Chang C. P., L. Yi, and G .T. J. Chen, 2000: A numerical simulation of vortex development during the 1992 East Asian summer monsoon onset using Navy's regional model. Mon. Wea. Rev., 128, 1604- 1631.10.1175/1520-0493(2000)1282.0.CO;25053c98f-5c68-4113-95fd-30729b1d468d7e580e3c50f75c919b5bab32a3aff4a4http://connection.ebscohost.com/c/articles/6408396/numerical-simulation-vortex-development-during-1992-east-asian-summer-monsoon-onset-using-navy-s-regional-modelhttp://connection.ebscohost.com/c/articles/6408396/numerical-simulation-vortex-development-during-1992-east-asian-summer-monsoon-onset-using-navy-s-regional-modelAbstract Significant rainfall of the east Asian summer monsoon is produced by low-level disturbances moving eastward in the vicinity of the Yangtze River valley. Many of these disturbances appeared to originate from stationary vortices east of the Plateau of Tibet. Previous studies found latent heating to be the dominant energy source for the development of these vortices during mature monsoon. This work uses the navy regional forecast model to study the development of a disturbance system during 15-17 May 1992, around the beginning of the monsoon season. The system was characterized by a preexisting stationary vortex in the Sichuan basin and the subsequent development of another vortex that propagated eastward along a Mei-yu front that moved into the Yangtze River valley. The numerical simulation, in conjunction with an analysis of the ECMWF data using a potential vorticity inversion, indicates that during the first 24 h the stationary vortex was maintained by terrain effects. On 16 May, the forcings of an upper-level jet and a shortwave 500-hPa trough, along with latent heat release that may have been triggered by the upper forcings, intensified this vortex temporarily. Afterward, the vortex continued to develop by a low-level front errain interaction in which the frontal secondary circulation turned the basin-scale east est overturning counterclockwise while the low-level vertical easterly shear was enhanced. This configuration tilted the vertical shear into a source of cyclonic vorticity. The upper-level forcings and the associated latent heat release also spun up the eastward propagating vortex, whose subsequent intensification was mainly the result of latent heat release along the front. Sensitivity experiments indicate that the terrain effect is crucial for the vortex development within the Sichuan basin. In addition, forcing of the cold air southward by the terrain, and enhancement of the secondary frontal circulation by condensation heating, were required for the low-level front to move sufficiently southward into the Yangtze River region to produce the development of the propagating disturbance. If the front stayed in a more northerly position, the disturbance would move eastward too fast to accumulate the moisture for heavy rainfall and latent heat release. Because of the close proximity of the two vortices and the sequence of development, it may appear in the weather maps that the second vortex was originated from the first. However, the present results indicate that the propagating disturbance was a separate development rather than an eastward migration or a split of the stationary vortex in the Sichuan basin.
Chen D., Y. Q. Li, and R. H. Huang, 2007a: The physical process analyses of the southwest vortex development and its effect on heavy rainfall in eastern Sichuan under the saddle pattern background of large scale circulations. Chinese J. Atmos. Sci., 31, 185- 201. (in Chinese)10.1002/jrs.1570582b6f09-8ae1-416e-aee6-0f76ca72f080f99ee5b7c0f8d384b0e0f95027f8402ahttp://en.cnki.com.cn/Article_en/CJFDTOTAL-DQXK200702001.htmhttp://en.cnki.com.cn/Article_en/CJFDTOTAL-DQXK200702001.htmThe characteristics of large-scale circulation background and the physical process of the southwest vortex during the occurring period of heavy rainfall in the eastern Sichuan basin from 6 July to 9 July 2005 are analyzed from large-scale circulations, water vapor transport and temperature advection by using the observed data and are diagnosed from the vertical and horizontal components of moist potential vorticity, i.e., Pm1 and Pm2, respectively. The analyzed results are shown as follows: (1) During the period of heavy rainfall, the northern part of Sichuan basin was continuously influenced by some low-pressure troughs separated from the eastward propagation and adjustment of atmospheric long-waves at middle and high latitudes, and the Bay of Bangal monsoon trough located to the southwest of the basin was more active. At the same time, Influenced by the westerly wind zone in the process of the northward transport of the South China Sea monsoon, a cyclonic distribution was also formed in the southeast part of the Sichuan basin. Moreover, the western Pacific subtropical high shifted westward to the west of the Sichuan basin, and the Tibetan high was formed over the middle part of the Tibetan Plateau. Thus, a saddle pattern disposition of large-scale circulations was formed. (2) Under the background of the saddle pattern disposition of large-scale circulations, strong southwesterly flow could directly enter the basin around the east of the Tibetan Plateau, and weak southwesterly flow also could enter the eastern Sichuan basin over the Yunnan-Guizhou Plateau, which formed a convergent zone of northward jet stream in the east of the Sichuan basin due to the stopping effect of topography and the effect of the westward shift of the western Pacific subtropical high. Moreover, since these two flows also transported a great amount of water vapor, a convergent area of warm and wet air with high temperature and humidity was caused in the northeast of the Sichuan basin. (3) It can be shown from the diagnosis of the vertical and horizontal components of moist potential vorticity that during the occurring period of heavy rainfall, since dry air continuously entered the upper level over the Sichuan basin, the strong instability of vertical convection, i.e., Pm10, was caused over the basin and developed toward the northeast of the basin, which made the continuous intensification of cyclonic vorticity, i.e., a low vortex strongly developed over the area. Moreover, the horizontal gradient of equivalent potential temperature of warm and wet air in the low level over the Sichuan basin, which can caused Pm20, also played an important role in the development of the southwest vortex and the occurrence of heavy rainfall, and the center of positive Pm2 was also in good agreement with the area of heavy rainfall. This shows that heavy rainfall used to occur in the instable region of vertical convection of air with high temperature and humidity.
