GEOF220 aims to give the students a basic knowledge of the physical processes with regard to solar and terrestrial radiation, condensation, cloud formation and precipitation and their interactions in the earth-atmosphere system.

In the radiation part of the course, the processes connected to radiative transfer of solar radiation and terrestrial radiation in the atmosphere are discussed. Here, both the spectral and the angular distribution of the radiation are discussed. Besides, a quantification of the radiative effect of the surface of our planet is given. In the course, both short wave and long wave radiation at the surface will be discussed, with special focus on spatial and temporal variations on local scale. The cloud physics part shortly introduces and repeats the thermodynamic basics and their application in atmospheric science. The concept of atmospheric stability and air parcel behaviour is introduced to describe the atmospheric forcing leading to condensation. A short introduction in aerosol particles and their function as cloud condensation nuclei is given. The chain of hydrometeor creation is described and the relevant physical processes are introduced, including the derivation of the main equations. It starts from the initial condensation and diffusional growth at aerosol particles and continues with further growth mechanisms, including the involvement of the ice phase and collision and coalesence. At the end, relevant measurement methods and instrumentation are introduced and discussed in particular with respect to measurement uncertainties.

After finishing the course, the student should be able to:

- explain the physical processes by radiative transfer of solar radiation and terrestrial radiation through the atmosphere (scattering, absorption, emission) and the effect of the surface on the radiation

- describe both the spatial and temporal variations of shortwave and longwave radiation at the surface of the Earth

- apply the basic laws of thermodynamics for the derivation of the set of equations required to describe the microphysics of condensation and droplet formation

- describe the chain of creation of hydrometeors in the atmosphere from the initial condensation on aerosol particles to falling rain and snow and explain the related physical processes

- describe the common methods and instruments for precipitation measurement and discuss the uncertainties related to those measurements

Approved exercises.

(Valid for four semesters: The semester mandatory activities have been approved and the three following semesters.)