Case study

A Clear View on Cloud Formation

Global warming caused by greenhouse gas emissions is bringing about all kinds of changes. But one of the most important processes, cloud formation, usually remains underexposed in the process. The research group of Prof Harm Jonker, Atmospheric Physics (TU Delft) aims to change this.

03 November 2023

In short

Who: Harm Jonker
Position: Professor of Atmospheric Physics
Organisation: TU Delft
Service: Visualisation and the national supercomputer
Challenge: How can I accurately model and visualise the influence of climate change on cloud formation?
Solution: The national supercomputer and remote visualisation are used for detailed calculations and efficient visualisation of cloud formation processes.

Cloud formation research

With global warming, all kinds of processes change; for instance, more water vapour enters the atmosphere. "Clouds are also affected, but we don't know exactly what the effects look like," says Jonker. "We do know that clouds determine the amount of radiation that reaches Earth and the radiation that can leave the atmosphere again. It could be that in a warmer climate there will be more low clouds, which have the property of reflecting sunlight well. That would mitigate the effect of warming. But the opposite scenario, fewer low clouds and thus amplification of warming, is also possible. We don't really know how that works yet."

"Such a model calculates with grid cells of about 50 km. We work on a smaller scale, looking at an area of 50 km with grid cells of 50 metres, for example"

Rising seawater temperature

A climate model cannot take cloud type into account, Jonker argues: "Such a model calculates with grid cells of about 50 km. We work on a smaller scale, looking at an area of 50 km with grid cells of 50 metres, for example. We calculate in three dimensions and also in time, so that requires a lot of computing power, but it allows us to accurately follow the process of cloud formation. For instance, we are investigating the effect on cloud formation if you increase the seawater temperature by one degree. One of the key factors we are looking at is whether the reflection of cloud cover increases or decreases in such a case."

Visualisation boosts communication, insight and inspiration

Visualisation is very important for Jonker's research group: "Firstly, we can use the images and animations very well to communicate the results of our research. Secondly, in the visualisation we can immediately see if we have done something wrong. If we have not set an edge condition correctly or if our numerical scheme is not quite right, it is immediately visible. In this sense, a visualisation is relentless. And thirdly, we also use visualisation as a research tool. It inspires us when formulating hypotheses."

"We do our calculations on the national supercomputer, because it often involves a lot of data"

Remote visualisation is much more efficient

Jonker and his colleagues use SURF's Visualisation Service. "That works very well for us," says Jonker. "We do our calculations on the national supercomputer, because this often involves a lot of data. It would take a lot of time to transfer that data to our institute; moreover, powerful systems are needed to build the visualisations. Remote visualisation via SURF is much more efficient; we leave the data wherever the visualisation is made. Only the image is passed on to us."

The only helpdesk that works

Jonker has been working with SURF for almost 20 years: "I still love working with people who are always willing to help solve problems. Moreover, they are very professional. I sometimes say: it's the only helpdesk in the Netherlands that works and where you don't have to wait."