Hosts: Xia Li and Leo Donner

The Arctic region is the most sensitive place on Earth to climate change and has been observed to warm more rapidly than the rest of the globe – a phenomenon known as “Arctic Amplification”. For instance, by 2014, the globe as a whole had warmed on average by ~1K since pre-industrial, while the Arctic region is observed to warm by ~3K and is projected to continue warm by two to four times the levels of global warming in the future. Sea ice, as a critical component of the global climate system, plays a vital role in regulating the energy and mass exchange between the atmosphere and the Arctic Ocean. The seasonal thawing and freezing of sea ice enables the Arctic Ocean to receive solar energy through the exposed open water during summer and then release the heat back to the overlying atmosphere through sea ice during the polar night. While the maximum sea ice loss since the satellite era is in summer, the greatest Arctic warming occurs in winter. In all these ways, sea ice contributes to the amplified Arctic warming not only via declines in the sea ice cover but also thickness, especially in the polar night when the sea ice cover is high and has changed little.

Moreover, sea ice is not uniform; instead, there are a certain amount of areas where sea ice is cracked/advected and thereby water is exposed to the atmosphere, significantly enhancing the air-sea turbulent heat exchange. Taken together, this project aims to understand the role of sea ice, with a particular focus on the ice thickness and openings within the ice (e.g., sea ice leads, polynyas), on Arctic warming. We will leverage the existing modeling data from the GFDL’s coupled global climate model and explore the different components of heat exchange (e.g., turbulent and conductive heat transport) through the sea ice as well as open water within it and try to build a physical understanding of their role by potentially linking to the near-surface air temperature.

By the end of the project, the candidate will gain a comprehensive introduction to the Arctic amplified warming, experience in dealing with big data from the global climate model, and experience in creating new knowledge that is built up upon numerous previous efforts (aka, doing science work). Alternatively, depending on the background and interest of the potential candidate, we can work together to tailor the project and explore related topics of mutual interest.