Chen L. S., J. X. Ma., and Z. X. Luo, 2000: A Preliminary study on the movement of vortex over the orography. The Second Theoretic Research Advance of Tibetan Plateau Atmosphere III. Tao et al., Eds., China Meteorological Press, Beijing, 90- 97. (in Chinese)
Chen L. F., K. Gao, and Y. M. Xu, 2004: Relationship between the evolvement of Meiyu front and the vortex along it. Journal of Zhejiang University (Science Edition), 31, 103- 109. (in Chinese)10.1007/BF0287309520b8e642-9d8f-4e55-b426-d73e7b6b7d8aec53bc1aace6c9a8e235cce6856bb02dhttp%3A%2F%2Fen.cnki.com.cn%2FArticle_en%2FCJFDTotal-HZDX200401023.htmhttp://en.cnki.com.cn/Article_en/CJFDTotal-HZDX200401023.htmThe Meso-scale model MM5 were used to analyse the two vortexes that occurred during June 26 to July 1 in 1999. It was found that there is a close relation between them. 750 hPa was the level that the front was the strongest. The front developed most was just of the north where the low vortex developed most. The frontogengsis was about 15 hours earlier than the development of the low vortex. Frontogenesis propagated from west to east, and it was more apparent when the low vortex was developing. The front moved northward before the low vortex passed, and moved southward after the later passed. Furthermore, the slope of the front became large before the low vortex passed, and became small after it passed, and was almost vertical when the vortex passing along it. The shift rang of the front in the place where the low vortex was developing was wider than that in the other places.
Chen Q. Z., Y. W. Huang, Q. W. Wang, and Z. M. Tan, 2007b: The statistical study of the southwest vortexes during 1990-2004. Journal of Nanjing University (Natural Sciences), 43, 633- 642. (in Chinese)10.1002/jrs.157091c0082e-0489-472c-a45d-91758581616965d7a05b8f53bc727511f4dbc0156abfhttp://en.cnki.com.cn/Article_en/CJFDTOTAL-NJDZ200706007.htmhttp://en.cnki.com.cn/Article_en/CJFDTOTAL-NJDZ200706007.htmIn this paper,the characteristics of the southwest vortexes are statistically studied using the daily weather map data from 1990 to 2004.The main results are shown:(1) The frequency of the southwest vortexes change greatly at different seasons,there are total 262 vortexes whose lives sustain more than one day,and it is of high frequency in spring and summer,respectively with 77 vortexes(29.4% of the total) and 92 vortexes(35.1% of the total).The frequency is lower in autumn and winter,and the vortexes are 55(21.0% of the total) and 38(14.5% of the total),respectively.(2) There are two main regions for the generation of the southwest vortex.One is along the southeast edge of the Tibet Platean and the other is in the Sichuan Basin,and the former is the most important region,when compared with the latter.(3) The lifecycle of most vortexes is shorter than one day,whose number is about 776 and is 74.8% of the total.About 239 vortexes(23.0% of the total) could sustain 1 to 3 days,21(2.0% of the total) can sustain 3 to 6 days,only 2 could undergo 6 to 7 days.(4) Only 6% of the total southwest vortexes can move out of their generation regions,and the moving tracks can be roughly classified into four kinds,the northeast track(33.3% of the total moving vortexes),the eastward track(50.0% of the total moving vortexes),the southeast track(5.0% of the total moving vortexes) and the quasi-stationary track(11.7% of the total moving vortexes),respectively.(5) The intensity distribution of the southwest vortexes increases obviously from the south to the north,while changes slightly from the west to the east,strengthening first and then weakening appreciably.
