DIURNAL VARIATION OF SST IN RELATION TO SEASON AND WEATHER PHENOMENA IN THE BOHAI REGION

This study investigated the relationships between sea surface temperature (SST) and weather phenomena in different seasons in the Bohai region (China). Five categories of weather phenomena were screened (i.e., fine, cloudy, foggy, rainy and windy conditions) and their relationships with the difference between air temperature and SST observed at Oil Platform A during 2003–C2010 were analyzed statistically. The effects of the difference between air temperature and SST in different weather phenomena were examined using the flux method of the atmospheric boundary layer and a formula for the difference between air temperature and SST. The results revealed diurnal variation of the difference between air temperature and SST of ?1.0 to +1.0 °C, i.e., air temperature above the sea surface is subtracted from the SST in corresponding weather phenomena in different seasons in the Bohai region. Moreover, according to the formula for the difference between air temperature and SST, wind and shortwave radiation are the most important factors in terms of the effects of SST on weather processes. In conclusion, the effects of SST on weather phenomena are manifest via the exchange of momentum and energy from sea to air. When the air temperature above the sea surface is lower than the SST, the SST helps develop mesoscale convection systems within the synoptic system through moisture and sensible heat fluxes. When the air temperature above the sea surface is greater than the SST, synoptic systems transfer heat energy into the sea through heat flux, which affects SST variation. Moreover, a mesoscale convection system will weaken if the synoptic system passes over a colder underlying surface.