What's the connection between volcanic emissions and cirrus clouds?

My project aims to better understand the formation of high altitude ice clouds (cirrus clouds) and how volcanic aerosol particles affect those clouds.

Clouds reflect solar radiation back to space and trap infrared radiation that is emitted by the Earth in the atmosphere. By doing this, they significantly influence the energy budget of the Earth. For cirrus clouds, the trapping of infrared radiation dominates which results in a warming effect to Earth's climate.

Cirrus clouds remain a cause of uncertainty in global climate models, because they have a high variability in time and space and due to their complex interplay with meteorological factors like temperature, updraft velocities and aerosol environment. Since climate models are a primary tool to study the effect of global warming on Earth systems, it is crucial to increase our knowledge of cirrus cloud formation, and reduce uncertainties in the climate models. Additionally, the gained knowledge is helpful in assessing climate intervention methods. These methods aim to counteract global warming by artificially altering clouds by inducing aerosols into the atmosphere. 

In the first part of my project, I combine 3D satellite observations of cirrus clouds with reanalysis data of meteorological factors and aerosol concentrations into a unified data set. By applying deep learning and explainable artificial intelligence methods to the data set, I can quantify how individual factors influence cirrus clouds and how this differs by region and in changing circumstances.

In the second part, I analyze the impact of volcanic aerosols on cirrus clouds using supervised and unsupervised machine learning techniques that are able to capture the complex dependencies in the data. This is of particular scientific interest since volcanic eruptions provide the unique opportunity to study the effect of a significant amount of externally induced sulfate aerosols on cirrus clouds in real-​world data.