Chen Z. M., 1990: A dynamic mechanism of on the formation and development of the southwest vortex. Journal of Sichuan Meteorology, 10( 4), 1- 8. (in Chinese)
Chen Z. M., W. B. Min, 1999: Statistical study on activity of southwest vortex. Advances in Theoretical Research on the Second Atmosphere Scientific Experiments over the Qinghai-Xizang Plateau II. Tao et al., Eds., China Meteorological Press, Beijing, 368- 378. (in Chinese)
Chen Z. M., M. L. Xu, W. B. Min, and Q. Miao, 2003: Relationship between abnormal activities of southwest vortex and heavy rain the upper reach of Yangtze River during summer of 1998. Plateau Meteorology, 22, 162- 167. (in Chinese)
Chen Z. M., W. B. Min, and C. G. Cui, 2007c: Diagnostic analysis on the formation and development of meso-scale vortex systems. Torrential Rain and Disasters, 26, 29- 34. (in Chinese)e898726f-42a9-4172-8863-4f3565b3fe81mag12249200726425f42694a983f084707f5403fbc4deba06http://en.cnki.com.cn/Article_en/CJFDTOTAL-HBQX200701006.htmhttp://en.cnki.com.cn/Article_en/CJFDTOTAL-HBQX200701006.htmBased on analysis and statistics of the 1959-1990 data,it is shown that the situation feature in median-low layer in troposphere plays an important role in flood-causing heavy rain in Jiangxi.The effect of each k
Gao S. T., 1987: The dynamic action of the disposition of the fluid field and the topography on the formation of the southwest vortex. Chinese J. Atmos. Sci., 11, 263-271. (in Chinese)851fa13e-df95-47d4-b790-4aa36f5c49d89b472efebeb806df1198e6dd89f1aec4http://en.cnki.com.cn/Article_en/CJFDTOTAL-DQXK198703004.htmhttp://en.cnki.com.cn/Article_en/CJFDTOTAL-DQXK198703004.htmIn this paper, two-layer models are adopted in considering the dynamic action of the disposition relation between upper layer and lower layer fluid fields on the formation of the south-west vortex. It is known that the formation of the south-west vortex is a kind of stationary state related to a basin or a valley and the disconnected layer current over it. If the west winds of upper and lower layers are disconnected, the shallow warm and moist air of lower layer is favorable to the formation of the south-west vortex. If there exist the disconnected layers between the upper east wind and the lower west wind, the shallow east wind of upper layer is favorable to the formation of the south-west vortex. The smaller protruding hills are useless in forming the south-west vortex.
He G. B., W. L. Gao, and N. N. Tu, 2009: The dynamic diagnosis on easterwards moving characteristics and developing mechanism of two Tibetan Plateau vortex processes. Acta Meteorologica Sinica, 67, 599- 612. (in Chinese)10.11676/qxxb2009.06007871dd5-334e-455d-a585-ae601a792630558420094876988fdff79d83cca6fae14bab77b2b1http%3A%2F%2Fen.cnki.com.cn%2FArticle_en%2FCJFDTOTAL-QXXB200904010.htmhttp://en.cnki.com.cn/Article_en/CJFDTOTAL-QXXB200904010.htmBy using NCEP reanalysis data, calculating physical variables， and combining application of observatory data, satellite data and radiosonde data, the characteristics and development mechanism of two Tibetan Plateau vortex processes which happened during 19-22 July 2008 (“7.21” process) and 29 July to 1 August 2007 (“7.31” process) are analyzed dynamically. The results show that the positive vorticity moving eastwards is obvious along with the plateau vortex moving eastwards. If the plateau vortex is sequentially enhanced after it moves out of the Plateau, it behaves as follows: deep positive vorticity accompanies with the deep air vertical up movement as well as accompanies with strong convergence in middle and low troposphere levels before the plateau vortex moves out of the plateau. The positive vorticity is strengthened with the stronger air vertical up movement and stronger convergence in middle and low troposphere levels and stronger divergence in middle and upper troposphere levels after the plateau vortex moves out of the plateau. If the plateau vortex is sequentially weakened after moves out of the plateau, it behaves as follows: positive vorticity is weaker and accompanies with the weaker deep air vertical up-movement, accompanies with less convergence in middle and low troposphere levels before the plateau vortex moves out of the plateau. The positive vorticity is weakened with the weaker air vertical up movement and less convergence whole troposphere after the plateau vortex moves out of the plateau. When the plateau vortex moving over the plateau, the area of positive vorticity change rate center almost agrees with the area of positive vorticity center. The positive vorticity area maintenance, development and weakening dynamic mechanism which is close related with the development of the plateau vortex are mainly controlled by the total vorticity source's generation, development, and weakening. The maintenance and development of convergence or divergence fields have important influence on total vorticity source and take an important role in the maintenance and development of low vortex. The dynamic influence of topography makes the plateau vortex easier to develop on lee slope side of the big topography. The nearby and north area leaning north direction winds is favorable to the development of the plateau vortex. The vertical vorticity transition is not favorable to the strengthening of plateau vortex in the middle and low troposphere levels. The results also show that stream field convergence is stronger, the movements of cold and warm air are more active and the congregation of instability energy is more obvious during “7.21” process than during “7.31” process. The release of instability energy triggered by cold air is an important mechanism of low vortex development. That the meeting of cold and warm air leads to the maintaining and strengthening of convergence stream fields is the important factor of maintaining and strengthening of low vortex.
