P2.11
Potential ENSO - related predictability of Temperature extreme situations in Argentina
Matilde Rusticucci, Universidad de Buenos Aires, Buenos Aires, Argentina
The relevance of ENSO phases on temperature extreme situations in Argentina is presented here. Warm and cold waves of Maximum and Minimum daily temperatures are analyzed from 40-year station data series. Cold waves are more persistent in northern Argentina, and in general, maximum intensity values occurred in winter in the northern regions, and during the summer in central-southern Argentina, the exception being cases of extreme cold winters having extremely cold waves, in the south. Over the Andes Mountains, intensity values present a minimum. The effect of ENSO phases is different depending on the month and the region. El Niņo could explain a warm winter in the North, while La Niņa could explain some warm winters in the South, but in general, both phases are closer to a Normal than a warm or cold months. Neither El Niņo nor La Niņa could explain by itself completely the climatic variability. Also, the variability among different La Niņa or El Niņo events are studied.
As a final objective, the risk of having extreme waves depending on ENSO is evaluated. There are some regions, like in Northeastern Argentina during October-December or in Northwestern in April-May (in La Niņa years) where extreme cold waves have high occurrence probability. The same analysis gives that when the warm waves are intended to predict In Northern Argentina winter, El Niņo is an important factor to be included.
In some cases it is possible to use ENSO phases as one but not the only predictor factor. In summary, ENSO phases have some importance in explaining extreme temperatures over Argentina. It should be necessary to explore other climatic factors for a better predictability.
Poster Session 2, Climate and Low Frequency Variability
Sunday, 4 April 1999, 2:15 PM-4:15 PM
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