Research group Polar Meteorology and Oceanography
The global warming is not uniformly distributed over the Earth. The polar regions are especially sensitive for climate change and the warming in the Arctic is more than twice as fast as for the Earth on average. The effects of this warming are large, with a dramatic loss of sea ice as an example.
The atmosphere in the polar regions is strongly affected by the unique environment, for example, the sun is absent during large parts of the year, the surface is covered by snow or ice, and the air is relatively clean. Weather systems from lower latitudes have a large influence on the polar regions as they bring mild and moist air. Many processes in the atmosphere have unique characteristics in the polar regions and this is the focus of our research.
The polar climate ultimately depends on a balance between the energy transported in from lower latitudes and that lost to space at the top of the atmosphere by radiation. Our research deals with both branches of the balance.
The fast Arctic warming depends on several strong feedbacks, where changing surface reflectivity, as snow and ice melts, and vertical structure of the troposphere are important factors, as are clouds and interactions between ocean, ice and atmosphere. Intrusions of warm and moist air from lower latitudes, often during high-pressure blocks, are also important and here interactions between the troposphere and the upper atmosphere also plays a role.
The lower atmosphere over the polar regions is often cloudy, in particular over the Arctic and the Southern Ocean where low clouds or fog dominate. The ice crystals and supercooled cloud droplets within the clouds are formed on aerosols – microscopic particles – and the natural concentration of these is low in the polar regions. Microorganisms in the surface water could be an important source.
The clouds affect radiation, turbulent mixing and energy exchange at the surface, which governs for example ice formation and melt. The surface cools if the sky is clear, in particular in winter, and strong and long-lived temperature inversions are formed, which prevent mixing of the air close to the surface.
The highest clouds in the world are also located over the poles, noctilucent clouds that form during summer in the middle atmosphere, where the air is the coldest over the summer poles.
Group description
Our research aims at understanding the most important processes for polar climate and its sensitivity, especially for the Arctic, and is focused on clouds and their properties as well as on how particles, clouds, turbulence, waves and energy fluxes interact. The goal is to describe these processes in the computer models we often use to understand the complex climate system. The research is broad, on the ocean and the whole atmosphere –troposphere, stratosphere and mesosphere – and on all scales, from molecules, cloud droplets and turbulence to global dynamics.
We develop and use experimental methods, with observations from platforms such as the Swedish research icebreaker Oden, rockets and the research satellites Odin and MATS. We also develop theory and use and develop different types of machine learning methods and computer models on different scales.
Our research is done in an international setting and we collaborate with many institutes, organisations and centers both within Sweden and internationally. The main collaborators are listed in the righthand panel under "Partners".
Group members
Group managers
Annica Ekman
Professor of Meteorology
Caroline Leck
Professor of Chemical meteorology
Frida Bender
Associate professor
Gunilla Svensson
Professor of Meteorology
Johan Nilsson
Professor of Meteorology
Jörg Gumbel
Professor of Atmospheric physics
Linda Megner
Researcher, docent
Michael Tjernström
Professor Emeritus of Boundary layer meteorology
Rodrigo Caballero Augi
Professor of Dynamic meteorology
Members
Anna Lewinschal
Scientific programmer
Björn Linder
PhD student
Jacek Stegman
Researcher
Jan-Adrian Henriksen Kallmyr
PhD student
Joachim Dillner
Research engineer
John Prytherch
Guest Researcher
Jonas Hedin
Researcher
Jonathan Wiskandt
PhD student
Maura Dewey
PhD student
Michail Karalis
PhD student
Ole Martin Christensen
Researcher Consultant
Sonja Murto
Postdoctor
Tuomas Naakka
Postdoctor
