Abstract
The quasi-geostrophic Q vector is an important diagnostic tool for studying development of surface rainfall associated with large-scale weather systems and is calculated using data at single vertical level. When ageostrophic Q vector was introduced, it required data at two vertical levels. In this study, moist ageostrophic Q vector is modified so that it can be calculated using data at a single vertical level. The comparison study between the original and modified moist ageostrophic Q vectors is conducted using the data from 5 to 6 July 1991 during the torrential rainfall event associated with the Changjiang-Huaihe mei-yu front in China. The results reveal that divergences of original and modified moist ageostrophic Q vectors have similar horizontal distributions and their centers are almost located in the precipitation centers. This indicates that modified moist ageostrophic Q vector can be used to diagnose convective development with reasonable accuracy.
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Atallah, E., L. F. Bosart, and A. R. Aiyyer. 2007: Precipitation distribution associated with landfalling tropical cyclone over the eastern United States. Mon. Wea. Rev., 135, 2185–2206.
Barnes, S. L., and B. R. Colman, 1993: Quasigeostrophic diagnosis of cyclogenesis associated with a cut off extratropical cyclone—The Christmas 1987 storm. Mon. Wea. Rev., 121, 1613–1634.
Barnes, S. L., and B. R. Colman, 1994: Diagnosing an operational numerical model using Q-vector and potential vorticity concepts. Wea. Forecasting, 9, 85–102.
Brennan, M. J., and G. M. Lackmann, 2006: Observation diagnosis and model forecast evaluation of unforecasted incipient precipitation during the 24–25 January 2000 east coast cyclone. Mon. Wea. Rev., 134, 2033–2054.
Davies-Jones, R., 1991: The frontogenetical forcing of secondary circulations. Part I: the duality and generalization of the Q vector. J. Atmos. Sci., 48, 497–509.
Ding, Y., 1989: Diagnostic and Analytical Methods in Synoptic Dynamics. Science Press, Beijing, 114–116. (in Chinese)
Donnadille, J., J.-P. Cammas, P. Mascart, and D. Lambert, 2001: FASTEX IOP 18: A very deep tropopause fold. II: Quasi-geostrophic omega diagnoses. Quart. J. Roy. Meteor. Soc., 127, 2269–2286.
Dunn, L. B., 1991: Evaluation of vertical motion: Past, Present, and Future. Wea. Forecasting, 6, 65–73.
Dutton, J. A., 1976: The Ceaseless Wind. McGraw-Hill, 579pp.
Gao, S., 2007: Dynamical Basis and Forecast Methods of Atmospheric Meso-scale Motion. China Meteorological Press, Beijing, 191–200. (in Chinese)
Guo, R., Y. Lu, Y. Li, Y. Hai, and M. Gao, 2005a: Analyses of a Yunnan rainstorm process influenced by the “Imbudo” typhoon. Plateau Meteorology, 24, 784–791. (in Chinese)
Guo, R., Y. Li, X. Yang, and C. Zhou, 2005b: Nongeostrophic wet Q-vector analysis and application of heavy precipitation in winter in Yunnan. Meteorological Monthly, 31, 12–16. (in Chinese)
Hoskins, B. J., I. Dagbici, and H. C. Darics, 1978: A new look at the ω-equation. Quart. J. Roy. Metor. Soc., 104, 31–38.
Jurewicz, M. L., and M. S. Evans. 2004: A comparison of two banded, heavy snowstorms with very different synoptic settings. Wea. Forecasting, 19, 1011–1028.
Jusem, J. C., and R. Atlas, 1998: Diagnostic evaluation of vertical motion forcing mechanism by using Q-vector partitioning. Mon. Wea. Rev., 126, 2166–2184.
Keyser, D., M. J. Reeder, and R. J. Reed, 1988: A generalization of Petterssen’s frontogenesis function and its relation to the forcing of vertical motion. Mon. Wea. Rev., 116, 762–780.
Keyser, D., B. D. Schmidt, and D. G. Duffy, 1992: Quasigeostrophic vertical motions diagnosed from along-and cross-isentrope components of the Q vector. Mon. Wea. Rev., 20, 731–741.
Kurz, M., 1992: Synoptic diagnosis of frontogenetic and cyclogenetic processes. Meteorology and Atmospheric Physics, 48, 77–91.
Li, B., and G. Li, 1997: Application of the semi-geostrophic Q vector in study of the mei-yu front heavy rain. Atmospheric Science Research and Application, 12, 31–38. (in Chinese)
Li, Y., T. Zhang, and R. Guo, 2002: Ageostrophic wet Q vector analysis of a persistent rainstorm process in Yunnan. Journal of Nanjing Institute of Meteorology, 25, 259–264. (in Chinese)
Li, Y., L. Ji, X. Pan, and Y. Li, 2005: Analysis by diagnosis of wet Q vector of a rainstorm process. Scientia Meteorologica Sinica, 25, 179–185. (in Chinese)
Liu, Y., 2006: Wet Q-vector analysis of a continued heavy rain process over the eastern Qinghai-Xizang plateau. Meteorological Monthly, 32, 43–49. (in Chinese)
Liu, H., S. Shou, and J. Zhou, 2007: Improvement and application of ageostrophic wet Q-vector. Journal of Nanjing Institute of Meteorology, 30, 86–93. (in Chinese)
Liu, Z., C. Yue, S. Shou, and M. Dong, 2003: Using wet Q vector to diagnose a process of mei-yu front heavy rain. Journal of Nanjing Institute of Meteorology, 26, 102–110. (in Chinese)
Lynch, A. H., E. N. Cassano, J. J. Cassano, and L. R. Lestak. 2003: Case studies of high wind events in Barrow, Alaska: Climatological context and development processes. Mon. Wea. Rev., 131, 719–732.
