Mesospheric measurements using microwave spectroscopy
Doktorsavhandling, 2015

The mesosphere is an altitude region of the atmosphere, covering altitudes between about 50 km to 100 km. Improved understanding of this area of the atmosphere offers possibilities of increasing the accuracy of weather forecast and climate models. Continuous measurements at these altitudes are difficult as neither balloon nor airplanes can reach such heights. However, by remotely measuring thermal emission emitted in the microwave region, properties such as the atmospheric temperature and the abundance of species such as water vapour and ozone, can be determined from instruments placed on the ground or on satellites. In this thesis microwave spectroscopy is used to measure carbon monoxide above the Onsala Space Observatory located south of Gothenburg, Sweden. The results of the measurements are compared to, and found in good agreement with, co-located data from satellite instruments. A new inversion technique is also demonstrated which integrates the temporal averaging of spectra directly into the retrieval. This shows that ground-based microwave instruments are well suited for mesospheric monitoring, which will become more important in the future as many of the satellite instruments used in the comparison are slated for retirement, with no immediate replacements planned. Microwave spectroscopy can also be used in studies related to polar mesospheric clouds. These are clouds that form in the uppermost part of the summer mesosphere and are extremely sensitive to temperature changes in the background atmosphere. In this thesis tomographic measurements from the sub-millimetre radiometer on-board the Odin satellite are used to retrieve 2-D images of the background temperature and water vapour around these clouds. Combining these results with measurements of ice content and ice particle sizes in the clouds from Odin's other instrument OSIRIS, allows us to investigate the relationship between the horizontal and vertical features in the clouds and their background atmosphere with a hitherto unsurpassed resolution.

water vapour

microwave spectroscopy

polar mesospheric clouds

remote sensing

mesosphere

retrieval

carbon monoxide

temperature

ozone

noctilucent clouds

Kollektorn, MC2 Building , Kemivägen 9, Chalmers University of Technology
Opponent: Priv.-Doz. Dr. Thomas von Clarmann, The Institute of Meteorology and Climate Research - Atmospheric Trace Gases and Remote Sensing, Karlsruhe Institute of Technology, Germany

Författare

Ole Martin Christensen

Chalmers, Rymd- och geovetenskap, Global miljömätteknik och modellering

Tomographic retrieval of water vapour and temperature around polar mesospheric clouds using Odin-SMR

Atmospheric Measurement Techniques,; Vol. 8(2015)p. 1981-1999

Artikel i vetenskaplig tidskrift

Time series inversion of spectra from ground-based radiometers

Atmospheric Measurement Techniques,; Vol. 6(2013)p. 1597-1609

Artikel i vetenskaplig tidskrift

Ämneskategorier

Meteorologi och atmosfärforskning

Fundament

Grundläggande vetenskaper

ISBN

978-91-7597-235-0

Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 3916

Kollektorn, MC2 Building , Kemivägen 9, Chalmers University of Technology

Opponent: Priv.-Doz. Dr. Thomas von Clarmann, The Institute of Meteorology and Climate Research - Atmospheric Trace Gases and Remote Sensing, Karlsruhe Institute of Technology, Germany