Water Vapor and Pollutants, Aerosol-Cloud Interactions

Clouds, to a great extent, govern the radiation balance and energy fluxes reaching Earth and have a strong impact on the hydrological cycle and freshwater distribution over the globe. Latent heat release in clouds is the energy source for atmospheric phenomena from cloud scale to global circulation. Changes in cloud microphysical and radiative properties impact weather and climate and contribute in changing climate. All of these determine the vital impact that clouds exert on all forms of life on the planet, human life included. Studies of clouds and cloud-related phenomena are an integral part of modern meteorology, providing data with direct application in weather forecasting, agriculture, environment control, air traffic control, and many other spheres of human activity. Natural and anthropogenic aerosol particles affect cloud properties and precipitation regimes and continue to be a growing field of research. A significant progress has been achieved in understanding cloud processes and aerosol-cloud interaction during last decade. At the same time some processes, especially those related to ice phase remain uncertain and require further investigation. A review of major processes related to aerosol effects and specially to aerosol-cloud interaction is presented.