Journal of Earth Science & Climatic Change
Open Access

Abstract

Water vapor is the most important greenhouse gas. It plays a major role in the dynamics of atmospheric circulation, radiation exchange within the atmosphere and climate variability. In this study, radiosonde data from 1985 to 2014 were used to examine the variaability of the precipitable water vapor (PWV) in central Saudi Arabia in the city of Riyadh (240 43 'N; 460 40'E, 764 m a. s. l.) over different time scales. The results revealed a clear seasonal cycle of PWV with a maximum during the summer months (June to August) and a minimum during the winter (December to February). This variation follows the mean monthly variation of air temperature. The PWV displays considerable variability at the inter-annual scale. We could not attribute the variations to the air temperature because no relationship was found between the two variables when the inter-annual variations were examined. Study of the annual variations of the PWV showed cyclic variations with a period of approximately 10 to 11 years. The two maximums and minimums were in 1996 and 2007 and 1989 and 2000, respectively. The results showed that the annual PWV values are anti-correlated with solar activity, represented by sunspot number, during solar cycles 22 and 23. The physical mechanism underlying this relationship remains unclear, in which future investigations are recommended.

Biography

Email: amaghrabi@kacst.edu.sa