Remember Me
Or use your Academic/Social account:


You have just completed your registration at OpenAire.

Before you can login to the site, you will need to activate your account. An e-mail will be sent to you with the proper instructions.


Please note that this site is currently undergoing Beta testing.
Any new content you create is not guaranteed to be present to the final version of the site upon release.

Thank you for your patience,
OpenAire Dev Team.

Close This Message


Verify Password:
Verify E-mail:
*All Fields Are Required.
Please Verify You Are Human:

OpenAIRE is about to release its new face with lots of new content and services.
During September, you may notice downtime in services, while some functionalities (e.g. user registration, login, validation, claiming) will be temporarily disabled.
We apologize for the inconvenience, please stay tuned!
For further information please contact helpdesk[at]openaire.eu

fbtwitterlinkedinvimeoflicker grey 14rssslideshare1
Bengtsson, L.; Hodges, K. I.; Hagemann, S. (2004)
Publisher: Co-Action Publishing
Journal: Tellus A
Languages: English
Types: Article
The impact of selected observing systems on the European Centre for Medium-Range Weather Forecasts (ECMWF) 40-yr reanalysis (ERA40) is explored by mimicking observational networks of the past. This is accomplished by systematically removing observations from the present observational data base used by ERA40. The observing systems considered are a surface-based system typical of the period prior to 1945/50, obtained by only retaining the surface observations, a terrestrial-based system typical of the period 1950–1979, obtained by removing all space-based observations, and finally a space-based system, obtained by removing all terrestrial observations except those for surface pressure. Experiments using these different observing systems have been limited to seasonal periods selected from the last 10 yr of ERA40. The results show that the surface-based system has severe limitations in reconstructing the atmospheric state of the upper troposphere and stratosphere. The terrestrial system has major limitations in generating the circulation of the Southern Hemisphere with considerable errors in the position and intensity of individual weather systems. The space-based system is able to analyse the larger-scale aspects of the global atmosphere almost as well as the present observing system but performs less well in analysing the smaller-scale aspects as represented by the vorticity field. Here, terrestrial data such as radiosondes and aircraft observations are of paramount importance. The terrestrial system in the form of a limited number of radiosondes in the tropics is also required to analyse the quasi-biennial oscillation phenomenon in a proper way. The results also show the dominance of the satellite observing system in the Southern Hemisphere. These results all indicate that care is required in using current reanalyses in climate studies due to the large inhomogeneity of the available observations, in particular in time.
  • The results below are discovered through our pilot algorithms. Let us know how we are doing!

    • Bengtsson, L. 1999. From short range barotropic modelling to extendedrange global weather prediction. Tellus 51A, 13-32.
    • Bengtsson, L. and Shukla, J. 1988. Integration of space and in situ observations to study climate change. Bull. Am. Meteorol. Soc. 69, 1130- 1143.
    • Bengtsson, L., Hodges, K. I. and Hagemann, S. 2004a. Sensitivity of large scale atmospheric analyses to humidity observations and its impact on the global water cycle and tropical and extratropical weather systems. Tellus 56A, 202-217.
    • Bengtsson, L., Hagemann, S. and Hodges, K. I. 2004b. Can climate trends be computed from reanalysis data? JGR. vol. 109, D11111, doi:10.1029/2004JD004536, 2004.
    • Gibson, J., Ka´llberg, P., Uppala, S., Nomura, A., Hernandez, A. and Serrano, E. 1997. ERA description. ECMWF Reanalysis Final Report Series, 1, ECMWF, Shinfield Park, Reading, UK, 71 pp.
    • Hodges, K. I., Hoskins, B. J., Boyle, J. and Thorncroft, C. 2003. A comparison of recent re-analysis data sets using objective feature tracking: storm tracks and tropical easterly waves. Mon. Wea. Rev. 131, 2012- 2037.
    • Hodges, K. I., Hoskins, B. J., Boyle, J. and Thorncroft, C. 2004. Corrigendum to “A comparison of recent re-analysis data sets using objective feature tracking: storm tracks and tropical easterly waves”. Mon. Wea. Rev. 132, 1325-1327.
    • Hoskins, B. J. and Hodges, K. I. 2002. New perspectives on the northern hemisphere winter storm tracks. J. Atmos. Sci. 59, 1041- 1061.
    • Kalnay, E., Kanamitsu, M., Kistler, R., Collins, W., Deaven, D. et al. 1996. The NCEP/NCAR 40-year reanalysis project. Bull. Am. Meteorol. Soc. 77, 437-471.
    • Kanamitsu, M., Ebisuzaki, W., Woolen, J., Potter, J. and Fiorino, M. 1999. An Overview of Re-Analysis 2. In: Proc. 2nd Int. Conf. on Reanalysis, Reading, UK, WCRP.
    • Lott, F. and Miller, M. J. 1997. A new subgrid-scale ororgraphic drag parameterization: its formulation and testing. J. Atmos. Sci. 31, 118- 133.
    • Mlawer, E. J., Taubman, S. J., Brown, P. D., Iacono, M. J. and Clough, S. A. 1997. Radiative transfer for inhomogeneous atmospheres: RRTM a validated correlated-k model for the longwave. J. Geophys. Res. 102D, 16 663-16 682.
    • Schubert, S. D., Rood, R. B. and Pfaendtner, J. 1993. An assimilated dataset for earth science applications. Bull. Am. Meteorol. Soc. 74, 2331-2342.
    • Simmons, A. J. and Gibson, J. K. 2000. The ERA-40 Project Plan, ERA40 Project Report Series No. 1 ECMWF. Shinfield Park, Reading, UK, 63 pp.
    • Simmons, A. J. and Hollingsworth, A. 2002. Some aspects of the improvement in skill of numerical weather prediction. Q. J. R. Meteorol. Soc. 128, 647-677.
    • Tiedtke, M. 1989. A comprehensive mass flux scheme for cumulas parametrization in large-scale models. Mon. Wea. Rev. 117, 1779- 1800.
    • Whitaker, J. S., Compo, G. P., Wei, X. and Hamill, T. M. 2004. Reanalysis without radiosondes using ensemble data assimilation. Mon. Wea. Rev. 132, 1190-1200.
  • No related research data.
  • No similar publications.

Share - Bookmark

Cite this article

Collected from

Cookies make it easier for us to provide you with our services. With the usage of our services you permit us to use cookies.
More information Ok