Remote Measurements of Atmospheric Carbon Column Densities: Error Analysis and Early Results
Abstract
A global network for tropospheric carbon column density observations is currently being developed. Fourier Transform Spectrometers (FTS) operating in near-infrared solar absorption will measure column densities of CO2, CH4, and CO simultaneously. Such observations provide atmospheric sampling complementary to in-situ measurements, and will greatly reduce uncertainties in the inference of surface-atmosphere carbon flux. Here we present a preliminary analysis of errors expected in the absorption spectra, and how they affect the column densities. Algorithms using both fixed and variable altitude profile shapes are considered ("profile scaling" and "profile retrieval", respectively). The types of error studied include both fixed and variable forward model errors such as molecular line broadening and the atmospheric temperature profile, as well as noise and smoothing error. We also present preliminary results of CO2, CH4, and CO column measurements made at Lauder, New Zealand, and compare their variability to that predicted by the error analysis.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2004
- Bibcode:
- 2004AGUFM.B23A0921C
- Keywords:
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- 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0315 Biosphere/atmosphere interactions;
- 0365 Troposphere: composition and chemistry;
- 0394 Instruments and techniques;
- 0400 Biogeosciences