Urban impacts on summertime
rainfall in Beijing
PEI Grand Challenges program and MIRTHE
(Mid Infrared Technologies for Health and Environment)
Summer 2008
Raleigh Martin ‘08
Understanding the effects of air
pollution on Beijing’s climate
Project components
1. Air-quality monitoring (QCLOPS and NO
sensor)
2. Analysis of meteorological data
3. Review of existing studies
4. Atmospheric modeling using WRF
Study region
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Monsoon climate: cold dry
winters and hot moist summers.
Mean annual precipitation = 570
mm/yr
June-July-August precipitation =
420 mm/yr
Average 2.1 days per year with
precipitation over 50 mm
(Wang and Li, 2007)
Rapid urbanization and declining
precipitation in Beijing
13.3 km2/yr
increase in
urbanized area
10.5 mm/yr decrease in
summer precipitation
12.4 mm/yr decrease in
summer precipitation
near Miyun Reservoir
(Zhang et al. 2007)
Literature Review
 Most studies of Beijing’s climate are in Chinese!!!
Main points from review:
- Growing urban heat island since 1975 (Sun and
Shu 2007) and effects of urban heat fluxes on
storms (Zhang et al. 2007)
- Importance of orography (Zhang et al. 2005)
- Short thunderstorm life-cycle, low-level
convergence and upper-level divergence,
importance of wind shear (Fu and Guo 2007,
Zheng and Zhang 2007, He et al. 2007)
WRF 2-domain:
WRF modeling
 Problems of model
sensitivity to storms
 Sensitivity analyses to
better understand model
function
Mao et al. 2008:
WRF 4-domain:
Thanks to the MIRTHE Beijing
team!
References
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Fu, D., Guo, X., 2007. Numerical Study on a Severe Downburst-Producing Thunderstorm on 23
August 2001 in Beijing (English). Advances in Atmospheric Sciences 22 (2).
He, L., Chen, T., Zhou, Q., Li, Z., 2007. The Meso-β Scale Convective System of a Heavy Rain
Event on July 10, 2004 in Beijing (Chinese). Journal of Applied Meteorological Science 18 (5).
Mao, D., Qiao, L., Chen, T., Xu, H., Yang, K., 2008. Numerical Simulation and Analysis of a Local
Storm in Beijing on 10 July 2004 (Chinese). Meteorological Monthly 34 (2).
Sun, J., Shu, W., 2007. The Effect of Urban Heat Island on Winter and Summer Precipitation in
Beijing Region (Chinese). Chinese Journal of Atmospheric Sciences 31 (2).
Wang, S., Li, W. (Eds.), 2007. Climate of China. China Meteorological Press.
Zhang, C., Li, C., Kuo, Y.-H., Fan, S., Xuan, C., Chen, M., 2005. Numerical Simulation and Analysis
of The Effect of Orography on the ﾒ00.7ﾓ Thunder- storm in Beijing (Chinese). Advances in Natural
Sciences 15 (5).
Zhang, C., Miao, S., Li, Q., Chen, F., 2007. Impacts of fine-resolution land use information of Beijing
on a summer severe rainfall simulation (Chinese). Chinese Journal of Geophysics 50 (5).
Zhang, C., Chen, F., Mia, S., Li, Q., Xuan, C., 2007. Influences of urbanization on precipitation and
water resources in the metropolitan Beijing area. The 87th AMS Annual Meeting (San Antonio, TX).
Zheng, Z., Zhang, X., 2007. Numerical Study on Relationship between Low Level Jet and Local
Heavy Rain in Beijing (Chinese). Journal of Nanjing Institute of Meteorology 30 (4).