EFFECTS OF SOME SURFACE METEOROLOGICAL VARIABLES ON THE VARIABILITY OF COLUMNAR WATER VAPOUR

Abstract

 Atmospheric water vapour is an important greenhouse gas that significantly affects the variations of global climate

and water circulation. Homogenized climate data records from the Satellite Application Facilities on Climate

Monitoring (CM SAF) and surface observations of temperature and relative humidity from the National Centre

for Environmental Information (NCEI) are used to probe the temporal and spatial patterns of columnar water

vapour (W ) in Peninsular Malaysia from January 2002 to December 2011. The spatial and temporal distribution

of W  in the study area show an overall decreasing spatial trend in the north-south direction with higher mean

values presented during the southwest monsoon (SWM) period compared to the northeast monsoon (NEM)

season. Monthly minimum and maximum values of 43.99 and 57.20 mm are observed in Penang (north) and Senei

(south) respectively in the months of February and November. A statistical evaluation on the effects of the two

surface parameters on W  reveals the dominance of relative humidity in the two seasons across the stations. The

effect of temperature on the temporal and spatial pattern of W  is barely observed in the northern part of the

peninsular particularly, during the NEM season.

Key words:  Columnar water vapour; multilinear regression; temperature; relative humidity