Cloudy skies

The atmosphere is remarkably cloudy. On average, clouds cover more than 50% of the atmosphere. Some latitudes even have a mean cloud cover exceeding 80%.

How do clouds, in particular convective clouds,
impact our weather and climate?

With a group of motivated scientists I try to unravel the role of convective clouds, with a special focus on how they influence the winds that carry them around. Read more about my research and that of my group below, including the CloudBrake project funded by the European Research Commission.


Even small clouds do not simply drift with the wind

The ERC CloudBrake project (2017-2022) strives to understand the impact of momentum transport by (shallow) cumulus convection on large-scale patterns of winds, which is important for numerical weather prediction, climate modeling, and wind energy design. The goal of CloudBrake is to expose relationships between shallow clouds and the vertical structure of wind, and to estimate the amount of cumulus friction that takes place in different large-scale flows, such as in the subtropical trade-winds. The research that we carry out combines high-resolution modeling (Large Eddy Simulation) and global modeling with the analysis of existing and new observations from ground and from space.

Research themes

Trimodal convection

In nature, moist convection prefers three modes: shallow, congestus and deep cumulus. Using a conceptual model, can we understand what processes help set the depth of convection in tropical circulations?

Warm rain over oceans

Warm rain is that produced by clouds with tops below the freezing level. Observations reveal that warm rain is a significant part of rainfall over global oceans, with implications for atmospheric dynamics.

Vertical structure of low cloud

Global models disagree on how low clouds respond to increasing carbon dioxide concentrations, and observations show how this behavior might relate to the vertical structure of low cloud produced by models.