Threshold Analysis of Sounding Physical Quantities of Rainstorm in Southwest China

Using physical quantities calculated by 16 radiosonde stations of Southwest China during 2010-2015,nine kinds of physical quantities with certain representational significance in water vapor,thermal and dynamic conditions were selected.Via box-plot,statistical analysis was conducted,and thresholds of sounding physical quantities of rainstorm in Southwest China were obtained,which could provide certain reference for further improving the rainstorm forecast in Southwest China.

Application of the Physical Quantity Field Evolution under Numerical Model in Precipitation Forecast of Yantai

[Objective] The research aimed to understand role of the forecast data about physical quantity field in precipitation forecast.[Method] By contrasting forecast and actual situation of the precipitation in Yantai during 2-3 July and 12-15 September,2011,advantages and disadvantages of the different numerical forecast models (Japan fax chart,European center,MM5,Grapes and T639) were analyzed.[Result] MICAPS system could provide live situation of the physical quantity field,but couldn't provide the future evolution situation.Japan fax chart,European center,MM5,Grapes and T639 could provide future evolution situation of the physical quantity field.[Conclusion] The contrasts and analyses on forecast situations of the physical quantity fields in many precipitation processes showed that evolutions of the vertical velocity,temperature dew point difference,relative humidity and wind field at the different heights could improve forecast accuracy of the precipitation in Yantai.

Comparative Analysis on Physical Quantity Diagnosis and Wind Profile Radar Data of Two Heavy Rainfalls

[ Objective] The research aimed to contrast physical quantity diagnosis and wind profile radar data of two heavy rainfalls. [ Method ] From circulation background, physical quantity field and wind profile radar data, we analyzed two big rainstorm weather processes （8 -9 July and August 10） in Lianyungang City in 2012. [ Result] Rainstorm generation was related to favorable large-scale circulation situation. The first-stage precipitation during 8 -9 July was warm-zone precipitation, and the precipitation at the second stage was triggered by shear line. Precipitation on August 10 was generated by typhoon low-pressure inverted trough and cold air. Sufficient water vapor content and strong water vapor transportation were favorable for generation of the heavy precipitation. Suction effect by divergence at high layer and convergence at middle and low layers was favorable for maintenance of the strong ascending motion. Occurrence of the heavy precipitation must have ascending motion condition. But it was not that the stronger the ascending motion, the stronger the rainfall intensity. Kindex and θse500 -θse 850 were closely related to rainstorm occurrence. Horizontal wind data of the wind profile radar provided fine structure of the atmospheric horizontal motion at vertical direction, could clearly display vertical structure of the wind field in rainstorm process, and directly reflected change characteristics of the wind field in precipitation process. [ Conclusion] The research could provide reference for future forecast work.

医学科技期刊物理量(physical quantity)与缩写

用于定量地扫描物理现象的量.即科学技术领域里使用的表示长度、质量、时间、电流、热力学温度、物质的量和发光强度的量。使用的单位应是法定计量单位。两分钟→2min,一秒钟→1 s,三小时→3h,4天→4d,1国际单位用IU。国际代号不用于无数字的文句中,如每天不能用每d,但每天10mg应写为10mg/d,次/秒→次/s。

Causes of a Heavy Snowfall Process in Eastern Yunnan in 2022

Based on NCEP/NCAR reanalysis data, Micaps data and ground observation data, the physical characteristics of a heavy snowfall process in eastern Yunnan from January 31 to February 3, 2022 were analyzed. The results show that the circulation background of the heavy snowfall process was "north-ridge and south-trough" type, and the cold air accumulated in the deep East Asian transverse trough. The cold advection behind the trough moved southwards into eastern Yunnan under the movement of the transverse trough. The establishment of upper and lower air jet provided abundant water vapor, and the snowfall area coincided with the strong water vapor convergence area. The strong cold center near the ground was maintained, and the cold air moved southwards. As a result, the cold pad was lasting and deep, and the ground temperature was 0 ℃ or below, which was conducive to snow accumulation on the ground. Seen from the spatial distribution of pseudo-equivalent potential temperature, the low layer always had certain warm and wet conditions during the heavy snowfall, which was conducive to the establishment of unstable energy. The snowfall occurred near the θ se steep area and the warm and wet unstable area. The vertical distribution of temperature had a good indication of precipitation form. The upper layer was controlled by strong cold advection, while the middle and lower troposphere was controlled by warm advection, and there was a warm inversion layer, which was conducive to the transformation of ice crystals into snowflakes, so that ice crystals fell to the ground in the form of snowflakes.

