RELATIONSHIP BETWEEN AEROSOL OPTICAL DEPTH AND PRECIPITATION CONSIDERING THE RELATIVE HUMIDITY AS AN INFLUENCE FACTOR

Atmospheric aerosols influence precipitation, modify the balance of Earth's energy, and alter the cloud properties. This work has been developed in the state of South Mato Grosso to study the correlation between aerosol optical depth and precipitation index, considering the relative air humidity. The monthly data of optical depth at 550 nm (AOD) come from the MODIS/TERRA sensor, and the climatological data come from CEMTEC-MS. They are considered for the period 2002-2011. The monthly values of AOD 550 nm show seasonal patterns, with minimum and maximum during the rainy and dry seasons, respectively. The monthly averages of AOD 550nm have been correlated with the records of precipitation and relative humidity for the state of South Mato Grosso. The analysis of Pearson's correlation for the monthly scales reveals that the UR may be the dominant influence factor in the relationship between AOD and precipitation. When partial correlation analyses are conducted for monthly rainfall data, most of the resulting negative correlations decrease or are insignificant. It happens when the UR is used as a controlling variable.