-
Abstract:
In this paper, statistics were analyzed concerning correlation between the storm rainfall far from typhoon and non-zonal upper-level jet stream. The results show that the jet stream at 200 hPa is constantly SW (90.2 %) during the period in which storm rainfall occurs. Rainfall area lies in the right rear regions of the jet axes. While the storm intensifies, the jet tends to be stronger and turn non-zonal. With the MM4 model, numerical simulation and diagnosis were carried out for Typhoon No.9711 (Winnie) on August 19 to 20, 1997. The distant storm rainfall is tightly correlative to the jet and low-level typhoon trough. The divergence field of jet is related to the v component. The upper level can cause the allobaric wind convergence at low level. This is the result of the form of low-level typhoon trough and the strength of the storm. By scale analysis, it is found that there is a branch of middle scale transverse inverse circulation in the right entrance regions behind the jet below the 300-hPa level, which is very important to the maintenance and strengthening of storm rainfall. This branch of inverse circulation is relative to the reinforcement of jet's non-zonal characteristics. From the field of mesoscale divergence field and non-zonal wind field, we know that the stronger symmetry caused by transverse circulation in the two sides of the jet, rainfall’s feedback and reinforcement of jet’s non-zonal characteristics had lead to positive feedback mechanism that was favorable of storm rainfall’s strengthening.
-
References
|
[1]
|
UCCELLINI L W, JHONSON D R. The coupling of upper and lower tropospheric jet stream and implicationfor the development of severe convective storm [J]. Monthly Weather Review, 1979, 107: 682-703. |
|
[2]
|
HUANG An-li, GAO Kun. Dynamical analysis of upper and lower level tropospheric jet streaks [J]. Journalof Hangzhou University, 1982, 9: 356-364. |
|
[3]
|
DING Zhi-ying, CHEN Jiu-kang. Diagnosis, comparative analysis and simulation of typhoons with differentrainfall intensities [J]. Journal of Nanjing Institute of Meteorology, 1995, 18(2): 234-241. |
|
[4]
|
LUO Ya-li, DING Yi-hui, YI Qing-ju. Heavy Rain in the Situation of Typhoon Landfall [A]. DING Yi-hui.Research on Mesoscale Weather and Dynamics [C]. Beijing: Meteorological Press, 1996. 60-92. |
|
[5]
|
LU Shen-shen, SHOU Shao-wen. Energetic analysis of maintenance and rainfall amplification of landedtyphoons [J]. Journal of Nanjing Institute of Meteorology, 1995, 18(3): 383-388. |
|
[6]
|
JIANG Shang-cheng. A synoptic model of the hardrain storm in westerly belt affected by the far distant typhoon[J]. Acta Meteorologica Sinica, 1983, 41(6): 147-158. |
|
[7]
|
ZHU Qian-gen, LIN Jin-rui, SHOU Shao-wen, et al. Principles and Methodology of Synoptics [M]. Beijing:Meteorological Press, 1992. 718-719. |
|
[8]
|
ANTHES R A, HSIE E Y, KUO Y-H. Description of the Penn state/NCAR mesoscale model version4(MM4)[B]..NCAR Technical Note, NCAR/TN-82+STR[R]. 1987. 66. |
|
[9]
|
Kuo Y H. On formation and intensification of tropical cyclones through latent heat release by cumulus convection[J]. J Atmospheric Sciences,1965, 22: 40－63. |
|
[10]
|
DING Zhi-ying, CHEN Jiu-kang, LU Jun-ning. The relation between heavy rain and large-scale gravity-inertia internal wave in the 200 hPa upper tropospheric jet [J]. Journal of Nanjing Institute of Meteorology,1992, 15(2): 101-110. |
|
[11]
|
XIA Da-qing, ZHENG Liang-jie, DONG Shuang-lin, et al. Some operators for separating meso-scale meteorologicalfields and their comparisons [J]. Scientia Atmospherica Sinica, 1983, 7(3): 303-311. |
|
[12]
|
CHEN Jiu-kang, DING Zhi-ying. Mesoscale heavy rain systems with the coupling of upper and lowerlevel jets and typhoon circulation [A]. DING Yi-hui. Research on Mesoscale Weather and Dynamics [C].Beijing: Meteorological Press, 1996. 171-179. |
-
-
-
粤公网安备 4401069904700002号
DownLoad: