DETERMINATION OF THE AMOUNT OF WATER VAPOR IN THE TROPOSPHERE OVER THAILAND USING SURFACE DATA

บทคัดย่อ

The amount of water vapor is shown by precipitable water vapor. It is calculated from the upper air data. In Thailand, the data were collected from four measuring stations located in Chiang Mai, Ubon Ratchathani, Bangkok, and Songkhla during the years 1993-2014. The relationship between the precipitable water vapor from the upper air data and the surface data obtained from a mathematical model was investigated in this paper. The result showed that the relationship had a relatively high level of reliability. The precipitable water vapor was nearly equal to the value from the model. The precipitable water vapor from 85 meteorological stations across the country was calculated from the model. The result showed that seasonal change of the precipitable water vapor was low in the dry season (November-April) and high in the rainy season (May-October). In addition, precipitable water vapor was varied along the latitudes of the stations. For low latitudes, the high value was obtained, but it was low for high latitudes.