Analysis of Causes of “7.21” Rainstorm in Zhongwei City

Conventional information of Micaps, NCEP reanalysis data, and data from regional automatic weather stations were used to analyze the causes of rainstorm in southern mountains of Zhongwei City on July 21,2012. The results showed that the favorable circulation situation ＂ high in east and low in west＂ to rainfall in Nlngxia formed at 500 hPa before the precipitation appeared, and the heavy rainfall generated when cold air over Lake Baikal moved eastward and joined with warm and wet airflow on the northwest side of 584 line in Hetao region. Ground frontal surface and shear lines at 700 and 500 hPa were main influencing systems of heavy rainfall. Positive vorticity area at low levels, water vapor convergence, as- cending motion and stratification instability provided thermal, dynamic and energy conditions for the formation of the rainstorm. The rainstorm area was situated in wind direction convergence zone where southwest airflow changed into easterly airflow at 700 hPa. Sounding data show that temper- ature and humidity were high in the lower atmosphere which was nearly saturated, and atmospheric convection was unstable before the rainstorm appeared. After the rainstorm occurred, energy in the atmosphere released rapidly, and each index reduced fast, so that the precipitation ended.

Genetic Analysis of a Strong Convective Weather Process in Guannan County

To provide references for the forecast of strong convective weather process by county-level stations, through synoptic analysis, diagnostic analysis of physical quantities, analysis of satellite cloud pictures and new generation of weather radar data, the main reasons for the formation of strong convective weather process in Guannan County on May 16, 2012 was analysed based on the weather situation and physical quantities. The results show that this strong convective weather process occurred under conditions of inversion layer, upper dry and low-level wet climate, high- level convergence and low-level divergence, and unstable stratification, and surface cold front was the major factor triggering this strong convection. Besides, radar echo played an important role in the short-term impending forecast during the development of the weather. The occurrence of a strong convective weather is related to cold air activity, so we should strengthen the monitoring of cold air activity, so as to improve our waming lev- el and service capability to forecast strong convective weather.

Diagnosis and Analysis of a Rainstorm Process in Summer in Hami,Xinjiang

Based on conventional meteorological detection data and NCEP global reanalysis data,a rainstorm process in Hami,Xinjiang at the end of July 2018 was diagnosed and analyzed.The results show that this rare rainstorm occurred in the large-scale circulation situation of South Asia high,two ridges and one trough.The heavy precipitation area appeared on the right side of the southeasterly wind convergence area at 700 hPa,southerly flow at 500 hPa and the inlet area of southwest jet core at 200 hPa.The structure of high-level divergence and low-and middle-level convergence and strong vertical speed were important dynamic conditions for the occurrence and development of this rare rainstorm.The warm and moist air from the southern Sea of Japan and the Bay of Bengal was transported through different routes,providing a constant supply of water vapor and energy to the rainstorm area.Both EC and NCEP models have good predictive significance for this rainstorm,and the former is slightly better than the latter in terms of prediction effect.

RENEWAL OF BASIC LAWS AND PRINCIPLES FOR POLAR CONTINUUM THEORIES (X) -MASTER BALANCE LAW

Through a comparison between the expressions of master balance laws and the conservation laws derived by Noether＇s theorem, a unified master balance law and six physically possible balance equations for micropolar continuum mechanics are naturally deduced. Among them, by extending the well-known conventional concept of energymomentum tensor, the rather general conservation laws and balance equations named after energy-momentum, energy-angular momentum and energy-energy are obtained. It is clear that the forms of the physical field quantities in the master balance law for the last three cases could not be assumed directly by perceiving through the intuition. Finally, some existing results are reduced immediately as special cases.

