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Title: GFIT2: an experimental algorithm for vertical profile retrieval from near-IR spectra

Abstract

An algorithm for retrieval of vertical profiles from ground-based spectra in the near IR is described and tested. Known as GFIT2, the algorithm is primarily intended for CO 2, and is used exclusively for CO 2 in this paper. Retrieval of CO 2 vertical profiles from ground-based spectra is theoretically possible, would be very beneficial for carbon cycle studies and the validation of satellite measurements, and has been the focus of much research in recent years. GFIT2 is tested by application both to synthetic spectra and to measurements at two Total Carbon Column Observing Network (TCCON) sites. We demonstrate that there are approximately 3° of freedom for the CO 2 profile, and the algorithm performs as expected on synthetic spectra. We show that the accuracy of retrievals of CO 2 from measurements in the 1.61 μ (6220 cm -1) spectral band is limited by small uncertainties in calculation of the atmospheric spectrum. We investigate several techniques to minimize the effect of these uncertainties in calculation of the spectrum. These techniques are somewhat effective but to date have not been demonstrated to produce CO 2 profile retrievals with sufficient precision for applications to carbon dynamics. As a result, we finish bymore » discussing ongoing research which may allow CO 2 profile retrievals with sufficient accuracy to significantly improve the scientific value of the measurements from that achieved with column retrievals.« less

Authors:
 [1];  [2];  [3];  [3];  [3]
  1. BC Consulting Ltd., Martinborough (New Zealand)
  2. National Institute for Water and Atmospheric Research, Wellington (New Zealand)
  3. California Inst. of Technology (CalTech), Pasadena, CA (United States)
Publication Date:
Research Org.:
BC Consulting Limited, Martinborough (New Zealand)
Sponsoring Org.:
USDOE
OSTI Identifier:
1375413
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Atmospheric Measurement Techniques (Online)
Additional Journal Information:
Journal Name: Atmospheric Measurement Techniques (Online); Journal Volume: 9; Journal Issue: 8; Journal ID: ISSN 1867-8548
Publisher:
European Geosciences Union
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES

Citation Formats

Connor, Brian J., Sherlock, Vanessa, Toon, Geoff, Wunch, Debra, and Wennberg, Paul O. GFIT2: an experimental algorithm for vertical profile retrieval from near-IR spectra. United States: N. p., 2016. Web. doi:10.5194/amt-9-3513-2016.
Connor, Brian J., Sherlock, Vanessa, Toon, Geoff, Wunch, Debra, & Wennberg, Paul O. GFIT2: an experimental algorithm for vertical profile retrieval from near-IR spectra. United States. doi:10.5194/amt-9-3513-2016.
Connor, Brian J., Sherlock, Vanessa, Toon, Geoff, Wunch, Debra, and Wennberg, Paul O. Tue . "GFIT2: an experimental algorithm for vertical profile retrieval from near-IR spectra". United States. doi:10.5194/amt-9-3513-2016. https://www.osti.gov/servlets/purl/1375413.
@article{osti_1375413,
title = {GFIT2: an experimental algorithm for vertical profile retrieval from near-IR spectra},
author = {Connor, Brian J. and Sherlock, Vanessa and Toon, Geoff and Wunch, Debra and Wennberg, Paul O.},
abstractNote = {An algorithm for retrieval of vertical profiles from ground-based spectra in the near IR is described and tested. Known as GFIT2, the algorithm is primarily intended for CO2, and is used exclusively for CO2 in this paper. Retrieval of CO2 vertical profiles from ground-based spectra is theoretically possible, would be very beneficial for carbon cycle studies and the validation of satellite measurements, and has been the focus of much research in recent years. GFIT2 is tested by application both to synthetic spectra and to measurements at two Total Carbon Column Observing Network (TCCON) sites. We demonstrate that there are approximately 3° of freedom for the CO2 profile, and the algorithm performs as expected on synthetic spectra. We show that the accuracy of retrievals of CO2 from measurements in the 1.61μ (6220 cm-1) spectral band is limited by small uncertainties in calculation of the atmospheric spectrum. We investigate several techniques to minimize the effect of these uncertainties in calculation of the spectrum. These techniques are somewhat effective but to date have not been demonstrated to produce CO2 profile retrievals with sufficient precision for applications to carbon dynamics. As a result, we finish by discussing ongoing research which may allow CO2 profile retrievals with sufficient accuracy to significantly improve the scientific value of the measurements from that achieved with column retrievals.},
doi = {10.5194/amt-9-3513-2016},
journal = {Atmospheric Measurement Techniques (Online)},
number = 8,
volume = 9,
place = {United States},
year = {Tue Aug 02 00:00:00 EDT 2016},
month = {Tue Aug 02 00:00:00 EDT 2016}
}

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