Advances in Atmospheric Sciences

, Volume 27, Issue 5, pp 1025–1042 | Cite as

Radar data assimilation for the simulation of mesoscale convective systems

  • Jo-Han Lee
  • Hyun-Ha Lee
  • Yonghan Choi
  • Hyung-Woo Kim
  • Dong-Kyou LeeEmail author


A heavy rainfall case related to Mesoscale Convective Systems (MCSs) over the Korean Peninsula was selected to investigate the impact of radar data assimilation on a heavy rainfall forecast. The Weather Research and Forecasting (WRF) three-dimensional variational (3DVAR) data assimilation system with tuning of the length scale of the background error covariance and observation error parameters was used to assimilate radar radial velocity and reflectivity data. The radar data used in the assimilation experiments were preprocessed using quality-control procedures and interpolated/thinned into Cartesian coordinates by the SPRINT/CEDRIC packages. Sensitivity experiments were carried out in order to determine the optimal values of the assimilation window length and the update frequency used for the rapid update cycle and incremental analysis update experiments.

The assimilation of radar data has a positive influence on the heavy rainfall forecast. Quantitative features of the heavy rainfall case, such as the maximum rainfall amount and Root Mean Squared Differences (RMSDs) of zonal/meridional wind components, were improved by tuning of the length scale and observation error parameters. Qualitative features of the case, such as the maximum rainfall position and time series of hourly rainfall, were enhanced by an incremental analysis update technique. The positive effects of the radar data assimilation and the tuning of the length scale and observation error parameters were clearly shown by the 3DVAR increment.

Key words

WRF 3DVAR 3DVAR cycling initialization tuning heavy rainfall radar data 


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Copyright information

© Chinese National Committee for International Association of Meteorology and Atmospheric Sciences, Institute of Atmospheric Physics, Science Press and Springer-Verlag Berlin Heidelberg 2010

Authors and Affiliations

  • Jo-Han Lee
    • 1
  • Hyun-Ha Lee
    • 1
  • Yonghan Choi
    • 1
  • Hyung-Woo Kim
    • 1
  • Dong-Kyou Lee
    • 1
    Email author
  1. 1.School of Earth and Environmental SciencesSeoul National UniversitySeoulKorea

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