Journal cover Journal topic
Geoscientific Model Development An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 4.252 IF 4.252
  • IF 5-year value: 4.890 IF 5-year 4.890
  • CiteScore value: 4.49 CiteScore 4.49
  • SNIP value: 1.539 SNIP 1.539
  • SJR value: 2.404 SJR 2.404
  • IPP value: 4.28 IPP 4.28
  • h5-index value: 40 h5-index 40
  • Scimago H index value: 51 Scimago H index 51
Discussion papers
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

Model experiment description paper 18 Sep 2018

Model experiment description paper | 18 Sep 2018

Review status
This discussion paper is a preprint. It is a manuscript under review for the journal Geoscientific Model Development (GMD).

A benchmark for testing the accuracy and computational cost of shortwave top-of-atmosphere reflectance calculations in clear-sky aerosol-laden atmospheres

Jeronimo Escribano1,a, Alessio Bozzo2, Philippe Dubuisson3, Johannes Flemming2, Robin J. Hogan2, Laurent C.-Labonnote3, and Olivier Boucher1 Jeronimo Escribano et al.
  • 1Institut Pierre-Simon Laplace, CNRS/Sorbonne Université, Paris, France
  • 2European Centre for Medium Range Weather Forecasts, Reading, United Kingdom
  • 3Laboratoire d'Optique Atmosphérique, Université de Lille/CNRS, Villeneuve d'Ascq, France
  • anow at: Barcelona Supercomputing Center (BSC), Barcelona, Spain

Abstract. Accurate calculations of shortwave reflectances in clear-sky aerosol-laden atmospheres are necessary for various applications in atmospheric sciences. However computational cost becomes increasingly important for some applications such as data assimilation of top-of-atmosphere reflectances in models of atmospheric composition. This study aims to provide a benchmark that can help in assessing these two requirements in combination. We describe a protocol and input data for 44,080 cases involving various solar and viewing geometries, four different surfaces (one oceanic bidirectional reflectance function and three albedo values for a Lambertian surface), eight aerosol optical depths, five wavelengths, and four aerosol types. We first consider two models relying on the discrete ordinate method: VLIDORT (in vector and scalar configurations) and DISORT (scalar configuration only). We use VLIDORT in its vector configuration as a reference model and quantify the loss of accuracy due to (i) neglecting the effect of polarisation in the DISORT and VLIDORT (scalar) models and (ii) decreasing the number of streams in DISORT. We further test two other models: the 6SV2 model relying on the successive orders of scattering method and FLOTSAM, a new model under development by two of the authors. Typical mean fractional errors of 2.8 and 2.4% for 6SV2 and FLOTSAM are found, respectively. Computational cost depends on the input parameters but also on the code implementation and application as some models solve the radiative transfer equations for a range of geometries while others do not. All necessary input and output data are provided as Supplementary Material as a potential resource for interested developers and users of radiative transfer models.

Jeronimo Escribano et al.
Interactive discussion
Status: open (until 02 Jan 2019)
Status: open (until 02 Jan 2019)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement
Jeronimo Escribano et al.
Jeronimo Escribano et al.
Total article views: 388 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
306 76 6 388 13 8 10
  • HTML: 306
  • PDF: 76
  • XML: 6
  • Total: 388
  • Supplement: 13
  • BibTeX: 8
  • EndNote: 10
Views and downloads (calculated since 18 Sep 2018)
Cumulative views and downloads (calculated since 18 Sep 2018)
Viewed (geographical distribution)  
Total article views: 386 (including HTML, PDF, and XML) Thereof 386 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
No saved metrics found.
No discussed metrics found.
Latest update: 10 Dec 2018
Publications Copernicus
Short summary
Accurate shortwave radiance computations is becoming increasingly important for some applications in atmospheric composition. In this work we propose a benchmark protocol and dataset to asses the accuracy and computing runtime of radiance calculations of radiative transfer models. It is applied to four models, showing the potential of this benchmark to evaluate the model performance under a variety of atmospheric conditions, viewing geometries and aerosol loading and optical properties.
Accurate shortwave radiance computations is becoming increasingly important for some...