ผลกระทบของเอ็นโซ่ต่อการผันแปรของมรสุมตะวันตกเฉียงใต้ในรอบปีบริเวณประเทศไทย

Titleผลกระทบของเอ็นโซ่ต่อการผันแปรของมรสุมตะวันตกเฉียงใต้ในรอบปีบริเวณประเทศไทย
Publication TypeReport
Year of Publication2015
Authorsเลาหเลิศชัย จรูญ
Series Editorซัมดิน สันติ, ยะวิญชาญ สุกันยาณี, สิทธิชีวภาค กรรวี, ศุขวัฒน์ ดุษฎี
Date Published2015
Institutionกรมอุตินิยมวิทยา
Typeโครงการวิจัย
Report NumberRDG5430002
ISBN NumberRDG5430002
Keywordsมรสุมตะวันตกเฉียงใต้, ลานีญา, เอนโซ่, เอลนีโญ
Abstract

The objective of this project is to study the impact of sea surface temperature variation in the equatorial Pacific (ENSO phenomena) on the anomaly of southwest monsoon over Thailand. This is done by analyses of sea surface temperature, mean sea level pressure and wind at grid points from ECMWF and IRI data for 30 years during 1971-2000. Results show that, during May which is the transition period from summer to rainy season in Thailand, under normal conditions most of rainy seasons start around middle of May. Under El Nino condition, winds over the Andaman Sea, Thailand and the Gulf of Thailand are westerly, which cause the beginning of rainy season to be delayed. Under La Nina condition, southwest monsoon winds over the Andaman Sea, Thailand and the Gulf of Thailand are stronger than normal and El Nino conditions and cause the rainy season to begin earlier than normal. Comparing to the normal (30-year average between the years 1971-2000) it is revealed that for the years with El Nino, southwest winds over Thailand at 850hPa level are stronger than normal during the monsoon period (June to September). In the upper level at 200hPa, northeast winds are stronger than normal especially in the years with strong El Nino. For the years with La Nina the situations are reversed, southwest winds over Thailand at 850hPa level are weaker than normal during the monsoon period. While at 200hPa level northeast winds are weaker than normal especially in the years with strong La Nina. The results from data analyses show that the variation of sea surface temperature over the equatorial central and eastern Pacific affects the pattern of southwest monsoon wind over Thailand and vicinity.

URLhttp://elibrary.trf.or.th/project_content.asp?PJID=RDG5430002
Alternate TitleImpact of Inter-annual Variability of Southwest Monsoon causes by ENSO in Thailand