Thermal structure in coastal waters of central Bushehr (Iran/Persian Gulf)

273-278Thermal structure was studied in the northern coastal part of the Persian Gulf in Iranian southern province of Bushehr. Temperature measurements revealed that the morning–afternoon temperature variations were in the range of 0.2 – 4°C at deeper layers and 0.2 – 1.7°C near the sea surface. The range of the morning–afternoon temperature variations was also time dependent and reduced from a maximum value of 4°C in August to its minimum value of 0.2°C in November. Monthly average of the seawater temperature decreased about 7.4°C in the temperature decreasing period of August to November; with the maximum thermal gradient of about 3.8°C / month occurred in transition from October to November. Cross shore distribution of the sea surface temperature was almost constant. Moreover, both the maximum (36.8°C observed in August) and minimum (26.5°C observed in November) water temperatures were recorded at the surface layer, indicating that the temperature field in the study area is mainly affected by the air-sea heat fluxes. Water column was not thermally stratified at shallow waters (h < 24 m). In November, intense heat losses at the air–sea interface cause the water column become well mixed in the study area and thus, thermal stratification disappeared even at deeper waters