Institute of Plateau Meteorology, China Meteorological Administration, Chengdu, Plateau Meteorology Committee of Chinese Meteorological Society, 2013: Southwest Vortex Yearbook in 2012. China Science Press, Beijing, 352 pp. (in Chinese)
Kuo Y. H., L. S. Cheng, and J. W. Bao, 1988: Numerical simulation of the 1981 Sichuan flood. Part l: Evolution of a mesoscale southwest vortex. Mon. Wea. Rev., 116, 2481- 2504.10.1175/1520-0493(1988)116<2481:NSOTSF>2.0.CO;29d3db362-c7b5-4e65-a70e-59b380bf6d9b2978e8c1ab545c601387282feb344e4ehttp://www.researchgate.net/publication/260495494_Numerical_Simulation_of_the_1981_Sichuan_Flood._Part_I_Evolution_of_a_Mesoscale_Southwest_Vortexhttp://www.researchgate.net/publication/260495494_Numerical_Simulation_of_the_1981_Sichuan_Flood._Part_I_Evolution_of_a_Mesoscale_Southwest_VortexAbstract During the period 11鈥15 July 1981, heavy rainfall occurred over the Sichuan Basin in China, resulting in severe floods that took a large toll in human life and property damage. Mesoscale analyses by Kuo, Cheng and Anthes have shown that the flood was directly related to the development of a long-lived mesoscale southwest (SW) vortex over the basin. In this paper we present the results of numerical experiments aimed at 1) testing the capability of a limited-area mesoscale model to predict the evolution of the SW vortex and the accompanying heavy precipitation, 2) examining the structure of the simulated vortex using the model data, and 3) elucidating the role of various physical processes in the evolution of the SW vortex. Principal findings are: 1) The control experiment, which utilized an 80-km grid spacing and simple physical parameterizations, was able to simulate the evolution of the mesoscale SW vortex and the accompanying heavy precipitation. The simulation captured many observed features as analyzed by Kuo, Cheng and Anthes. The SW vortex formed completely within the southwesterly monsoon current, remote from the baroclinic frontal system to the north. At its mature stage, the SW vortex possessed a column of cyclonic vorticity, extending from the surface to 250 mb with very little vertical tilt. The core of the vortex was characterized by strong vertical motion, a considerably higher e compared with its environment. The horizontal momentum was uniformly distributed within the vortex layer. The vorticity field and the vertical motion field were in phase, which was favorable for the development and the persistence of the SW vortex. The model predicted a maximum 48-h precipitation (ending at 0000 UTC 14 July) of 213 mm over the Sichuan basin, which compared favorably with the observed precipitation. 2) Latent heat release was essential for the development of the SW vortex and the resulting precipitation. A simulation without latent heating produced a much weaker SW vortex and little vertical motion. The total 48-h precipitation was only 35 mm, an order of magnitude less than that of the control simulation. The results suggest a strong interaction between cumulus convection and the SW vortex. 3) Surface sensible and latent heat fluxes were important to the precipitation forecast. An experiment with surface energy fluxes removed predicted a maximum 48-h rainfall of 70 mm, one-third of the value of the control simulation. The Intensity of the SW vortex was weakened as a result of decreased latent heat release. 4) Further sensitivity experiments showed that the SW vortex observed in this case was a terrain-induced standing eddy. Its formation was not influenced by diabatic processes (e.g., latent heating and surface energy fluxes), although these processes were important for its development. 5) The differential frictional effect, hypothesized over the past decade to be a plausible mechanism for the formation of the SW vortex, was shown to be unimportant in this case. The surface friction acted as both a vorticity sink and an energy sink. When it was removed, the SW vortex evolved sooner with considerably stronger intensity. 6) A trajectory diagnosis and a model experiment with modified topography showed that as the southwesterly monsoon current impinged upon the mesoscale Yun-Gui Plateau, which extends from the southeastern corner of the main Tibetan Plateau, the low-level flow was blocked. The flow aloft then descended into the Sichuan Basin on the lee side of the mesoscale plateau, creating cyclonic relative vorticity over the basin by stretching of earth's background vorticity. This explains why the Sichuan Basin is a climatically favorable location for the origin of the SW vortex.
