Sensible and latent heat fluxes in coastal waters of dhahran, Arabian Gulf

Abstract EN

- Based on 30 years of meteorological data (1961-1990) at Dhahran and the sea surface temperature, the monthly means of sensible and latent heat fluxes in coastal waters of the Arabian Gulf are estimated using the bulk formulas.

The stability of the atmospheric boundary layer; the thermal differences between sea-air and the corresponding wind speed at 10m are considered when choosing the heat transfer coefficients.

The calculated mean annual sensible and evaporative fluxes are + 0.1 and - 133 w/ m2, respectively.

The small annual mean of sensible heat flux indicates a near balance condition between summer and winter seasons.

Maximum evaporation rate occurs in September while minimum rate in May.

The latent heat flux compares favourably with the Pan measurements at the same location.

It is concluded that the use of a constant transfer coefficient in earlier studies seems to overestimate the evaporative heat flux.

Introduction The Arabian Gulf is characterized by a negative water budget since evaporation greatly exceeds precipitation and runoff.

Being in an arid area in addition to its shallowness, the Arabian Gulf water is subjected to higher evaporation rate than any zonal water body.

Evaporation from semi-enclosed seas has been the subject of considerable studies in the recent years because of its significance in determining the salt, heat and water budgets.

Due to high evaporation in the Gulf, a horizontal pressure gradient is developed and a less dense surface water flows from Gulf of Oman into the Arabian Gulf through Strait of Hormuz (Abdelrahman and Ahmad, 1993).

Evaporation is one of the major causes for density variation along the Arabian Gulf and in turn for the density driven circulation.