Evolution of instability before and during a torrential rainstorm in North China

详细信息    查看全文

• 作者：Lu Liu ; Lingkun Ran ; Shouting Gao
• 关键词：convective instability ; symmetric instability ; torrential rain ; potential divergence
• 刊名：Advances in Atmospheric Sciences
• 出版年：2016
• 出版时间：January 2016
• 年：2016
• 卷：33
• 期：1
• 页码：110-120
• 全文大小：6,947 KB
• 参考文献：Bennetts, D. A., and B. J. Hoskins, 1979: Conditional symmetric instability-a possible explanation for frontal rainbands. Quart. J. Roy. Meteor. Soc., 105, 945鈥?62.CrossRef
  Bennetts, D. A., and J. C. Sharp, 1982: The relevance of conditional symmetric instability to the prediction of mesoscale frontal rainbands. Quart. J. Roy. Meteor. Soc., 108, 595鈥?02.CrossRef
  Charney, J. G., 1947: The dynamics of long waves in a baroclinic westerly current. J. Meteor., 4, 135鈥?62.CrossRef
  Eady, E. T., 1949: Long waves and cyclone waves. Tellus, 1, 33鈥?2.CrossRef
  Gao, S. T., 2000: The instability of the vortex sheet along the shear line. Adv. Atmos. Sci., 17, 525鈥?37, doi: 10.1007/s00376-000-0016-7.CrossRef
  Gao, S. T., and Y. S. Zhou, 2001: The instability of the vortex sheet along the horizontal shear line. Acta Meteorologica Sinica, 59, 393鈥?04. (in Chinese)
  Hoskins, B. J., 1974: The role of potential vorticity in symmetric stability and instability. Quart. J. Roy. Meteor. Soc., 100, 480鈥?82.CrossRef
  Liu, L., L. K. Ran, Y. S. Zhou, and S. T. Gao, 2014: Analysis on the instability and trigger mechanism of torrential rainfall event in Beijing on 21 July 2012. Chinese J. Atmos. Sci., 39, 583鈥?95, doi: 10.3878/j.issn.1006-9895.1407.14144. (in Chinese)
  Lu, W. S., and H. Y. Shao, 2003: Generalized nonlinear subcritical symmetric instability. Adv. Atmos. Sci., 20, 623鈥?30, doi: 10.1007/BF02915505.CrossRef
  Ran, L. K., L. Liu, N. Li, and Y. B. Qi, 2013: The analysis of the potential-divergence wave activity density and its application to typhoon precipitation. Chinese Journal of Geophysics, 56, 3285鈥?301. (in Chinese)
  Ran, L. K., Y. B. Qi, and S. C. Hao, 2014: Analysis and forecasting of heavy rainfall case on 21 July 2012 with dynamical parameters. Chinese J. Atmos. Sci., 38, 83鈥?00. (in Chinese)
  Schultz, D. M., and P. N. Schumacher, 1999: The use and misuse of conditional symmetric instability. Mon. Wea. Rev., 127, 2709鈥?732.CrossRef
  Schultz, D. M., and J. A. Knox, 2007: Banded convection caused by frontogenesis in a conditionally, symmetrically, and inertially unstable environment. Mon. Wea. Rev., 135, 2095鈥?110.CrossRef
  Seltzer, M. A., R. E. Passarelli, and K. A. Emanuel, 1985: The possible role of symmetric instability in the formation of precipitation bands. J. Atmos. Sci., 42, 2207鈥?219.CrossRef
  Seman, C. J., 1994: A numerical study of nonlinear nonhydrostatic conditional symmetric instability in a convectively unstable atmosphere. J. Atmos. Sci., 51, 1352鈥?371.CrossRef
  Stone, P. H., 1966: On non-geostrophic baroclinic stability. J. Atmos. Sci., 23, 390鈥?00.CrossRef
  Stone, P. H., 1970: On non-geostrophic baroclinic stability: Part II. J. Atmos. Sci., 27, 721鈥?26.CrossRef
  Stone, P. H., 1971: Baroclinic stability under non-hydrostatic conditions. J. Fluid Mech., 45, 659鈥?71.CrossRef
  Sun, J. S., N. He, R. Guo, and M. X. Chen, 2013a: The configuration change and train effect mechanism of multi-cell storms. Chinese J. Atmos. Sci., 37, 137鈥?48. (in Chinese)
  Sun, J. H., S.X. Zhao, S. M. Fu, H. J. Wang, and L. L. Zheng, 2013b: Multi-scale characteristics of record heavy rainfall over Beijing area on July 21, 2012. Chinese J. Atmos. Sci., 37, 705鈥?18. (in Chinese)
  Wang, J. Y., C. G. Cui, X. F. Wang, and W. J. Cui, 2014: Analysis on water vapor transport and budget of the severe torrential rain over Beijing Region on 21 July 2012. Meteorological Monthly, 40, 133鈥?45. (in Chinese)
  Wu, G. X., Y. P. Cai, and X. J. Tang, 1995: Moist potential vorticity and slantwise vorticity development. Acta Meteorologica Sinica, 53, 387鈥?05. (in Chinese)
  Wu, G. X., and Y. P. Cai, 1997: Vertical wind shear and downsliding slantwise vorticity development. Scientia Atmospherica Sinica, 21, 273鈥?82. (in Chinese).
  Wu, G. X., and H. Z. Liu, 1999: Complete form of vertical vorticity tendency equation and slantwise vorticity development. Acta Meteorologica., 57, 1鈥?5. (in Chinese)
  Xu, Q., 1986: Conditional symmetric instability and mesoscale rainbands. Quart. J. Roy. Meteor. Soc., 112, 315鈥?34.CrossRef
  Zhang, K. S., 1988a: On mesoscale instability of a baroclinic flow 1. Symmetric instability. Acta Meteorologica Sinica, 46, 258鈥?66. (in Chinese)
  Zhang, K. S., 1988b: On mesoscale instability of a baroclinic flow 2. transversal instability. Acta Meteorologica Sinica, 46, 385鈥?92. (in Chinese)
  Zhang, L. F., and M. Zhang, 1992: Wave-CISK and symmetric instability. Scientia Atmospherica Sinica, 16, 669鈥?76. (in Chinese)
  
