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Tomographic reconstruction of atmospheric volumes from infrared limb-imager measurements

Abstract

State-of-the art nadir and limb-sounders, but also in situ measurements, do not offer the capability to highly resolve the atmosphere in all three dimensions. This leaves an observational gap with respect to small-scale structures that arise frequently in the atmosphere and that still lack a quantitative understanding. For instance, filaments and tropopause folds in the upper troposphere and lower stratosphere (UTLS) are crucial for its composition and variability. One way to achieve a highly resolved three-dimensional (3-D) picture of the atmosphere is the tomographic evaluation of limb-imager measurements. This thesis presents a methodology for the tomographic reconstruction of atmospheric constituents. To be able to deal with the large increase of observations and unknowns compared to conventional retrievals, great care is taken to reduce memory consumption and processing time. This method is used to evaluate the performance of two upcoming infrared limb-imager instruments and to prepare their missions. The first examined instrument is the infrared limb-imager on board of PREMIER (Process Exploration through Measurements of Infrared and millimetrewave Emitted Radiation), one of three remaining candidates for ESA's 7th Earth Explorer mission. Scientific goals of PREMIER are, among others, the examination of gravity waves and the quantification of processes controlling atmospheric composition  More>>
Authors:
Publication Date:
Aug 12, 2011
Product Type:
Thesis/Dissertation
Report Number:
ETDE-DE-2490
Resource Relation:
Other Information: TH: Diss.; Also available from: http://www.fz-juelich.de/zb/juwel; Related Information: Schriften des Forschungszentrums Juelich. Reihe Energie und Umwelt/Energy and Environment v. 106
Subject:
58 GEOSCIENCES; ATMOSPHERES; CHEMICAL COMPOSITION; EVALUATION; GRAVITY WAVES; INFRARED RADIATION; LIMBS; SIMULATION; TOMOGRAPHY
OSTI ID:
21462755
Research Organizations:
Forschungszentrum Juelich (Germany). Institut fuer Energie- und Klimaforschung (IEK). Stratosphere (IEK-7); Wuppertal Univ. (Germany)
Country of Origin:
Germany
Language:
English
Other Identifying Numbers:
Other: ISBN 978-3-89336-708-5; ISSN 1866-1793; TRN: DE11G8548
Availability:
Commercial reproduction prohibited; OSTI as DE21462755
Submitting Site:
DE
Size:
185 pages
Announcement Date:
Aug 13, 2011

Citation Formats

Ungermann, Joern. Tomographic reconstruction of atmospheric volumes from infrared limb-imager measurements. Germany: N. p., 2011. Web.
Ungermann, Joern. Tomographic reconstruction of atmospheric volumes from infrared limb-imager measurements. Germany.
Ungermann, Joern. 2011. "Tomographic reconstruction of atmospheric volumes from infrared limb-imager measurements." Germany.
@misc{etde_21462755,
title = {Tomographic reconstruction of atmospheric volumes from infrared limb-imager measurements}
author = {Ungermann, Joern}
abstractNote = {State-of-the art nadir and limb-sounders, but also in situ measurements, do not offer the capability to highly resolve the atmosphere in all three dimensions. This leaves an observational gap with respect to small-scale structures that arise frequently in the atmosphere and that still lack a quantitative understanding. For instance, filaments and tropopause folds in the upper troposphere and lower stratosphere (UTLS) are crucial for its composition and variability. One way to achieve a highly resolved three-dimensional (3-D) picture of the atmosphere is the tomographic evaluation of limb-imager measurements. This thesis presents a methodology for the tomographic reconstruction of atmospheric constituents. To be able to deal with the large increase of observations and unknowns compared to conventional retrievals, great care is taken to reduce memory consumption and processing time. This method is used to evaluate the performance of two upcoming infrared limb-imager instruments and to prepare their missions. The first examined instrument is the infrared limb-imager on board of PREMIER (Process Exploration through Measurements of Infrared and millimetrewave Emitted Radiation), one of three remaining candidates for ESA's 7th Earth Explorer mission. Scientific goals of PREMIER are, among others, the examination of gravity waves and the quantification of processes controlling atmospheric composition in the UTLS, a region of particular importance for climate change. Simulations based on the performance requirements of this instrument deliver a vertical resolution that is slightly better than its vertical field-of-view (about 0.75 km) and a horizontal resolution of {approx}25km x 70 km. Non-linear end-to-end simulations for various gravity wave patterns demonstrate that the high 3-D resolution of PREMIER considerably extends the range of detectable gravity waves in terms of horizontal and vertical wavelength compared to previous observations. The second examined instrument is GLORIA (Gimballed Limb Observer for Radiance Imaging of the Atmosphere). This new remote sensing instrument combines a two-dimensional Fourier transform infrared spectrometer with a highly flexible gimbal mount. It is jointly developed by the Research Centre Juelich and the Karlsruhe Institute for Technology for deployment on the German research aircraft HALO (High Altitude and LOng range research aircraft) and the high-flying Russian aircraft Geophysica. GLORIA can be panned horizontally from 45 to 135 and thereby allows for tomographic measurements of mesoscale events for a wide variety of atmospheric constituents. Ozone is used as a test species for optimising the flight path and measurement mode of the instrument for tomographic retrievals. For the first time, it is demonstrated that 3-D tomographic retrievals are possible using such an instrument with an unprecedented 3-D resolution of 200m in the vertical direction and 20 to 30km in the horizontal direction for special flight paths. The long duration of tomographic measurements necessitates the consideration of atmospheric advection. Its effect on tomographic retrievals is therefore quantified and partially compensated by a dedicated method. (orig.)}
place = {Germany}
year = {2011}
month = {Aug}
}