Records of Surface Meteorological Elements and their Applications in Alexandria Eastern Harbour, Egypt

Abstract

The surface meteorological elements, namely: air temperature, wind regime (speed and direction), dew point temperature, relative humidity and atmospheric pressure were considered; to describe the general meteorological conditions over Alexandria Eastern Harbour (AEH). These conditions were then applied to calculate some important physical properties of the Harbour’s surface waters: sea surface temperature (SST), the evaporation rates and the net surface heat flux. The period of investigation extended from 01.01.2019 to 31.12.2020. The air temperature distribution over AEH reflected a seasonal variability with higher values in spring/summer and lower records in autumn/winter. The dominant wind direction was NNW with more than 40% occurrence and the average wind speed was 4.11 m/s. The inverse relationship between atmospheric pressure and air temperature was clear. The SST over the study period showed the same seasonal pattern in the air temperature. The mean daily evaporation from AEH surface water follows the pattern of air temperature variations to a considerable extent. The maximum mean monthly evaporation of 14 cm (0.14 m) occurred in July and August, while the minimum of 6 cm (0.06 m) occurred in January. This was associated with a volume loss of 0.389x106 m3 in July and of 0.171x106 m3 in January from AEH surface waters. The solar radiation (Qs) reached its maximum value in May (383 Wm-2) and its lowest value in September (258 Wm-2). The net surface heat in AEH (Qnet) showed a gain in four successive months: March-June, and a loss in the remaining period: July-September. Keywords: Alexandria Eastern Harbour