Extended Abstract (2.7M)10.5
Heat waves in the Mediterranean Region: Analysis and model results
Marina Baldi, IBIMET/CNR, Rome, Italy; and M. Pasqui, F. Cesarone, and G. De Chiara
Heat-wave events have a high cost in terms of damage to the agriculture, forest-fires, and, also, in term of human health and death loss. Initial estimates of the economic loss (more than $13 Billion) place the summer 2003 European heat wave on top of all natural disasters of the year. In this respect, these events represent one of the worst weather-related cathastrophy, therefore an appropriate forecast leading to an efficient early warning systems (EWS) is highly desirable. Heat-waves are a familiar feature of the Mediterranean summer. Several anomalous warm summers occurred in the Mediterranean and southern Europe in the last 30 years, with heat-wave events of different intensity and length. However, the heat-wave occurred in 2003 (the most extreme in 500 years) was the longest and warmest event occurred, with more than 30,000 fatalities in Western Europe, and it has been viewed by some Authors as part of the expected global signal of warming. It is arguable that resulted from a direct of lower tropospheric global warming, or more likely, it has been a regional climate event. In an attempt to support this last hypothesis, we examine the recent 30 summers in the Mediterranean and south Europe region. We analyse the climatology and the anomalies and we extract the length and the intensity of the regional heat-waves. In relation to these events we examine recurrence of the anomalies of the south Asian monsoon, West African monsoon, and of the SSTs in selected areas: the gulf of Guinea, El Nino-3 and Indian ocean, in order to explore the qualitative-quantitative links between the Mediterranean heat-waves and other larger scale climate features. We also check the hypothesis that regional features, such as large soil moisture deficits, accrued in the region due to an exceptionally early and warm spring, may have intensified the subsequent summer heat waves. Surface observations are used to identify the events, and to quantify their intensity, and finally to classify them (short and long lasting). The NCEP-NCAR Reanalysis have been extensively used to quantify the extent and significance of the global and regional atmospheric anomalies in causing these periods of extreme heat, and find patterns associated and/or preceding the Mediterranean heat-waves. In particular, as a case study, we analyze the summer 2003 heat-wave event, being not only the longest and warmest detected, but also the most damaging and costly, using NCEP/NCAR reanalysis and multiple datasets. We also show results from simulations of this particular event obtained using RAMS (Regional Atmospheric Modelling System) in order to capture the mechanisms giving rise to such anomalous episode, and to understand how to improve the forecast of these extreme events, as needed for an efficient early warning systems. Analysis and model results show that heat waves in western Europe and Mediterranean are regional climate fluctuation, weakly linked to large scale climate events, as monsoons and SSTAs, rather than a direct result of lower tropospheric global warming, which, however, may play a role in enhancing their strength.
Session 10, Climate Modeling Studies 2 (parallel with Session 11)
Wednesday, 12 January 2005, 1:30 PM-5:30 PM
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