Effects of cold front passage and atmospheric boundary layer stability in the estimates of spatially distributed heat fluxes in a tropical reservoir

Sensible and latent heat fluxes were estimated over a large tropical hydroelectric reservoir under cold front conditions. In situ and satellite data were used to adjust the bulk coefficients for momentum and heat exchanges between water and atmosphere and spatialize the sensible and latent heat fluxes over the reservoir. The results showed that during a cold front event the sensible and latent heat fluxes can be up to three times greater than the fluxes before and after the cold front passage. The main source of heat loss to atmosphere during the cold front passage was the evaporation (i.e. latent heat) reaching values near to 500 W m^-2. The highest values of heat loss were observed at littoral zone and some embayment of reservoir. The increase in wind speed and decrease in air temperature and humidity during the cold front event were the main factors that influenced the heat loss.