CLimatological characteristics of very low humidity in Northern Crete due to Downslope southerly winds

Abstract

In this paper an attempt is made to study the climatological characteristics of very low relative humidity (below or equal to 10 per cent) in northern Crete, especially at Heraklio, by utilizing data from a 34-year period (19561989). Specifically, after selecting the very low humidity days based on a previously determined definition and the synoptic situation with which they are associated, the following aspects were examined: (i) the interannual and monthly variation, (ii) the mean duration of very low humidity occurrence on each day at Heraklio and its monthly frequency, (iii) the mean values of the meteorological elements (temperature, wind, wind gusts, pressure, total and low-cloud amounts, and visibility) for the time of synoptic observations reporting very 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 determine the contribution of the Cretan relief characteristics to the very low humidity occurrence at Heraklio. KEY WORDS Very low humidity Fohn effect Downslope winds Crete

Significant changes in the regional climate of the Aegean during 1961–2002

“…seen only for a subset of stations. The contrast between Chania and Heraklio -both on Crete -may be due to the differing local terrain configuration, resulting in more frequent southerly winds at Heraklio (Prezerakos, 1994), or to inhomogenity in the Chania record due to a move in station location. The geographical division between stations is found for the whole data period, with a shift towards warming at later times.…”