Martin, J. E., 1999a: Quasi-geostrophic forcing of ascent in the occluded sector of cyclones and the trowal airstream. Mon. Wea. Rev., 127, 70–88.
Martin, J. E., 1999b: The separate roles of geostrophic vorticity and deformation in the midlatitude occlusion process. Mon. Wea. Rev., 127, 2404–2418.
Martin, J. E., 2006: The role of shearwise and transverse quasigeostrophic vertical motions in the midlatitude cyclone life cycle. Mon. Wea. Rev., 134, 1174–1193.
Martin, J. E., 2007: Lower-tropospheric height tendencies associated with the shearwise and transverse components of quasigeostrpphic vertical motion. Mon. Wea. Rev., 135, 2803–2809.
Morgan, M. C., 1999: Using piecewise potential vorticity inversion to diagnose frontogenesis. Part I: A partitioning of the Q vector applied to diagnosing surface frontogenesis and vertical motion. Mon. Wea. Rev., 127, 2796–2821.
Pyle, M. E., D. Keyser, and L. F. Bosart, 2004: A diagnostic study of jet streaks: Kinematic signatures and relationship to coherent tropopause disturbances. Mon. Wea. Rev., 132, 297–319.
Schar, C., and H. Wernli, 1993: Structure and evolution of an isolated semi-geostrophic cyclone. Quart. J. Roy. Meteor. Soc., 119, 57–90.
Shou, S., and Y. Li, 1999: Study on moist potential vorticity and symmetric instability during a heavy rain event occurred in the Jiang-Huai valleys. Adv. Atmos. Sci., 16, 314–321.
Shou, S., Y. Li, and K. Fan, 2001: Isentropic potential vorticity analysis of the mesoscale cyclone development in a heavy rain process. Acta Meteorologica Sinica, 59, 560–568. (in Chinese)
Tao, Z., and W. Huang, 1994: 3-D trajectory analysis of air parcel associated with high and low level jets in heavy rain. Acta Meteorologica Sinica, 52, 359–367. (in Chinese)
Thomas, B. C., and J. E. Martin, 2007: A synoptic climatology and composite analysis of the Alberta Clipper. Wea. Forecasting, 22, 315–333.
Xu, Q., 1992: Ageostrophic pseudovorticity and geostrophic C-vector forcing—A new look at Q vector in three dimensions. J. Atmos. Sci., 49, 981–990.
Yan, Q., and Q. Cai, 2006: Application of ageostrophic wet Q-vector analysis in torrential rain of typhoon “Rananim”. Journal of Tropical Meteorology, 22, 505–509. (in Chinese)
Yang, S., S. Gao, and D. Wang, 2007: Diagnostic analyses of the ageostrophic Q vector in the non-uniformly saturated, frictionless, and moist adiabatic flow. J. Geophys. Res., 112(D09114), 1–9, doi:10.1029/2006JD008142.
Yang, X., T. Shen, H. Liu, D. Xue, and F. Wan, 2006: Application of the wet Q vector partitioning method to the diagnosis of the heavy rainstorm. Plateau Meteorology, 25, 464–475. (in Chinese)
Yao, X., and Y. Yu, 2000: Non-geostrophic wet Q-vector analysis and its application to typhoon torrential rain. Acta Meteorologica Sinica, 58, 436–446. (in Chinese)
Yao, X., and Y. Yu, 2001: Perfect Q-vector and its diagnoses. Plateau Meteorology, 20, 208–213. (in Chinese)
Yao, X., Y. Yu, and S. Shou, 2004: Diagnostic analyses and application of the moist ageostrophic Q vector. Adv. Atmos. Sci., 21, 96–102.
Yue, C., S. Shou, and M. Dong, 2003a: Quantitative analysis of several Q vectors. Journal of Applied Meteorological Science, 14, 39–48. (in Chinese)
Yue, C., S. Shou, K. Lin, and X. Yao, 2003b: Diagnosis of the heavy rain near a mei-yu front using the wet Q vector partitioning method. Adv. Atmos. Sci., 20, 37–44.
Yue, C., Y. Shou, and S. Shou, 2003c: The improvement and perfection of Q vector. Journal of Tropical Meteorology, 19, 308–316. (in Chinese)
Yue, C., M. Dong, S. Shou, and X. Yao, 2007a: Improved wet Q vector’s analytical method and the mechanism of mei-yu front rainstorm genesis. Plateau Meteorology, 26, 165–175. (in Chinese)
Yue, C., Y. Shou, S. Shou, G. Zeng and Y. Wang, 2007b: Study on wet Q vector interpretation technique with its application to quantitative precipitation forecast (QPF). Journal of Applied Meteorological Science, 18, 666–675. (in Chinese)
Zhang, X., 1998: An expression of the wet Q vector and application. Meteorological Monthly, 24, 3–7. (in Chinese)
Zhang, X., 1999: The expression of the modified Q vector and its application. Journal of Tropical Meteorology, 15, 162–167. (in Chinese)
Zhao, G., L. Cheng, and X. Li, 2006: Comparison and application of Q-vector and wet-Q-vector to diagnosis of storm rain. Meteorological Monthly, 32, 25–30. (in Chinese)
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Yue, C., Shou, S. A modified moist ageostrophic Q vector. Adv. Atmos. Sci. 25, 1053–1061 (2008). https://doi.org/10.1007/s00376-008-1053-x
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DOI: https://doi.org/10.1007/s00376-008-1053-x