Tropical-extratropical teleconnections and impacts between the sea surface temperature of the Southern hemisphere and the daily intensity of extreme rainfall over Argentina.

ROBLEDO, FA, PENALBA, OC AND BETTOLLI, ML

Vienna, Austria

Congreso; EGU General Assembly 2010.; 2010

EGU

During the past few decades there has been considerable effort devoted to obtaining a better understanding of naturalclimate variability on interannual to interdecadal timescales. To determine the mechanisms governing theseclimatic variations, it is essential to characterize the large-scale interactions between the ocean and the overlyingatmosphere. The impact of climate variability on the environment and the economic activities mainly depends onchanges in the frequency of occurrence of extreme events. Relatively few studies on regional variability of climaticextremes are found in the literature compared to the number of studies on changes in climatic means. Small changesin the mean could produce substantial changes in the frequency of extreme events. In this work we analyzed therelation between the extreme daily rainfall in Argentina and the sea surface temperature (SST) of the SouthernHemisphere. The general analysis was performed in the period 1962-2005, using two data sets: 1) Monthly SSTfrom the Kaplan SST V2 from the NCEP/NCAR. The region of analysis comprises the Southern Oceans, from17,5º N to 90º S, and for all the longitudes and 2) high quality daily rainfall for 35 observation stations from theNational Weather Service of Argentina distributed throughout the country. Although there are more raingauges inthis region only 35 stations were deemed appropriate for the analysis with long records; less than 10% of missingdata; and continuity of records.In this work, we consider extreme dai.....................