Title: Comment on "Radiative forcings for 28 potential Archean greenhouse gases" by Byrne and Goldblatt (2014)

Abstract

In the recent article by Byrne and Goldblatt, "Radiative forcing for 28 potential Archean greenhouse gases", Clim. Past. 10, 1779–1801 (2014), the authors employ the HITRAN2012 spectroscopic database to evaluate the radiative forcing of 28 Archean gases. As part of the evaluation of the status of the spectroscopy of these gases in the selected spectral region (50–1800 cm^-1), the cross sections generated from the HITRAN line-by-line parameters were compared with those of the PNNL database of experimental cross sections recorded at moderate resolution. The authors claimed that for NO₂, HNO₃, H₂CO, H₂O₂, HCOOH, C₂H₄, CH₃OH and CH₃Br there exist large or sometimes severe disagreements between the databases. In this work we show that for only three of these eight gases a modest discrepancy does exist between the two databases and we explain the origin of the differences. For the other five gases, the disagreements are not nearly at the scale suggested by the authors, while we explain some of the differences that do exist. In summary, the agreement between the HITRAN and PNNL databases is very good, although not perfect. Typically differences do not exceed 10 %, provided that HITRAN data exist for the bands/wavelengths of interest. It appears thatmore » a molecule-dependent combination of errors has affected the conclusions of the authors. In at least one case it appears that they did not take the correct file from PNNL (N₂O₄ (dimer)+ NO₂ was used in place of the monomer). Finally, cross sections of HO₂ from HITRAN (which do not have a PNNL counterpart) were not calculated correctly in BG, while in the case of HF misleading discussion was presented there based on the confusion by foreign or noise features in the experimental PNNL spectra.« less

Authors:

Kochanov, R. V. ^[1]; Gordon, I. E.  ^[2];

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Rothman, L. S. ^[2]; Sharpe, S. W. ^[3]; Johnson, T. J. ^[3]; Sams, R. L. ^[3]

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+ Show Author Affiliations

1. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Tomsk State Univ. (Russia)
2. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)
3. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

Publication Date:

Tue Aug 25 00:00:00 EDT 2015

Research Org.:

Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

Sponsoring Org.:

USDOE

OSTI Identifier:

1214395

Grant/Contract Number:  

NNX13AI59G; AC05-76RL01830

Resource Type:

Accepted Manuscript

Journal Name:

Climate of the Past (Online)

Additional Journal Information:

Journal Name: Climate of the Past (Online); Journal Volume: 11; Journal Issue: 8; Journal ID: ISSN 1814-9332

Publisher:

European Geosciences Union

Country of Publication:

United States

Language:

English

Subject:

54 ENVIRONMENTAL SCIENCES