A 3D model for O2 airglow perturbations induced by gravity waves in the upper mesosphere

​Subtitle: A forward model for the new Swedish satellite MATS
Anqi Li is a master thesis student at the Department of Earth and Space Sciences, Chalmers and Department of Meteorology, Stockholm University


Abstract:

To investigate the influence of atmospheric waves in the mesosphere, a new Swedish
satellite MATS (Mesospheric Airglow/Aerosol Tomography and Spectroscopy) will
be launched in 2019. It will observe infrared emissions at 762 nm from the O2(b1Σ+g )
airglow in the region of 70 − 110 km altitude. As a part of the design work for the
MATS project, an accurate forward model is needed to estimate what MATS is expected
to measure. The results from this model will be used to evaluate the retrieval
methods for processing the measurements from MATS.
In this thesis project, a gravity wave model and a photochemistry model were coupled
to simulate both the day- and nightglow emission fields in three spatial dimensions
and time. Simulated satellite images were generated taking into consideration
the sphericity of the Earth and the limb-viewing geometry of MATS. Simulation
parameters were set according to the preliminary design of the instrument, such as
the satellite orbit, image resolution and spectral selections. These satellite images
were the first simulated airglow limb images made for the MATS project.
By analysing the output data, the relations between wave parameters and airglow
perturbations were investigated. It was shown that wave patterns can be easily
observed between 88 − 105 km due to the relatively large perturbation in airglow
emissions. The O2 airglow emission field was found to be highly sensitive to atomic
oxygen concentration field as an input. Furthermore, as expected, wave patterns
projected on simulated satellite images largely depend on the horizontal orientation
of the wave propagation. This implies that a tomographic reconstruction is needed
when the angle between the wave front and the limb-viewing direction is large.
Finally, limitations of the model were discussed.
Keywords: MATS, internal gravity wave, mesosphere, O2 airglow.
Supervisor: Ole Martin Christensen, Department of Meteorology, Stockholm University
Examiner: Donal Murtagh, Department of Earth and Space Sciences, Chalmers University of Technology
Opponent: Lorand Gergely
Category Student project presentation
Location: Sektionsgemensamt sammanträdesrum (EDIT-room 3364)
Starts: 04 April, 2017, 14:00
Ends: 04 April, 2017, 15:00

Published: Tue 14 Mar 2017.