Li G. P., J. Wan, and J. H. Lu, 1991: A potential mechanism of the warm vortex genesis in southwest China. Quarterly Journal of Applied Meteorology, 2, 91- 99. (in Chinese)
Li G. P., X. P. Luo, T. Chen, and G. Chen, 2011: Preliminary theoretical study of waves in the Tibetan Plateau vortex. Plateau Meteorology, 30, 553- 558. (in Chinese) 86396ff3-7099-4a31-b472-da458937cd8dmag484262011303553907948fd29cce8b7a657bb5e05858246http%3A%2F%2Fen.cnki.com.cn%2FArticle_en%2FCJFDTOTAL-GYQX201103000.htmrefpaperuri:(e06118a561797e7382bb8941a4fe5b82)http://en.cnki.com.cn/Article_en/CJFDTOTAL-GYQX201103000.htm<FONT face=Verdana>The Tibetan Plateau Vortex (TPV) was assumed as vortices in boundary layer forced by diabatic heating in this article. On this basis, the dispersion relation and characteristics of various types of waves in TPV were deduced by working out and contrasting the linear model in orthogonal coordinate and in cylindrical coordinates, respectively, and comparison of results by those two models is given. In addition, the relationship between waves and characteristics of flow field of the vortex were also discussed. It is summarized that TPV may contain inertia-shallow gravity waves and vortex Rossby waves, this is very important to understand the TPV and its effects on the weather in the downstream of the Tibetan plateau.</FONT>
Lu J. H., 1986: An Introduction to Southwest China Vortex. China Meteorological Press, Beijing, 276 pp. (in Chinese)
Luo S. W., 1992: The Researches of Several Synoptic Systems of Tibetan Plateau and Nearby Areas. China Meteorological Press, Beijing, 205 pp. (in Chinese)
Qian Z. A., F. M. Shan, J. L. Nu, Y. X. Cai, and Y. C. Chen, 1984: The discuss on climate factors and statistic analysis of the Tibetan Plateau vortex in summer 1979. The Tibetan Plateau Meteorological Experiment Corpus II. Edit Group of Tibetan Plateau Meteorological Experiment Corpus, Eds., China Scientific Press, Beijing, 182- 194. (in Chinese)
Song W. W., G. P. Li, and Q. K. Tang, 2012: Numerical simulation of the effect of heating and water vapor on two cases of Plateau vortex. Chinese J. Atmos. Sci., 36, 117- 129. (in Chinese)10.1007/s11783-011-0280-zbe7ff34d-fcfc-4e1a-82be-68418cdeb1c9a10a9124c6a9420484981b75b71a0c04http%3A%2F%2Fen.cnki.com.cn%2FArticle_en%2FCJFDTOTAL-DQXK201201010.htmhttp://en.cnki.com.cn/Article_en/CJFDTOTAL-DQXK201201010.htmBy using the satellite Temperature of Brightness Blackbody(TBB) data,NCEP 1 reanalysis data,and nonhydrostatic mesoscale numerical model MM5,control experiment and six sensitivity experiments which are adiabatic,no surface sensible heating,double surface sensible heating,no evaporation effect,no latent heat of condensation,and no water vapor,are performed for two cases of plateau vortex occurring during 28-29 July 2005 and 29-31 July 2009,and the happening,development,and structure change of the plateau vortex during 28-29 July 2005 are mainly discussed.The results show that the vortex center and the vortex structure at 500 hPa simulated in the control experiment are the same as actuality.The adiabatic conditions affect the formation,development and structure change of the vortex most remarkably.The latent heat of condensation and the water vapor do not play decisive roles in formation of the vortex,but play key roles in vortex maintenance and structure characteristics evolvement.Surface latent heat has some effect on the development of the vortex,and no surface latent heat slightly decreases the strength of the vortex.The effect of surface sensible heat on the vortex is different for different cases,and depends on the developing stage of the vortex,and also that the developing stage is daytime or night.
Takahashi H., 2003: Observational study on the initial formation process of the Mei-yu frontal disturbance in the eastern foot of the Tibetan Plateau in middle-late June 1992. J. Meteor. Soc.Japan, 81, 1303- 1327.10.2151/jmsj.81.1303be9207d2-0dbb-4d80-ab53-410f1c518e18c6b91a2308837d6a9c877170bcb6136ahttp://ci.nii.ac.jp/naid/10013698361http://ci.nii.ac.jp/naid/10013698361In this research, a case study is conducted on the formation process of the Mei-yu frontal disturbance in the eastern foot of the Tibetan Plateau. The target period is middle-late June of 1992, during which the Mei-yu front is re-intensified after the decaying phase observed in middle June. The re-intensification process of the Mei-yu front occurs in accordance with the approach of the migrating upper level trough to the north of the Plateau. When the upper level trough is situated to the northwest or north of the Plateau, the lower level high pressure area becomes apparent. Subsequently, the low pressure area on the northeast of the Plateau deepens. At the same time, a shallow cold air mass observed below the 700 hPa level formed in the southeast of the low pressure area. The appearance of the cold air mass might be related to the development of low and high pressure systems to the north-northeast of the Plateau. Concurrently, a lower level strong westerly wind appears along the northern periphery of the Plateau, and turns into northwesterly or northerly wind along the eastern periphery of the Plateau. A shear line formed in the northeastern or eastern foot of the Plateau between this northwesterly wind and the southerly wind prevailing over the North-Middle China Plain. This shear line in the lower layer changed into the Mei-yu frontal disturbance after OUTC 21 June. Note that the wind system along the northern-eastern periphery of the Plateau mentioned above is considered to be an ageostrophic wind system, accompanied by the transient small scale low and high pressure systems that migrate clockwise along the northern-eastern periphery of the Plateau. The synchronic appearance of the cold air mass and the shear line is considered to be an effective trigger for the formation of the initial Mei-yu frontal disturbance. Further, the coupling of the upper level migrating trough and the lower level shear line also can be important for the evolution of the Mei-yu frontal disturbance.
