Clouds and water vapor are defining elements of the Earth's atmosphere. Water vapor provides most of the greenhouse effect of the earth's atmosphere. Clouds are a major reflector of incoming solar radiation. Clouds and water vapor are both the product and driver of the motions in the atmosphere. There are also key ingradients in the interaction between the atmosphere and other components of the climate system. What determines the amount of clouds and water vapor in the atmosphere? What's their role in the climate variability? How will they respond to global warming? These are some sample questions concerning the climatic role of water vapor and clouds that I am trying to address through analyzing observational data and modeling.
Because the close association with small-scale motions in the atmopshere--bounday layer turbulence and moist convection, clouds and water vapor are difficult to simulate by climate models. Cloud feedbacks are considered as a major uncertainty in climate models by IPCC. The realism of water vapor feedback in climate models is also subject to debate.
How to better represent the effects of water vapor and clouds in climate models is also an issue that I am concerned with.
Water vapor and clouds are components of a larger picture--the earth's hydrological cycle. Addressing how the atmospheric hydrological cycle responds to global warming is a long-term goal of my research.