出版社:Centro de Estudos Geográficos, University of Lisbon
摘要:THE USE OF STABILITY INDICES IN THE STUDY OF CONVECTIVE SITUATIONS: THE CASE OF 1997 AUTUMN STORMS, IN LISBON - The autumn of 1997 in Portugal was remarkable for the occurance of several situations of storms, some of them with tragic consequences, as they caused floods with casualties and enormous damages. In Lisbon, four heavy rainfall events accurred from the 18th October to 3rd November and we want to investigate the thermodynamic condtions of these severe storms to deepen our knowledge of these situations with regard to climate. For this purpose, several stability indices communly used in thunderstorm forecasting were calculated. We concluded that they are useful to measure the degree of instability of certain atmospheric situations, bur more applications must be made in order to define some significative thresholds for the indices concerning southern Portugal.