Patrick Eriksson will hold his professor installation lecture entitled "Satellite microwave sounding and climate modelling of cloud ice".

Abstract

Clouds play a crucial role for life on Earth, they are a main factor for the radiation balance of the planet and are an essential part of the atmospheric water cycle. Satellite cloud remote sensing is traditionally performed using optical and infrared techniques. Such techniques probe primarily the top layer of the clouds, due to the strong scattering at those wavelengths. Hence, to measure interior of clouds, or bulk properties, microwave techniques are required. CloudSat, which is the first cloud oriented space-based radar launched 2006, is therefore a very important step forward.

Simulations show that passive observations are better performed in the sub-mm region, and design studies and the efforts to realise a sub-mm instrument targeting cloud parameters will be summarised. In parallel, the first dedicated tropospheric retrievals for Odin-SMR have been developed. CloudSat data were here applied in a novel manner to overcome systematic retrieval errors originating in the limited spatial resolution of passive observations. On the other hand, Odin-SMR complements CloudSat as the two satellites samples the atmosphere at different local times.

The representation in climate models of tropical ice clouds has been investigated. Diurnal cycles of cloud ice mass were estimated by combining CloudSat and Odin-SMR data, with the conclusion that models strongly underestimate the amplitude of the cycle. A more general assessment of the EC Earth model has also been performed, showing, for example, a vertical displacement of the cloud ice mass. These deficits are all connected to the treatment of deep convection in the models, and a method for studying the spatio-temporal response of such convection is in development.