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 | Copyright
https://doi.org/10.5194/gmd-2018-198
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

Development and technical paper 23 Oct 2018

Development and technical paper | 23 Oct 2018

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

Improving climate model accuracy by exploring parameter space with an O(105) member ensemble and emulator

Sihan Li1,2, David E. Rupp3, Linnia Hawkins3,6, Philip W. Mote3,6, Doug McNeall4, Sarah N. Sparrow2, David C. H. Wallom2, Richard A. Betts4,5, and Justin J. Wettstein6,7,8 Sihan Li et al.
  • 1Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford, United Kingdom
  • 2Oxford e-Research Centre, University of Oxford, Oxford, United Kingdom
  • 3Oregon Climate Change Research Institute, College of Earth, Ocean, and Atmospheric Science, Oregon State University, Corvallis, Oregon
  • 4Met Office Hadley Centre, FitzRoy Road, Exeter, United Kingdom
  • 5College of Life and Environmental Sciences, University of Exeter, Exeter, UK
  • 6College of Earth, Ocean, and Atmospheric Science, Oregon State University, Corvallis, Oregon
  • 7Geophysical Institute, University of Bergen, Bergen, Norway
  • 8Bjerknes Centre for Climate Change Research, Bergen, Norway

Abstract. Understanding the unfolding challenges of climate change relies on climate models, many of which have large summer warm and dry biases over Northern Hemisphere continental mid-latitudes. This work, using the example of the model used in the updated version of the weather@home distributed climate model framework, shows the potential for improving climate model simulations through a multi-phased parameter refinement approach, particularly over northwestern United States(NWUS). Each phase consists of 1) creating a perturbed physics ensemble with the coupled global – regional atmospheric model, 2) building statistical emulators that estimate climate metrics as functions of parameter values, 3) and using the emulators to further refine the parameter space. The refinement process includes sensitivity analyses to identify the most influential parameters for various model output metrics; results are then used to cull parameters with little influence. Three phases of this iterative process are carried out before the results are considered to be satisfactory; that is, a handful of parameter sets are identified that meet acceptable bias reduction criteria. Results not only indicate that 74% of the NWUS regional warm biases can be reduced by refining global atmospheric parameters that control convection and hydrometeor transport, and land surface parameters that affect plant photosynthesis, transpiration and evaporation, but also suggest that this iterative approach to perturbed physics has an important role to play in the evolution of physical parameterizations.

Sihan Li et al.
Interactive discussion
Status: open (until 18 Dec 2018)
Status: open (until 18 Dec 2018)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement
Sihan Li et al.
Viewed
Total article views: 544 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
467 74 3 544 7 2 3
  • HTML: 467
  • PDF: 74
  • XML: 3
  • Total: 544
  • Supplement: 7
  • BibTeX: 2
  • EndNote: 3
Views and downloads (calculated since 23 Oct 2018)
Cumulative views and downloads (calculated since 23 Oct 2018)
Viewed (geographical distribution)
Total article views: 544 (including HTML, PDF, and XML) Thereof 543 with geography defined and 1 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Cited
Saved
No saved metrics found.
Discussed
Latest update: 13 Nov 2018
Publications Copernicus
Download
Short summary
Understanding the unfolding challenges of climate change relies on climate models, many of which have regional biases larger than the expected climate signal over the next half century. This work shows the potential for improving climate model simulations through a multi-phased parameter refinement approach. Regional warm biases are substantially reduced, suggesting this iterative approach is one path to improving climate models and simulations of present and future climate.
Understanding the unfolding challenges of climate change relies on climate models, many of which...
Citation
Share