Modeling polar processes in the global climate system

An innovative new project named CRiceS – short for Climate relevant interactions and feedback: the key role of sea ice and snow in the polar and global climate system – will enhance our understanding of the ocean-ice-snow-atmosphere system by delivering improved models capable of describing polar and global climates.

The Arctic and Antarctic regions are experiencing rapid and unprecedented changes as a result of polar and global climate change, which is clearly caused by human activity. Under current projections, sea ice in both the Arctic and Antarctic is expected to decrease substantially in the 21st century, affecting people not just in the Arctic but around the world.

The CRiceS project brings together 21 international research teams at the forefront of polar and global climate research in Europe, Canada, South Africa, India and Russia. It aims to enhance the modeling of the impacts that these regions have on the global climate.

With this new project, an exceptionally broad team of researchers – including experts from climate physics, chemistry, and biology – will study the role of polar processes within the climate system. “We believe that our integrated approach, with experts in both modeling and observations, will help us understand not only polar processes, but also how polar systems are linked to the global climate and society,” says Risto Makkonen, the project coordinator and a research professor at the FMI. Julia Schmale, a tenure-track assistant professor at EPFL and head of the Extreme Environments Research Laboratory at EPFL Valais Wallis, will be responsible for implementing the mechanistic understanding gained from in situ observations in order to enhance the researchers’ models (see interview below).

Improving model predictions

The CRiceS project will focus on improving the ability of models to predict the role of polar processes in both the climate system – which consists of oceans, ice and snow cover – and the atmosphere. This is crucial to understanding the role of polar processes, such as feedback loops, in present and future polar and global climates. “Models are our main tool for understanding and predicting climate change,” says Jennie Thomas, the project’s scientific coordinator and a senior research scientist at CNRS. “CRiceS uses a unique multidisciplinary approach to deliver improved descriptions of polar processes and how they function within the Earth system.”

CRiceS will enhance climate models in terms of how polar processes are embedded in the model codes. “After all, global climate models are the key tool for predicting future changes in polar and global climate systems,” says Risto Makkonen. “Improved models should be capable of simulating detailed processes and especially the interactions and coupling of polar systems, such as oceans, sea ice and the atmosphere.”

Research in support of a resilient future and climate action

The project will receive €8 million in EU funding and will run from 2021 to 2025. The EU’s H2020 research program funds projects that support the transformation to a low-carbon, resilient future and the climate action that supports the Paris climate agreement.

The EU plays an extensive role in polar research by coordinating joint Arctic and Antarctic collaboration initiatives. It funds around €200 million in polar research projects under Horizon 2020.

Interview with Julia Schmale, atenure-track assistant professor at EPFL and head of the Extreme Environments Research Laboratory (EERL) at EPFL Valais Wallis

How will your lab contribute to the CRiceS research project?

EERL is one of the few members of the CRiceS consortium that can provide unique in situ datasets from the Arctic and Antarctic Oceans. Our data can be used to obtain a mechanistic understanding of, for example, the conditions under which blowing snow helps build up aerosols – which in turn can influence cloud formation – or to estimate how much iodic acid will be released when sea water freezes [see an earlier article on EERL’s work in this area]. One of our EERL researchers will be dedicated to CRiceS and funded by it. This person will work closely with the CRiceS model developers to translate our mechanistic understanding into the model code. In addition, CRiceS fits in well with several of our other ongoing projects, and a small group of our scientists will contribute to and learn from the consortium’s work. For example, we recently began running a global chemical-transport models, which can now be tagged onto CRiceS with a direct impact.

How do you expect the findings to be useful?

Today’s models struggle to reproduce certain climate-relevant processes that are linked to atmospheric compositions in polar regions because scientists still don’t have accurate mathematical descriptions of these processes. CRiceS aims to overcome this by having the observational and modeling communities work closely together. Concretely, for EERL this means that our data and derived process understanding can have important leverage to improve the models’ performance, which in turn allows for better climate change simulations of polar regions. Those are critical because changes in both the Arctic and Antarctic have global repercussions – think for example of the rise in sea levels.

What are the main challenges of working in extreme areas such as the Arctic and the Antarctic and with so many different researchers?

In CRiceS we will not do field experiments, but rather harness rich datasets that were already obtained. In my experience, collaborating in such large consortia is a very rewarding process because we can combine a wide range of expertise and knowledge to create added value compared to smaller collaborative groups. Quite often, in addition to working on the main project objectives, new research ideas emerge and can lead to new joint projects. This was for example the case in a previous European project that I was involved in, where part of our team joined forces for the Antarctic Circumnavigation Expedition.

When it comes to field work, there are of course many challenges. Most of them are difficult to plan for because they emerge from environmental factors such as moving sea ice, storms and extremely cold temperatures. To still acquire valuable datasets, such as those that we will use in CRiceS, it is important to be patient and persistent. If something doesn’t work the first time, it will in the future; if something breaks, it can be fixed. Here, collaboration with other expedition participants is important, and it is common practice to help each other. This builds not only a professional network but also friendships, an aspect that I particularly value in expedition-based field research.