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Journal of Applied Remote Sensing • Open Access

Impact of atmospheric state uncertainties on retrieved XCO2 columns from laser differential absorption spectroscopy measurements
Author(s): T. Scott Zaccheo; Timothy Pernini; Hilary E. Snell; Edward V. Browell

Paper Abstract

This work assesses the impact of uncertainties in atmospheric state knowledge on retrievals of carbon dioxide column amounts (XCO2) from laser differential absorption spectroscopy (LAS) measurements. LAS estimates of XCO2 columns are normally derived not only from differential absorption observations but also from measured or prior knowledge of atmospheric state that includes temperature, moisture, and pressure along the viewing path. In the case of global space-based monitoring systems, it is often difficult if not impossible to provide collocated in situ measurements of atmospheric state for all observations, so retrievals often rely on collocated remote-sensed data or values derived from numerical weather prediction (NWP) models to describe the atmospheric state. A radiative transfer-based simulation framework, combined with representative global upper-air observations and matched NWP profiles, was used to assess the impact of model differences on estimates of column CO2 and O2 concentrations. These analyses focus on characterizing these errors for LAS measurements of CO2 in the 1.57-μm region and of O2 in the 1.27-μm region. The results provide a set of signal-to-noise metrics that characterize the errors in retrieved values associated with uncertainties in atmospheric state and provide a method for selecting optimal differential absorption line pairs to minimize the impact of these noise terms.

Paper Details

Date Published: 8 August 2014
PDF: 16 pages
J. Appl. Remote Sens. 8(1) 083575 doi: 10.1117/1.JRS.8.083575
Published in: Journal of Applied Remote Sensing Volume 8, Issue 1
Show Author Affiliations
T. Scott Zaccheo, Atmospheric and Environmental Research, Inc. (United States)
Timothy Pernini, Atmospheric and Environmental Research, Inc. (United States)
Hilary E. Snell, Atmospheric and Environmental Research, Inc. (United States)
Edward V. Browell, NASA Langley Research Ctr. (United States)


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