• 作者单位：Lu Liu (1) (2)
  Lingkun Ran (1)
  Shouting Gao (1) (3)
  
  1. Institute of Atmospheric Physics, Chinese Academy Sciences, Beijing, 100029, China
  2. Graduate University of Chinese Academy of Sciences, Beijing, 100040, China
  3. State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing, 100081, China
  
• 刊物主题：Atmospheric Sciences; Meteorology; Geophysics/Geodesy;
• 出版者：Springer Berlin Heidelberg
• ISSN：1861-9533

文摘

NCEP-NCAR reanalysis data were used to analyze the characteristics and evolution mechanism of convective and symmetric instability before and during a heavy rainfall event that occurred in Beijing on 21 July 2012. Approximately twelve hours before the rainstorm, the atmosphere was mainly dominated by convective instability in the lower level of 900鈥?00 hPa. The strong southwesterly low-level jet conveyed the moist and warm airflow continuously to the area of torrential rain, maintaining and enhancing the unstable energy. When the precipitation occurred, unstable energy was released and the convective instability weakened. Meanwhile, due to the baroclinicity enhancement in the atmosphere, the symmetric instability strengthened, maintaining and promoting the subsequent torrential rain. Deriving the convective instability tendency equation demonstrated that the barotropic component of potential divergence and the advection term played a major role in enhancing the convective instability before the rainstorm. Analysis of the tendency equation of moist potential vorticity showed that the coupled term of vertical vorticity and the baroclinic component of potential divergence was the primary factor influencing the development of symmetric instability during the precipitation. Comparing the effects of these factors on convective instability and symmetric instability showed some correlation. Key words convective instability symmetric instability torrential rain potential divergence