New paper finds another amplification mechanism by which the Sun controls climate, via water vapor

A paper published today in Advances in Space Research finds changes in solar activity during 11 year solar cycles exert control over interannual changes in atmospheric water vapor. In turn, "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. Knowledge of the distribution of water vapor is important for understanding climate change and global warming."

The authors find precipitable water vapor shows cyclic variations of 10-11 years which are inversely correlated with the ~11 year solar cycles. Although the authors say the mechanism is unknown, perhaps there is some tie to the Svensmark theory of cosmoclimatology, which posits increased clouds [water vapor] result during periods of low solar activity, a similar inverse correlation. 

The paper potentially adds to hundreds of other peer-reviewed papers describing solar amplification mechanisms, whereby tiny 0.1% changes in solar activity during solar cycles are amplified to produce large scale effects on climate, including via effects on natural atmospheric and ocean oscillations such as the Southern Oscillation, North Atlantic Oscillation, Scandinavian Pattern,Quasi Biennial Oscillation (QBO), Indian Summer Monsoon, El Nino Southern Oscillation [ENSO], Pacific Decadal Oscillation, Madden-Julian Oscillation, and others. Other amplification mechanisms include via ozone and sunshine hours/clouds.

Time Distribution of the Precipitable Water Vapor in Central Saudi Arabia and its Relationship to Solar Activity

• A.H. Maghrabi^, , 
• H.M. Al Dajani

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. Knowledge of the distribution of water vapor is important for understanding climate change and global warming.

In this study, radiosonde data from 1985 to 2012 were used to examine the monthly, interannual, and annual variations and trends of precipitable water vapor (PWV) in central Saudi Arabia in the city of Riyadh (24° 43′ N; 46° 40′E, 764 m a.s.l.). 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 interannual scale. We could not attribute the variations to the air temperature because no relationship was found between the two variables when the interannual variations were examined. Study of the annual variations of the PWV [precipitable water vapor] 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 [precipitable water vapor] values are anticorrelated with solar activity, represented by sunspot number, during solar cycles 22 and 23. The physical mechanism underlying this relationship remains unclear. This finding is preliminary, and future investigations are recommended.

Precipitable water vapor is inversely correlated to solar activity