Drenagem e acumulação de ar frio em noites de arrefecimento radiativo. Um exemplo no vale de Barcarena (Oeiras)

THE COLD AIR DRAINAGE DURING CALM CLEAR NIGHTS: AN EXAMPLE IN HE BARCARENA VALLEY (OEIRAS, PORTUGAL) - The cold air drainage system is a recent climatological field research in Portugal. In the valley of Barcarena, a few kilometres westward from Lisbon, it was possible to detect the intermittent flow of the cold air drainage during two calm clear nights. We came to the conclusion that the cold air lakes are formed in situ by the irradiation process and also by the accumulation of the cold air drained along the valley slopes. The rugosity of the surface and the slow down of the cold air along the slope could be responsible for the oscillations of the cold air lakes thickness