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Satellite Limb-Scatter Observations of Stratospheric NO2 and O3 -Retrievals, Validation and Applications

Samuel Brohede (Institutionen för radio- och rymdvetenskap, Global miljömätteknik)
Göteborg : Chalmers University of Technology, 2008. ISBN: 978-91-7385-054-4.- 162 s.

Global observations of vertically resolved atmospheric constituents with high temporal and spatial sampling are crucial for various scientific assessments of ozone depletion and climate change. This thesis explains how such data can be retrieved from satellite limb-scatter observations. The main focus is stratospheric NO2 and O3 measured by the the Optical Spectrograph and Infra-Red Imager System (OSIRIS) aboard the Swedish satellite Odin, although the principles can be used for any similar instrument, for other gases and atmospheric regions. The entire process from detector photon counts to a validated operational data product is covered. Transformations of observed radiances to effective column densities for NO2 and Chappuis triplets for O3 in combination with a normalization, significantly reduces the sensitivity to aerosol, clouds, instrument effects and absolute calibration. A maximum a posteriori inversion method produces well behaved data and provides estimates of measurement uncertainty and vertical resolution for individual profiles. Credible data are generally found between 12 and 42 km with a vertical resolution of around 2 km and random uncertainties of about 5\% for O3 and 10\% for NO2. External comparisons reveal good agreement between 25 and 35 km and long-term stability. Sensitivity studies identify four major concerns; stray light contamination, inaccurate pointing, atmospheric inhomogeneities and clouds. Applications of OSIRIS data and the construction of global climatologies of NO2, O3 and NOy are also presented together with model comparisons which indicate inaccurate simulations of heterogeneous nitrogen processes.

Nyckelord: satellite, stratosphere, remote sensing, limb-scatter, Odin, OSIRIS, NO2, O3, retrieval, validation

Denna post skapades 2008-01-21. Senast ändrad 2013-09-25.
CPL Pubid: 67523


Institutioner (Chalmers)

Institutionen för radio- och rymdvetenskap, Global miljömätteknik (2005-2008)


Meteorologi och atmosfärforskning

Chalmers infrastruktur

Relaterade publikationer

Inkluderade delarbeten:

Retrievals of stratospheric O<sub>3</sub> and NO<sub>2</sub> profiles from Odin Optical Spectrograph and InfraRed Imager System (OSIRIS) limb-scattered sunlight measurements

Validation of Odin/OSIRIS stratospheric NO2 profiles

Status of the Odin/OSIRIS stratospheric O<sub>3</sub> and NO<sub>2</sub> data products

A stratospheric NO2 climatology from Odin/OSIRIS limb-scatter measurements

Internal consistency in the Odin stratospheric ozone products


Datum: 2008-02-21
Tid: 13:15
Lokal: EB-salen, EDIT huset, Hörsalsvägen 11
Opponent: John Burrows, Institute of Environmental Physics, University of Bremen, Germany

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Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie 2735