The study of chlorophyll concentration behavior over southern coasts of Iran with an emphasis on the cold season of the year

The concentration of chlorophyll in marine environments indicates the quantity of photosynthetic plankton (phytoplankton),found in marine ecosystems.Phytoplankton populations are affected by weather conditions such as Sea Surface Temperature and Winds.They are also influenced by Aerosol Optical Depth (AOD),which can show the existence of dust.Moreover,there are seasonal variations and the correlation between these factors varies according to the depths.Despite the decrease in temperature and an increase in pressure on land areas during winter,which is accompanied by a decrease in strong winds, the formation of atmospheric fronts and strong winds caused the transfer of dust from susceptible springs in Saudi Arabia and the UAE and dust was transferred to it from the southern coast of the Persian Gulf. Investigating the long-term relationship between SST changes and the AOD with chlorophyll concentration on the Persian Gulf coasts as well as the Oman Sea,using daily MODIS products in the period of 2003 to 2020 demonstrates a strong correlation in coastal areas with the lowest depth.trend of SST and AOD on the both Seas is similar, along with the lowest values during the winter, while the seasonal trend show, the highest values of chlorophyll concentrations, in winter.Besides examining long-term chlorophyll concentration behavior over the Sea of Oman and the Persian Gulf, an emphasis was applied to the cold season of the year on February 17-22, 2018 for understanding the relationships between chlorophyll, AOD,and SST, showing the possibility of time delay in the correlation between sea surface temperature and optical depth of aerosols with chlorophyll concentration.