Natural Clouds

Clouds play a crucial role for the radiation budget of the earth. They reflect incoming shortwave (solar) radiation and modulate the outgoing longwave (thermal) radiation.  The impact of clouds on radiation is dependent on the micro- and macrophysical properties of the clouds such as ice crystal number and size and cloud top height and cover. Those properties vary significantly depending on the dynamical and thermodynamical context and in turn affect atmospheric dynamics and thermodynamics and consequently weather events and climate. Clouds comprise a significant climate-feedback component. According to the world climate research programme (WCRP) the role of clouds in the climate system is one of the main reasons for the uncertainty in the sensitivity of climate due to increasing greenhouse gas concentrations.

The focus of the cloud research at the institute is ice clouds. Improved understanding of natural ice clouds is an important foundation for studies of the climate impact of air traffic, a core task of DLR. The research on ice clouds is tightly interwoven with the topic areas aerosol-cloud-interaction and water vapor, since ice clouds have a significant impact on the stratospheric water vapor.

Our work comprises

  • the micro- and macrophysical properties of clouds and their variability
  • the role of different microphysical processes
  • the radiative impact
  • life cycles of clouds, e.g. convectively generated clouds (see figure), and their impact on the local water budget
  • changes of clouds in a changing climate

A wide spectrum of methods, ranging from in-situ measurements to active and passive remote sensing methods, and from process and high resolution modelling (LES) to climate modelling, are being pursued within the institute and brought together for cross departmental research within the matrix group.

Thunderstorm over Germany on the 20 th
June 2013 observed with the weather satellite Meteosat-9 (left). Deduced ice water mass per unit area (ice water path) along the transect of the polar orbiting research satellites of A-Train from Meteosat-9, A-Train and two high resolution (625m and 156m) model simulations with the ICON-model (right). (Graphics: ©DLR)