Estimation of Net Surface Heat Flux of Eastern Harbor, Alexandria Egypt using Different Techniques

Abstract

In this study, two different techniques have been applied to estimate the net surface heat flux (NSHF) of the Eastern Harbor. The first one based on equilibrium temperature which is easy and direct way to calculate NSHF from the sea in comparison to the traditional method (Bulk aerodynamic formula). This technique is based on short wave radiation, net long wave radiation and latent and sensible heat flux. Daily variability of NSHF has been studied during winter, spring and summer 2009-2010 and winter and summer 2010-2011, the surface meteorological data were collected from Nozha Air Port and sea surface temperature using the immersed temperature sensor at NIOF site. The out put NSHF values of the two techniques have the same trend and there are high correlation between them reached to 94% in winter 2009, 87% spring 2009, 97% summer 2010, 96% winter 2010 and 98% summer 2011. This gives us a good reason to apply the first technique to get NSHF. There is more heat loss (negative NSHF) during many days of the winter season and more heat gain (positive NSHF) during spring and summer seasons. Thermal exchange coefficient varies from 6.55 (W m-2 °C-1) to 22.4 (W m-2 °C-1) and it has a direct relationship with wind speed and inverse relationship with (NSHF) and equilibrium temperature.