Development and Evaluation of an Ensemble-Based Data Assimilation System for Regional Reanalysis Over the Tibetan Plateau and Surrounding Regions

Jie He, Fuqing Zhang, Xingchao Chen, Xinghua Bao, Deliang Chen, Hyun Mee Kim, Hui Wen Lai, L. Ruby Leung, Xulin Ma, Zhiyong Meng, Tinghai Ou, Ziniu Xiao, Eun Gyeong Yang, Kun Yang

Research output: Contribution to journalArticle

Abstract

The Tibetan Plateau is regarded as the Earth's Third Pole, which is the source region of several major rivers that impact more 20% the world population. This high-altitude region is reported to have been undergoing much greater rate of weather changes under global warming, but the existing reanalysis products are inadequate for depicting the state of the atmosphere, particularly with regard to the amount of precipitation and its diurnal cycle. An ensemble Kalman filter (EnKF) data assimilation system based on the limited-area Weather Research and Forecasting (WRF) model was evaluated for use in developing a regional reanalysis over the Tibetan Plateau and the surrounding regions. A 3-month prototype reanalysis over the summer months (June−August) of 2015 using WRF-EnKF at a 30-km grid spacing to assimilate nonradiance observations from the Global Telecommunications System was developed and evaluated against independent sounding and satellite observations in comparison to the ERA-Interim and fifth European Centre for Medium-Range Weather Forecasts Reanalysis (ERA5) global reanalysis. Results showed that both the posterior analysis and the subsequent 6- to 12-hr WRF forecasts of the prototype regional reanalysis compared favorably with independent sounding observations, satellite-based precipitation versus those from ERA-Interim and ERA5 during the same period. In particular, the prototype regional reanalysis had clear advantages over the global reanalyses of ERA-Interim and ERA5 in the analysis accuracy of atmospheric humidity, as well as in the subsequent downscale-simulated precipitation intensity, spatial distribution, diurnal evolution, and extreme occurrence.

Original languageEnglish (US)
Pages (from-to)2503-2522
Number of pages20
JournalJournal of Advances in Modeling Earth Systems
Volume11
Issue number8
DOIs
StatePublished - Aug 1 2019

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All Science Journal Classification (ASJC) codes

  • Global and Planetary Change
  • Environmental Chemistry
  • Earth and Planetary Sciences(all)

Cite this

He, J., Zhang, F., Chen, X., Bao, X., Chen, D., Kim, H. M., Lai, H. W., Leung, L. R., Ma, X., Meng, Z., Ou, T., Xiao, Z., Yang, E. G., & Yang, K. (2019). Development and Evaluation of an Ensemble-Based Data Assimilation System for Regional Reanalysis Over the Tibetan Plateau and Surrounding Regions. Journal of Advances in Modeling Earth Systems, 11(8), 2503-2522. https://doi.org/10.1029/2019MS001665