Tao S. Y., Y. H. Ding, 1981: Observational evidence of the influence of the Qinghai-Xizang (Tibet) Plateau on the occurrence of heavy rain and severe convective storms in China. Bull. Amer. Meteor. Soc., 62, 23- 30.f44abb8a-d548-474e-b274-0ac4fc218581/s?wd=paperuri%3A%289e6d406adf4ccd08a3c3969f54ec774c%29&filter=sc_long_sign&sc_ks_para=q%3DObservational%20evidence%20of%20the%20influence%20of%20the%20Oinhiu-Xizang%20%28Tibet%29%20plateau%20on%20the%20occurrence%20of%20heavy%20rain%20and%20severe%20storms%20in&tn=SE_baiduxueshu_c1gjeupa&ie=utf-8
Wang B., 1987: The development mechanism for Tibetan Plateau warm vortices. J. Atmos. Sci., 44, 2978- 2994.acab1e0f-0db6-4061-bed7-7bf8094df7e8a58d44982f58767e471d6f747d3f8b0ehttp%3A%2F%2Fwww.researchgate.net%2Fpublication%2F249608976_The_Development_Mechanism_for_Tibetan_Plateau_Warm_Vorticesrefpaperuri:(3ad28aea529a970cf94cf10d2369f996)http://www.researchgate.net/publication/249608976_The_Development_Mechanism_for_Tibetan_Plateau_Warm_Vortices
Wang X., Y. Q. Li, S. H. Yu, and X. W. Jiang, 2009: Statistical study on the plateau low vortex activities. Plateau Meteorology, 28, 64- 71. (in Chinese) 8e82ed75-050b-4a12-8842-873457f321fbmag4842620092816488d78d4724357b37bc550b766f6a6abbhttp%3A%2F%2Fen.cnki.com.cn%2FArticle_en%2FCJFDTOTAL-GYQX200901008.htmrefpaperuri:(cc6cdae84690c5a7789dba8ad2acf041)http://en.cnki.com.cn/Article_en/CJFDTOTAL-GYQX200901008.htm<FONT face=Verdana>The activity characteristics of the Plateau Low Vortex (PLV) in summer(from May to September) are investigatedby using the daily synopticcharts of 500 hPa at 08:00 and 20:00 (BST) from 1980 to 2004. Some significant results areobtained as follows: The occurrence frequency of PLVs in summer has evident interdecadal, interannualand intraseasonal variation characteristics, and shows a decreasing tendency in the 1990s comparing with that in the 1980s. July is an active period of PLVs. The four sources of PLV forming in the Tibetan Plateau are between Shenzha and Gaize, northeastern Naqu, northeastern Dege, and Songpan. PLVs moving out of the Tibetan Plateau also have four sources: Northeastern Naqu, Qumalai, Dege and Maqin. Some PLVs can survive over 36 h in the Plateau and move eastward including three routes (northeast, southeast and east) that PLVs moving toward northeast are in the majority, but the routes out of the Plateau are different from those in the Plateau that most of PLVs are moving toward east first, then toward northeast and southeast. There are two main routes when PLVs are moving out of the Plateau, one is northeast to Hexi, Ningxia and Loess Plateau, the other is southeast to Sichuan Basin, and PLVs moving to Loess Plateauare the most. PLVs move out Plateau also has evident interannualand intraseasonal variation characteristics.Most of PLVs will weaken and vanish during 12 h after moving out of the Plateau, some can persist for 60 h, and only a few for 100 h, even 192 h. They would influence the precipitation in the vast area of east China, and maybe Korea peninsular and Japan. Warm PLVs are nearly two timesmore than baroclinic PLVs in the beginning state, while after moving out of the Plateau, the characteristics of PLVs change a lot during 12 h and most are baroclinic vortices. The occurring sources, removing routes and properties of PLVshave changed since the middle of 1980s compared with 1960s~1970s.</FONT>
Wang Z., K. Gao, 2003: Sensitivity Experiments of an eastward-moving southwest vortex to initial perturbations. Adv. Atmos. Sci., 20, 638- 649.10.1007/BF029155070622466b-f87a-41ae-bbff-3a63e86ffef38d9ac7b109d09d933c73f78344b1099bhttp%3A%2F%2Fen.cnki.com.cn%2FArticle_en%2FCJFDTOTAL-DQJZ200304014.htmrefpaperuri:(021bfca4e720cfdef2d7f47c7c3f9875)http://en.cnki.com.cn/Article_en/CJFDTOTAL-DQJZ200304014.htmWhether the initial conditions contain pronounced mesoscale signals is important to the simulation of the southwest vortex. An eastward-moving southwest vortex is simulated using the PSU/NCAR MM5. A modest degree of success is achieved, but the most serious failure is that the formation and displacement of the simulated vortex in its early phase are about fourteen hours later than the observed vortex. Considering the relatively sparse data on the mesoscale vortex and in an attempt to understand the cause of the forecast failure, an adjoint model is used to examine the sensitivity of the southwest vortex to perturbations of initial conditions. The adjoint sensitivity indicates how small perturbations of model variables at the initial time in the model domain can influence the vortex. A large sensitivity for zonal wind is located under 400 hPa, a large sensitivity for meridional wind is located under 500 hPa, a large sensitivity for temperature is located between 500 and 900 hPa, and almost all of the large sensitivity areas are located in the southwestern area. Based on the adjoint sensitivity results, perturbations are added to initial conditions to improve the simulation of the southwest vortex. The results show that the initial conditions with perturbations can successfully simulate the formation and displacement of the vortex; the wind perturbations added to the initial conditions appear to be a cyclone circulation under the middle level of the atmosphere in the southwestern area with an anticyclone circulation to its southwest; a water vapor perturbation added to initial conditions can strengthen the vortex and the speed of its displacement.
