Satellite Limb-Scatter Observations of Stratospheric NO2 and O3 -Retrievals, Validation and Applications
Doktorsavhandling, 2008

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.

satellite

NO2

Odin

limb-scatter

validation

OSIRIS

stratosphere

remote sensing

O3

retrieval

EB-salen, EDIT huset, Hörsalsvägen 11
Opponent: John Burrows, Institute of Environmental Physics, University of Bremen, Germany

Författare

Samuel Brohede

Chalmers, Institutionen för radio- och rymdvetenskap, Global miljömätteknik

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

Canadian Journal of Physics,; Vol. 85(2007)p. 1253-1274

Artikel i vetenskaplig tidskrift

Internal consistency in the Odin stratospheric ozone products

Canadian Journal of Physics,; Vol. 85(2007)p. 1275-1285

Artikel i vetenskaplig tidskrift

Validation of Odin/OSIRIS stratospheric NO2 profiles

Journal of Geophysical Research,; Vol. 112(2007)

Artikel i vetenskaplig tidskrift

Status of the Odin/OSIRIS stratospheric O3 and NO2 data products

Canadian Journal of Physics,; Vol. 85(2007)p. 1177-1194

Artikel i vetenskaplig tidskrift

Ämneskategorier

Fysikalisk kemi

Meteorologi och atmosfärforskning

Geofysik

ISBN

978-91-7385-054-4

Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 2735

EB-salen, EDIT huset, Hörsalsvägen 11

Opponent: John Burrows, Institute of Environmental Physics, University of Bremen, Germany