The vertical structure of clouds and their interaction with solar radiation

N. Küchler, U. Löhnert, P. Kollias and S. Kneifel

Clouds play a key role for the water cycle and for the Earth's energy budget and therefore it is important to understand cloud processes such as formation, evolution and the clouds' interactions with long and shortwave radiation. The latter is of particular importance for solar energy applications, also because the amount of installed capacity of solar energy systems has increased significantly over the last decades. Thus, accurate forecasting of incoming surface radiation has become an important tool for the energy market. However, the evaluation of forecast models and their parameterizations depend on accurate measurements of cloud properties, e.g. liquid water path or liquid water content.

To understand cloud processes and to obtain a climatological data set of cloud type and structure, several remote sensing instruments observe the atmosphere continuously at the ''Jülich Observatory for Cloud Evolution - Central Facility''. Simultaneously, radiation measurements are carried out at the ground. Combining cloud physics and radiation measurements help to understand which cloud types are most important for solar energy applications.