Observations and model calculations at the Leipzig Institute of Meteorology (LIM), University of Leipzig
The Arctic has warmed two to three times more than the rest of the Earth over the last two decades. At the same time, sea ice coverage of the Arctic Ocean has decreased over the last 50 years; especially in late summer, sea ice coverage decreased by more than half. Obviously, the currently observed global climate changes are significantly amplified by specific processes in the Arctic climate system. This phenomenon is commonly referred to as “Arctic amplification”. The specific properties and effects of clouds in the Arctic contribute to Arctic amplification. Arctic clouds are often very long-lived, of mixed-phase character (simultaneous occurrence of liquid super-cooled droplets and ice particles in the clouds), and they can have both warming and cooling effects on the near-ground air layer. The surface (bright, highly reflective sea ice or dark, absorbing ocean) plays an important role. During the polar night in winter, Arctic clouds contribute to warming, whereas in summer they tend to have a cooling effect. To elucidate these and many other important processes contributing to the current enhanced changes in Arctic climate, several groups at LIM are conducting observations using both ground-based and airborne and satellite remote sensing techniques. These are closely coordinated with model studies on a variety of local and temporal scales.
Research questions
- How does the effect of Arctic mixed-phase clouds on the ground-level energy budget depend on macrophysical and microphysical cloud properties and on the surface albedo?
- What causes the longevity of Arctic clouds?
- What is the impact of Arctic ice clouds on ground-level air temperature?
- Can the ice content in Arctic clouds be determined by remote sensing measurements from the ground, aircraft, and satellites?
- How strong is the cloud effect in terms of Arctic enhancement compared to other causes of this phenomenon?
Methods
- Ground-based remote sensing methods
- Aircraft and satellite measurements
- Numerical modeling
Responsible persons
Prof. Dr. Manfred Wendisch, Institute of Meteorology, University of Leipzig
Prof. Dr. Heike Kalesse-Los, Institute of Meteorology, University of Leipzig
Prof. Dr. Johannes Quaas, Institute of Meteorology, University of Leipzig