Joint Seminar: Projected changes in low cloud albedo in Southern Ocean extratropical cyclones induced by morphological transitions
The shortwave radiation bias over the Southern Ocean is related to a poor understanding of low clouds in the cold sector of cyclones, where frequent transitions between low cloud mesoscale morphologies occur. Our previous study applied principal component (PC) analysis to cyclone-related cloud controlling factors (CCFs) to explain the frequency of morphologies in extratropical cyclones over the Southern Ocean. The first three PCs are related to cyclone intensity, sea surface temperature, and the development stage of cyclones, respectively. The frequency of occurrence of morphologies within each cyclone can be predicted by insolation and the PCs. Binning the grid cells by solar altitude angles, we are able to reconstruct the average low cloud albedo of each cyclone solely based on the frequency of each low cloud morphology. The identified relationships are then applied to CMIP6 model outputs of CCFs in future cyclones to predict the changes in the frequency of morphologies and the resulting changes in low cloud albedo. The results are expected to help reduce uncertainties in the radiation bias and low cloud feedback over the Southern Ocean.
Datum
07.10.2025
Uhrzeit
15:15 h
Ort
- Bundesstr. 53, room 022/023
- Seminar Room 022/023, Ground Floor, Bundesstrasse 53, 20146 Hamburg, Hamburg