Pántano
Tucumán Temporal Variability November WET CONDITION Monthly accumulated extreme rainfall greater than 75th daily percentile . December Salta DRY CONDITION Annual Amount of Dry days Index Penalba, Bettolli; Robledo; Rivera; . Pántano
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Spatial distribution of return periods - 1956-2003
Observed Changes in Return Values of Annual Temperature Extremes over Argentina Matilde Rusticucci And Bárbara Tencer Journal Of Climate Volume 21 HTx 40ºC HTn 25ºC LTx 6ºC LTn -5ºC Spatial distribution of return periods
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GEV observed (black ) ERA-40 (solid black ) and GCMs. GEV ( - - -) (solid )
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Covariability between daily intensity of extreme rainfall (DIER) and Sea Surface Temperature
Second mode 17% (Singular Value Descomposition) Austral Spring SON DIER correlation of the second mode
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De-trended annual time-series (blue) and smoothed with a 10-year running mean (red) of indices
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Interdecadal changes in the relationship between extreme temperature events in Uruguay and the general atmospheric circulation.Madeleine Renom , Matilde Rusticucci , Marcelo Barreiro accepted in Climate Dynamics, 2011) Summer Cold nights Cold days Warm nights Warm days
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Regressions maps of TN10 onto, for summer.
SLPa the negative phase of the SAM is associated with more frequent cold nights No relationship at all with the SAM. vector wind at 925 hPa. vector wind at 200 hPa
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Frost Days 1961-2000 mean Models overestimate
Figure 2: The same as Figure 1 except for FD: number of days where the minimum temperature was below 0ºC
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R10 1961-2000 mean Models overestimate Models underestimate
Figure 3: The same as Figure 1 except for R10: number of days where the precipitation was over 10 mm/day.
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Part 2: historical trends
TN90 R10 CDD
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TN90 % 1960 1965 1970 1975 1980 1985 1990 1995 2000 R10 Days 1960 1965 1970 1975 1980 1985 1990 1995 2000 CDD Days 1960 1965 1970 1975 1980 1985 1990 1995 2000
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TN90 % 1960 1965 1970 1975 1980 1985 1990 1995 2000 R10 Days 1960 1965 1970 1975 1980 1985 1990 1995 CDD Days 1960 1965 1970 1975 1980 1985 1990 1995 2000
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Daily circulation patterns in Southern South America
Observed Circulation Types (CT) and percentage of days corresponding to each group during austral summer. DJF CT2 CT4 With the`purpose to evaluate how much rainfall information for the core crop-producing region is contained in the circulation structures at regional scale. 19% 26.8% highest contribution to heavy rainy days in the Pampas (blue square) highest contribution to dry days in the Pampas (blue square) Daily mean sea level pressure (SLP) fields
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Evaluation of the capacity of a set of GCMs to reproduce these atmospheric structures
26.8% CT4 19%
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Projected changes at different time horizons of 21th century
Frequency (%) of CTs for summer for NCEP (red diamond), GCMs (circles) and ensemble of GCMs (blue diamond). 20th Century Anomalies of the frequencies of the CTs with respect to 20th Century in two horizons.
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Estimate the frequency of extreme events in the coming years
Future plans: Evaluate the relevance of the decadal variability in the occurrence of extreme events Analyze the physical processes involved in the occurrence of extreme events Assess the ability of global models to reproduce the observed decadal variability of extreme events Contribute to greater understanding and prediction of future climate extremes. Estimate the frequency of extreme events in the coming years Matilde Rusticucci, Olga Penalba Assistant Researchers: Mariana Barrucand, María Laura Bettolli Post-Doc: Bárbara Tencer, Madeleine Renom, PhD Students: Federico Robledo, Natalia Zazulie, Juan Rivera, Vanesa Pántano, Gustavo Almeira Laboratorio de Extremos Climáticos de Sudamérica Departamento de Ciencias de la Atmósfera y los Océanos- FCEN- Universidad de Buenos Aires / CONICET
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