CLIMATOLOGICAL CHARACTERISTICS OF VERY-LOW HUMIDITY IN NORTHERN CRETEDUE TO DOWNSLOPE SOUTHERLY WINDS

In this paper an attempt is made to study the climatological character istics of very low relative humidity (below or equal to 10 per cent) i n northern Crete, especially at Heraklio, by utilizing data from a 34- year period (1956-1989). Specifically, after selecting the very low hu midity days based on a previously determined definition and the synopt ic situation with which they are associated, the following aspects wer e examined: (i) the interannual and monthly variation, (ii) the mean d uration of very low humidity occurrence on each day at Heraklio and it s monthly frequency, (iii) the mean values of the meterological elemen ts (temperature, wind, wind gusts, pressure, total and low-cloud amoun ts, and visibility) for the time of synoptic observations reporting ve ry low humidity at Heraklio and for the corresponding times of the day gust before it for both Heraklio and Tibaki, that is, on the northern and southern coasts of Crete. Also by comparing Heraklio's and Tibaki 's mean values of the meteorological elements it was possible to deter mine the contribution of the Cretan relief characteristics to the very low humidity occurrence at Heraklio.