Ye D. Z., Y. X. Gao, 1979: Meteorology of The Tibetan Plateau. China Scientific Press, Beijing, 278 pp. (in Chinese)
Yu S. H., W. L. Gao, 2006: The observational facts analysis of vortex moving out of The Tibetan Plateau. Acta Meteorologica Sinica, 64, 392- 399. (in Chinese)
Yu S. H., W. L. Gao, and Y. H. Xiao, 2008: Analysis for the influence of cold air mass on two cases of plateau vortex moving out of the Tibetan plateau. Plateau Meteorology, 27, 96- 103. (in Chinese)10.3724/SP.J.1047.2008.00014eaccba7e-cea1-430b-98fc-e593c76d071da8167fc663ce06b39ccbe30f715728f1http%3A%2F%2Fen.cnki.com.cn%2FArticle_en%2FCJFDTOTAL-GYQX200801010.htmrefpaperuri:(572ed1f5f73cd536eccb9efeae5b006d)http://en.cnki.com.cn/Article_en/CJFDTOTAL-GYQX200801010.htmThrough the two cases of Plateau vortex moving out of the Plateau during 12~20 August 1998 and 12~14 July 2003,the baroclinic of vortex and temperature advection are studied.The results are as follows:(1) Tole Plateau vortex moved out of the Plateau mainly due to northeast lasting invasion of cold air flow and the Nomhon Plateau vortex moved out of the Plateau mainly due to northwest cold air invasion to the vortex area before the west wind trough.(2) Plateau vortex moves out of the Plateau when there is strong baroclinic condition above 600 hPa in vortex pole and also with strengthened baroclinic condition on 500 hPa in eddy area.But Tole Plateau vortex baroclinic condition in vortex pole and strengthened baroclinic condition on 500 hPa in eddy area are all weaker than the Nomhon Plateau vortex.Tole Plateau with north cold and south warm conditions is stronger than the Nomhon Plateau vortex.(3) Plateau vortex is mainly controlled by the cold air advection in the eddy area and moves out of the Plateau when the west cold air advection is stronger than the east;the enhancement of the cold flux in west area will accelerate the development of the Plateau vortexes and will be good to the lasting time of the Plateau vortexes to the east of the Plateau.By influence of the shear line,the moving out of the Plateau Tole votex west region strong cold air advection is weaker than the Nomhon vortex which is influenced by the west wind trough.And the cold air advection area of Tole vortex moving out of the Plateau is bigger than the Nomuhong vortex.
Yu S. H., W. L. Gao, 2009: Large-scale conditions of Tibet Plateau vortex departure. Sciences in Cold and Arid Regions, 1, 559- 569.c0841264-fbdb-463d-bfa8-a4d2bea5523db405dafe3a1f58189e977f6f196b5a53http%3A%2F%2Fd.wanfangdata.com.cn%2FPeriodical_hhqkx-e200906010.aspxrefpaperuri:(25bf3611c8507baa158b82c13c28cea7)http://d.wanfangdata.com.cn/Periodical_hhqkx-e200906010.aspxBased on the circumfluence situation of the out- and in-Tibet Plateau Vortex (TPV) from 1998-2004 and its weather-influencing system,multiple synthesized physical fields in the middle-upper troposphere of the out- and in-TPV are computationally analyzed by using re-analysis data from National Centers for Environmental Prediction and National Center for Atmospheric Research (NCEP/NCAR) of United States.Our research shows that the departure of TPV is caused by the mutual effects among the weather systems in Westerlies and in the subtropical area,within the middle and the upper troposphere.This paper describes the large-scale meteorological condition and the physics image of the departure of TPV,and the main differences among the large-scale conditions for all types of TPVs.This study could be used as the scientific basis for predicting the torrential rain and the floods caused by the TPV departure.
