Journal cover Journal topic
Nonlinear Processes in Geophysics An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 1.129 IF 1.129
  • IF 5-year value: 1.519 IF 5-year 1.519
  • CiteScore value: 1.54 CiteScore 1.54
  • SNIP value: 0.798 SNIP 0.798
  • SJR value: 0.610 SJR 0.610
  • IPP value: 1.41 IPP 1.41
  • h5-index value: 21 h5-index 21
  • Scimago H index value: 48 Scimago H index 48
Discussion papers
https://doi.org/10.5194/npg-2018-21
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/npg-2018-21
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

Research article 27 Mar 2018

Research article | 27 Mar 2018

Review status
This discussion paper is a preprint. A revision of the manuscript for further review has not been submitted.

Sensitivity of forecast skill to the parameterisation of moist convection in a limited-area ensemble forecast system

Matteo Vasconi1,2, Andrea Montani2, and Tiziana Paccagnella2 Matteo Vasconi et al.
  • 1Department of Physics and Astronomy, University of Bologna, Italy
  • 2Arpae-SIMC, HydroMeteoClimate Service of the Emilia-Romagna Region, Bologna, Italy

Abstract. The parameterisation of convection in limited-area models is an important source of uncertainty as regards the spatio-temporal forecast of precipitation. As for the limited-area model COSMO, hitherto, only the Tiedtke convection scheme was available for the operational runs of the model in convection-parameterised mode. In addition to this the Bechtold scheme, implemented in ECMWF global model, has recently been adapted for COSMO applications. The development and implementation of ensemble systems in which different convection schemes are used, provides an opportunity to upgrade state-of-the-art probabilistic systems at the convection-parameterised scale. The sensitivity of the COSMO model forecast skill to the use of either the Tietdke or the Bechtold schemes is assessed by performing different sets of experiments.

The performance of COSMO model run with the different schemes is investigated in ensemble mode with particular attention to the types of forecast errors (e.g. location, timing, intensity) provided by the different convection schemes in terms of total precipitation.

A 10-member ensemble has been run for approximately 2 months with the Bechtold scheme, using the same initial and boundary conditions as members 1–10 of the operational COSMO-LEPS ensemble system (which has 20 members, all run with the Tiedtke scheme). The performance of these members is assessed and compared to that of the system made of members 1–10 of COSMO-LEPS in terms of total precipitation prediction.

Finally, the performance of an experimental 20-member ensemble system (which has 10 members run with the Bechtold plus 10 members run with the Tiedtke scheme) is compared to that of operational COSMO-LEPS over the 2-month period. The new system turned out to have higher skill in terms of precipitation forecast with respect to COSMO-LEPS over the period. In this approach the use of the Bechtold scheme is proposed as a perturbation for the COSMO-LEPS ensemble, relatively to how uncertainties in the model representation of the cumulus convection can be described and quantified.

Matteo Vasconi et al.
Interactive discussion
Status: closed (peer review stopped)
Status: closed (peer review stopped)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
Interactive discussion
Status: closed (peer review stopped)
Status: closed (peer review stopped)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
Matteo Vasconi et al.
Matteo Vasconi et al.
Viewed  
Total article views: 305 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
238 57 10 305 12 15
  • HTML: 238
  • PDF: 57
  • XML: 10
  • Total: 305
  • BibTeX: 12
  • EndNote: 15
Views and downloads (calculated since 27 Mar 2018)
Cumulative views and downloads (calculated since 27 Mar 2018)
Viewed (geographical distribution)  
Total article views: 303 (including HTML, PDF, and XML) Thereof 300 with geography defined and 3 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Cited  
Saved  
No saved metrics found.
Discussed  
No discussed metrics found.
Latest update: 13 Dec 2018
Publications Copernicus
Special issue
Download
Citation
Share