Estimation of evaporation rates in the Southern Red Sea based on the AVHRR sea surface temperature data

الملخص EN

Dalton's equation is used to study the evaporation in the southern Red Sea.

Evaporation is estimated for three regions; (A) Jeddah, (B) Jazan and (C) Hodeidah (Yemen).

The annual averages of evaporation for Jeddah, Jazan and Hodeidah are 2.04, 1.29 and 1.25 m/yr respectively.

In Jeddah region, the evaporation rate is higher than those of Jazan and Hodeidah.

Evaporation is higher in Jeddah during November, December and January, while it is higher in Hodeidah region in the month of October.

In Jazan evaporation rate is higher in July.

The correlation between the humidity gradient (ew-ea) and monthly average of evaporation is strong in all regions being approximately 0.8, whereas the correlation between monthly average of evaporation and wind speed is about 0.5.

The main cause of higher evaporation is the humidity gradient (ew-ea) i.e.

higher humidity gradient.

In Jeddah region higher annual average evaporation is observed during 2000 and 2006 with lower values in 2004 and 2005.

In Jazan evaporation is higher in 1999 and lower in 2002 whereas in Hodidah the higher values are observed in 2006 and the lower values in 1999.

These variations are related to the changes in humidity and the wind speed at these locations.