Padrões térmicos no alto vale do Zêzere. Condicionantes topográficas e meteorológicas

Finisterra - Revista Portuguesa de Geografia

卷:XLIV

关键词: Temperature patterns;    Air temperature;    Local climate;    Serra da Estrela;    Thermal inversions.;   

DOI  :  

来源: DOAJ

【 摘 要 】

Air temperature patterns in upper Zêzere Valley (Serr a da Estrela, Portugal). The influence of topogr aphy and meteorology – A networkof air temperature data loggers was installed in the Serra da Estrela with the objective of studying the main air temperature patterns. Data was collected at 2-hour intervals during 2000. A k-means analysis was used to classify the air temperatures and 4 typesof patterns were identified. Patterns 1 and 4 that occurred in 34% of the records show cold air accumulation on valley floors. In Patterns 2 and 3 air temperature decreases with altitude (66 %). The control effect of the geographic and meteorological factors on the 4 temperature patterns was evaluated using one-way ANOVA. The results show that patterns 2 and 3 are related to unstable atmospheric conditions, with high wind speed and air humidity, and more intense vertical movement of the air (negative omega). On the contrary, the other two patterns are related to more stable atmospheric conditions (1 and 4). The more significant variables from the ANOVA were chosen for the discriminant function analysis. The results model correctly 74% of the cases. The first function (71%) discriminates nocturnal from diurnal events and the second (41%), the atmospheric stability. The results evidence the effect of the morphology in the air temperatures and similar results are to be expected in mountains with comparable topographical and climate conditions. Knowledge of the shadow effect induced by the valleys and its repercussions on the maintenance of the cold air pool in the morning in N-S oriented valleys (pattern 4) is especially significant for planning and environmental impact assessment studies.

【 授权许可】

Unknown