Yu S. H., W. L. Gao, J. Peng, and Y. H. Xiao, 2014: Observational facts of sustained departure Plateau vortexes. J. Meteor. Res., 28, 296- 307.10.1007/s13351-014-3023-9b9e2ba8a-d057-4bb6-b4d3-544f41eb4a26a2510b503efdbabb3f0cbfd381635852http%3A%2F%2Flink.springer.com%2F10.1007%2Fs13351-014-3023-9http://d.wanfangdata.com.cn/Periodical_qxxb-e201402009.aspxBy using the twice-daily atmospheric observation data from 1998 to 2012,station rainfall data,Tropical Rainfall Measure Mission(TRMM) data,as well as the plateau vortex and shear line year book,characteristics of the sustained departure plateau vortexes(SDPVs) are analyzed.Some new useful observational facts and understanding are obtained about the SDPV activities.The following results are obtained.(1)The active period of SDPVs is from June to August,most in July,unlike that of the unsustained departure plateau vortexes(UDPVs),which have same occurrence frequencies in the three summer months.(2)The SDPVs,generated mainly in the Qumalai neighborhood and situated in a sheared surrounding,move eastward or northeastward,while the UDPVs are mainly led by the upper-level trough,and move eastward or southeastward.(3) The SDPVs influence wide areas of China,even far to the Korean Peninsula,Japan,and Vietnam.(4) The SDPVs change their intensities and properties on the way to the east.Most of them become stronger and produce downpour or sustained regional rainstorms to the south of Yellow River.(5)The longer the SDPV sustains,the more baroclinity it has.(6) When an SDPV moves into the sea,its central pressure descends and rainfall increases in all probability.(7) An SDPV might spin over the bend of the Yellow River when there exists a tropical cyclone in the East China Sea.It could also move oppositely to a landed tropical low pressure originated from the sea to the east of Taiwan or from the South China Sea.
Zhang S. L., S. Y. Tao, Q. Y. Zhang, and X. L. Zhang, 2001: Meteorological and Hydrological characteristics of severe flooding in China during the summer of 1998. Quarterly Journal of Applied Meteorology, 12, 442- 457. (in Chinese)99f69639-f6e5-43c6-ae16-7a5dea26057e599c0be0cacb55de8d5b3342c12c8fbfhttp://en.cnki.com.cn/Article_en/CJFDTOTAL-YYQX200104006.htmhttp://en.cnki.com.cn/Article_en/CJFDTOTAL-YYQX200104006.htmAn extremely great flood occurred over the Yangtze River, Nenjiang-Songhuaji ang regions, and Pearl River during the summer of 1998, its meteorological and h ydrological characteristics and causes are presented. Pearl River, Yangtze Riv er, Nenjiang-Songhuajiang basins had successive heavy rains in the second half o f June. Yangtze River valley experienced the second period of the Meiyu in the l ast ten-day period of July. Heavy rainfalls centered in Zhalantun were observed over Nenjiang-Songhuajiang regions in first half of August. Frequent heavy rai n falls brought about the rapidly rising water level in most part along the middle reaches of Yangtze, Nenjiang, and Pearl River, and led to the greatest floods in the recent 100 years. The southward shifted subtropical high over the West Paci fic was responsible for the second period of Meiyu. The right mixture of subtrop ical high, monsoon swell from South China Sea, cold air mass coming from mid-hi g h latitudes, and MCSs from the Tibetan Plateau contributed to successive heavy r ains over the Yangtze River valley.
Zhou G. B., T. L. Shen, and Y. Han, 2006: A numerical simulation and diagnoses case analysis of typhoon affect on southwest vortex. Scientia Meteorologica Sinica, 26, 620- 626. (in Chinese)10.1016/S1872-2032(06)60022-Xc37628d9-404c-46a4-94e0-b6df32b77fcaaef9d2532079e66bdd00788ca92917adhttp%3A%2F%2Fen.cnki.com.cn%2FArticle_en%2FCJFDTotal-QXKX200606004.htmhttp://en.cnki.com.cn/Article_en/CJFDTotal-QXKX200606004.htmBy use of the NCEP data and MM5 model we simulate the southwest vortex,which caused the heavy rainfall in Sichuan and Chongqing during September 3 6,2004.The results show that the moving speed of the southwest vortex became slow,and its intensity was enhanced,and its life time extended because the southwest vortex was obstructed by the Sangda typhoon within the heavy rainfall weather process.The warm and damp airflow outside of the Sangda typhoon with a great deal of water vapour began to converge and water vapour began to accumulate rapidly when the northeast airflow,which was blew into the inland,turned to southwest airflow in the southeast of southwest vortex.And then,it induced the heavy rainfall nearby the southwest vortex.