Solar activity and atmospheric water vapor

We report the results of an analysis of changes in the integral content of water vapor in the atmosphere during solar activity cycle 23. With the epoch superposition method, we analyzed the water vapor content in the atmosphere after strong Forbush decreases (35 events) and, separately, after energetic proton events (15 events). The decrease in the water vapor content in the atmosphere, occurring in a day after the start of energetic proton events and lasting for two days, has been found. For the Forbush decreases, a small increase (within the error limits) in the water vapor content is observed only for the strongest events.