Trends of Climate Variables and Aerosol optical Depth in Thailand

This study analysed climate variables data in four stations over Thailand. Aerosol optical depth (AOD) obtained from Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) were also used to determine climatic trends in the areas under focus. The linear regression, Mann-Kendall trend, and Sen's slope tests were applied. Rain (R) gave higher values in July to October for most regions except in the Songkhla. Amount of R increased in all regions. Rainy season is caused by the Southwest monsoon, which is a normal occurrence in Thailand from June to September. However, this monsoon tended to begin earlier and last longer (May to October) than expected. Mean temperature (T_mean) values were found to be significantly higher from March to May and increased in all stations. The highest significant increases of annual T_mean were found in the North. There was no significant trend in annual R (Rainfall) at the 1% and 5% significance level in all stations. The AOD values were likely to increase in almost all stations. The highest significant increase of annual AOD was observed in Ubon Ratchathani.