Abstract
During the mei-yu period, the east edge of the Tibetan Plateau and the Dabie Mountain are two main sources of eastward-moving mesoscale vortices along the mei-yu front (MYF). In this study, an eastward-moving southwest vortex (SWV) and an eastward-moving Dabie vortex (DBV) during the mei-yu period of 2010 have been investigated to clarify the main similarities and differences between them. The synoptic analyses reveal that the SWV and DBV were both located at the lower troposphere; however, the SWV developed in a “from top down” trend, whereas the DBV developed in an opposite way. There were obvious surface closed low centers corresponding to the DBV during its life span, whereas for the SWV, the closed low center only appeared at the mature stage. Cold and warm air intersected intensely after the formation of both the vortices, and the cold advection in the SWV case was stronger than that in the DBV case, whereas the warm advection in the DBV case was more intense than that in the SWV case. The Bay of Bengal and the South China Sea were main moisture sources for the SWV, whereas for the DBV, in addition to the above two moisture sources, the East China Sea was also an important moisture source. The vorticity budget indicates that the convergence was the most important common factor conducive to the formation, development, and maintenance of the SWV and DBV, whereas the conversion from the vertical vorticity to the horizontal one (tilting) was the most important common factor caused the dissipation of both of the vortices. The kinetic energy (KE) budget reveals that the KE generation by the rotational wind was the dominant factor for the enhancement of KE associated with the SWV, whereas for the DBV, the KE transport by the rotational wind was more important than the KE generation. The KE associated with the SWV and the DBV weakened with different mechanisms during the decaying stage. Furthermore, the characteristics of baroclinic and barotropic energy conversions during the life spans of both vortices indicate that the SWV and DBV both belong to the kind of subtropical mesoscale vortices.
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References
Tao S Y. Rainstorms in China (in Chinese). Beijing: Science Press, 1980. 1–225
Akiyama T. A medium scale cloud cluster in a baiu front, Part I: Evolution process and fine structure. J Meteor Soc Jpn, 1984, 62: 485–504
Ninomiya K, Akiyama T, Ikawa M. Evolution and fine structure of a long-lived meso-α-scale convective system in a baiu front zone, Part I: Evolution and meso-β-scale characteristics. J Meteor Soc Jpn, 1988, 66: 331–350
Ninomiya K. Large-and meso-α-scale characteristics of meiyu/baiu front associated with intense rainfalls in 1–10 July 1991. J Meteor Soc Jpn, 2000, 78: 141–157
Chen Q Z, Huang Y W, Wang Q W, et al. The statistical study of the southwest vortexex during 1990–2004 (in Chinese). J Nanjing Univ (Natural Sci), 2007, 43: 633–642
Chen Z M, Min W B. Statistics analysis of southwest vortex (in Chinese). The Secondary Proceedings of Qingzang Plateau Meteorology Conference, 2000. 368–378
Ding Y H. Study on the Lasting Heavy Rainfalls over the Yangtze-Huaihe River Basin in 1991 (in Chinese). Beijing: Chinese Meteorological Press, 1993. 255
Dong P M, Zhao S X. A diagnostic study of mesoscale lows (disturbances) on Meiyu front and associated heavy rainfall (in Chinese). Chin J Atmos Sci, 2004, 28: 876–891
Dong P M, Zhao S X. A numerical study of two kinds of mesoscale low (disturbance) on Meiyu front and associated heavy rainfall. Clim Environ Res, 2004, 9: 641–657
Fu S M. Study on the structure characteristics and formation mechanism of southwest vortex with heavy rainfall (in Chinese). Dissertation for the Doctoral Degree. Beijing: Institute of Atmospheric Physics, Chinese Academy of Sciences, 2009
Lu J H. Generality of the Southwest Vortex (in Chinese). Beijing: China Meteorological Press, 1986. 1–270
Wang Z, Gao K. Sensitivity experiments of an eastward-moving southwest vortex to initial perturbations. Adv Atmos Sci, 2003, 20: 638–649
Hu B W, Pan E F. Two kinds of cyclonic disturbances and their accompanied heavy rain in the Yangtze River Valley during the Meiyu period (in Chinese). J Appl Meteorol Sci, 1996, 7: 138–144
Yang Y M, Gu W L, Zhao R L, et al. The statistical analysis of low vortex during Meiyu season in the lower reaches of the Yangtze (in Chinese). J Applied Meteorol Sci, 2010, 21: 11–18
Gao K, Xu Y M. A simulation study of structure of meso vortices along Meiyu front during 22–30 June 1999 (in Chinese). Chin J Atmos Sci, 2001, 25: 740–756
Ma L M, Qin Z H, Duan Y H, et al. Case study on the impact of atmospheric baroclinicity to the initial development of Jianghuai Cyclones (in Chinese). Acta Oceanol Sin, 2002, 24: 95–104
Sun J H, Zhao S X, Xu G K, et al. Study on a mesoscale convective vortex causing heavy rainfall during the meiyu season in 2003. Adv Atmos Sci, 2010, 27: 1193–1209
Sun S Q, Du C X. The maintenance of Meiyu front and development associated disturbance (in Chinese). J Appl Meteorol Sci, 1996, 7: 153–159
Yao X P, Wu G X, Zhao B K, et al. Research on the dry intrusion accompanying the low vortex precipitation. Sci China Ser D-Earth Sci, 2007, 50: 1396–1408
Zhai G Q, Wang Z, He B. Formation and evolution analysis of the mesoscale vortex group in the middle and lower reaches during meiyu of the Yangtze River (in Chinese). Acta Meteorol Sin, 2003, 61: 661–672
Zhai G Q, Zhou L L, Wang Z. Analysis of a group of weak small-scale vortices in the planetary boundary layer in the meiyu front. Adv Atmos Sci, 2007, 24: 399–408
Chen L F, Gao K. The structure of meiyu front and the relationship between the front and the vortex disturbance along it (in Chinese). Chin J Atmos Sci, 2007, 31: 863–875
Joyce R J, Janowiak J E, Arkin P A, et al. CMORPH: A method that produces global precipitation estimates from passive microwave and infrared data at high spatial and temporal resolution. J Hydromet, 2004, 5: 487–503
Kirk J R. A phase-plot method for diagnosing vorticity concentration mechanisms in mesoscale convective vortices. Mon Weather Rev, 2007, 135: 801–820
Chen T C, Alpert J C, Schlatter T W. The effects of divergent and nondivergent winds on the kinetic energy budget of a mid-latitude cyclone: A case study. Mon Weather Rev, 1978, 106: 458–468
Fu S M, Sun J H, Zhao S X, et al. The energy budget of a southwest vortex with heavy rainfall over south China. Adv Atmos Sci, 2011, 28: 709–724
Ding Y H, Liu Y Z. On the analysis of Typhoon kinetic energy, part II: Conversion between divergent and nondivergent wind (in Chinese). Sci China Ser B, 1985, 11: 1045–1054
Fu S M, Sun J H, Zhao S X, et al. The impact of the eastward propagation of convective systems over the Tibetan Plateau on the southwest vortex formation in summer. Atmos Oceanic Sci Lett, 2010, 3: 51–57
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Fu, S., Yu, F., Wang, D. et al. A comparison of two kinds of eastward-moving mesoscale vortices during the mei-yu period of 2010. Sci. China Earth Sci. 56, 282–300 (2013). https://doi.org/10.1007/s11430-012-4420-5
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DOI: https://doi.org/10.1007/s11430-012-4420-5