Sea ice, melt ponds and Arctic clouds.                                                                           Photo: Michael Tjernström

What are the main forces behind the rapid loss of summer sea ice in the Arctic? Are the main processes local, such as cloud formation or heat transfer between the atmosphere and the ice, or is warm and moist air imported from the south more important? What will in the future happen if society raises to the challenge and reduces emissions of greenhouse gases according to the Paris agreement? To answer questions like this requires both climate models and observations. But the models perform poorly in the Arctic and observations are sparse.

In the Arctic Climate Across Scales project, funded by the Knut and Alice Wallenberg foundation, we take an integrated perspective across spatial and temporal scales to answer such questions. One building block is improving our capacity to take detailed observations of important processes. The first steps to build an observatory the Swedish icebreaker Oden are taken this summer during the Arctic Ocean 2018 expedition.

We want to develop an autonomous observatory that allows characterization of the atmosphere vertically from the surface through the atmosphere using a suite of remote-sensing and in-situ instruments. During this first attempt focus will be on the surface exchange of heat, gases and momentum, the atmosphere’s vertical structure and clouds and general meteorology. We also collaborate with the Year of Polar Prediction (YOPP), where we will be providing observations to improve operational weather forecasts and to help improve future computer models for weather forecasts.

ACAS expedition participants from MISU

Michael Tjernström

John Prytherch