Middle Atmosphere Research

Our Atmospheric Physics research aims at a better understanding of the middle atmosphere between 10 and 100 km.  A particular focus is on the processes that control the Earth's mesosphere as a transition region between the lower atmosphere and our near space environment.

Ice Polar Stratopheric Clouds
photo by. P Achtert

Long-term goals of our research program are

  • to establish the distribution and properties of important trace gases, aerosols and clouds in the middle atmosphere,
  • to obtain a better understanding of the microphysical, radiative, and chemical interactions that determine their properties and variability, and
  • to understand underlying transport processes and the dynamical coupling between various parts of the atmosphere.


Hygrosonde rocket launch Experimental efforts are at the core of our research programme. Remote sensing and in situ techniques are applied from satellites, sounding rockets, balloons and the ground. The development of retrieval algorithms complements this work. Laboratory studies aim at the development of improved measuring techniques. Related modeling efforts are essential to couple measurement data to our scientific objectives. Obviously, extensive international co-operation is of central importance for these projects.


Satellite Studies and Data Assimilation

Atmospheric Physics
Atmospheric Physics

The atmospheric mission of the Swedish Odin satellite was planned at MISU since the start of the project in the early 1990s. Odin was launched on February 20, 2001, and has since then provided a wealth of middle atmospheric and astronomical data. Involvement in other middle atmosphere satellites concerns the Atmospheric Chemistry Experiment on the Canadian SCISAT-1 the Michelson Interferometer for Passive Soundings on ENVISAT, the Microwave Limb Sounder on Aura and the phase-A study for the proposed Swedish satellite STEAM.

As for tropospheric studies, MISU contributes to ESA's ADM-Aeolus satellite with the development of new methods for wind data assimilation. Another study concerns the retrieval of tropospheric aerosols.


MATS - the next Swedish research satellite

The mesosphere region of the atmosphere extends from approximately 50 to 100 km above sea level and borders space. Just as the lower atmosphere, this region has been influenced by human activity since the start of the industrial revolution. However, atmospheric models used in this region have limited ability to predict future changes. One of the limiting factors are large uncertainties in the global distribution of atmospheric waves. These waves are density variations in the atmosphere, created for example as winds pass over a mountain top, and are critical for understanding the dynamics of the mesosphere.  They are often called gravity waves since gravity is the restoring force.

MATS (Mesospheric Airglow/Aerosol Tomography and Spectroscopy) is an upcoming Swedish satellite mission designed to investigate atmospheric waves. It will do so by imaging variation in the light emitted by oxygen molecules at 100 km, as well as structures in the highest clouds in our atmosphere, the so-called noctilucent clouds, which form around 80 km. By performing a tomographic analysis of these images, 3D reconstruction of these waves can be done. This will allow the MATS mission to provide the first global map of the properties of atmospheric waves in all spatial dimensions.

The MATS mission is based on the development of the InnoSat spacecraft concept. The InnoSat spacecraft is a small, capable and low-cost platform intended for a range of scientific research missions in Low Earth Orbit. It is designed to fit within a piggyback launch envelope, and has a mass of roughly 50 kg mass and a size of 60×70×85 cm. The satellite is being developed by OHB Sweden, ÅAC Microtec, Department of Meteorology (MISU) at Stockholm University, Department of Earth and Space Sciences at Chalmers, Space and Plasma Physics Group at KTH and Omnisys Instruments. The mission is funded by the Swedish National Space Board (SNSB).

The satellite is scheduled for launch 2019.