A research study (12 credits) submitted in partial fulfillment of the requirement for the degree of Master of Engineering, School of Environment, Resources and Development

Research Studies Project Report (M. Eng..) - Asian Institute of Technology, 1987

This research study was to make an attempt to classify daily air motion patterns (wind patterns) at 700 mbar level over Thailand, by objective statistical classification technique and to investigate the relation between duration of sunshine and these wind patterns. Daily (07 LST) data at four stations (Chiangmai, Ubon Rachathani, Bangkok and Songkhla) of four years (1969,1974,1975, and 1976) were used. Each year was devided into three seasons: summer monsoon (June-October), winter monsoon (November-February) and transitional period (March-May). Four most representative wind patterns in each season were found; few days remained unclassified. Association between these wind patterns and daily duration of sunshine was studied and wind patterns are shown to determine distinct distributions of sunshine duration. Certain conclusions were drawn that can be useful for judgement of availability of solar radiation, especially for applications using direct component of solar radiation, in different parts of the region. Association between the eqivalent potential temperature at 700 mbar level and daily duration of sunshine was also investigated for the summer monsoon 1969. The result is in good accordance with the findings of GARST ANG (196 7) and HARRIS (1970) that the duration of sunshine tends to increase with the equivalent potential temperature decreasing.