Temporal-spatial Distribution and Short-range Prediction Indicators of Hail Weather in East Central Haixi Prefecture of Qinghai Province

[ Objective] The study aimed to discuss the temporal-spatial distribution and short-range prediction indicators of hail weather in east central Haixi Prefecture of Qinghai Province. [Method] Using hail data of six stations in east central Haixi Prefecture from 1960 to 2010, the temporal and spatial distribution of hail weather was analyzed firstly. Afterwards, based on the high-altitude factual data of 30 case studies of hail during 2006 -2010, its high-altitude and ground weather situation and physical quantity field were studied to summarize short-term circulation pattern and shod- range prediction characteristics of hail weather. [ Result] In east central Haixi, hail appeared from April to September, and it was most frequently from May to August. Meanwhile, hail was frequent from 14：00 to 20：00. Among the six stations, hail was most frequent in Tianjun but least frequent in Wulan. Moreover, hail disaster mainly occurred in Wulan and Tianjun. In addition, there were three typos of circulation pattern of hail weather at 500 hPa. Hail mainly occurred under the effect of northwest airflow, and it had shortwave trough, cold center or trough, jet stream core or one of the three. Hail appeared frequently under the situation of upper-level divergence and low-level convergence, and abundant water vapor and water vapor flux convergence at low levels were important conditions for hailing. [ Conclusion] The research could provide scientific references for improving the accuracy of hail forecast.

Analysis on the Heavy Snow Weather Process in Benxi Area

[Objective] The aim was to study the formation and development of a heavy snow in Benxi area. [Method] Based on conventional meteorological data, the formation and development of a heavy snow in Benxi area from December 4th to 5th in 2009 were analyzed from the aspects of weather situation evolution and physical quantity field feature. [Result] The heavy snow was caused by upper trough and North China cyclone. In this process, there was upper level divergence and lower level convergence over Benxi area, and it was warm at low attitude and cold at high attitude; southwest jet at low attitude transported water vapor from Bohai Sea to eastern Liaoning, which provided good water vapor condition for snow, but it didn’t reach heavy snow due to inadequate ascending force. The development of Ural Mountains high ridge played an important role in the snow process and the strengthened high ridge moving northward was beneficial to the southward movement of cold air and deepening of upper trough. Analysis on physical quantity field could provide reference for predicting beginning and ending time and strength of heavy snow. [Conclusion] The study could provide basis for the forecast of heavy snow.

Analysis of a Rare Continuous Rainy Process in Midsummer

[Objective] The research aimed to analyze a rare low temperature and rainy weather process which happened in Anhui Province from July 22 to August 14,2009.[Method] Based on the data of conventional observation,NCEP analysis field and automatic station,a rare low temperature and rainy weather process which occurred in Anhui Province from July 22 to August 14,2009 was analyzed.The formation reason of continuous rainy process in midsummer was discussed.The circulation characteristics and influence systems of continuous rainy process were revealed.On the base,the influences of configuration of circulation fields and difference of physical quantity fields at high and low layers on range and intensity of precipitation were analyzed.[Result] According to the circulation situation and influence system,the continuous rainy process could be divided into four stages:July 22-24,from July 27 to August 1,August 4-8 and August 9-14.Moreover,it was respectively affected by northeast low vortex,cold and warm air,high-level low trough,typhoon and periphery of subtropical high at four stages.The maintenance of big specific humidity zone provided sufficient water vapor condition for the continuous rainy weather.The rainstorm appeared in dense zone of specific humidity line,where the specific humidity >13 g/kg in the humidity front zone.A temperature trough maintained at 850 hPa.The cold air which continued to diffuse and go south was main reason of the abnormally low temperature during the continuous rainy period.Moreover,it provided ascending motion condition for precipitation maintenance.[Conclusion] The research provided references for actual forecast of continuous rainy weather.

Diagnostic Analysis of a Snowfall Weather in Beijing,Tianjin and Hebei in 2010

[ Objective] The research aimed to analyze a local snowstorm weather process which happened in Beijing, Tianjin and Hebei during I - 4 January, 2010. [ Method] Based on routine meteorological observation data and NCEP/NCAR 2.5° ×2.5° grid data （four times every day）, a lo- cal snowstorm weather process which happened in Beijing, Tianjin and Hebei during 1 -4 January, 2010 was carried out diagnostic analysis by using composite analysis method. [Result] Circumfluence on the ground and strong cold advection in the rear of upper trough were the main weath- er system of the snowfall. The deep thick wet layer and strong water vapor convergence provided sufficient water vapor for snowfall. The divergence field of low-level convergence and high^level divergence, dynamic coupling effect of vorticity provided favorable dynamic condition upwardly for the occurrence of strong snowfall. The steep dense area of Oso, low temperature at the ground layer and inversion temperature at the high layer provided certain energy condition for the development of snowfall weather. [ Conclusion] The research provided theoretical basis for snowfall forecast in future.

SEPARATING COUPLED PHYSIC QUANTITY BYPOTENTIAL OPERATOR

In the present paper, using the method of separating coupled physic quantity bypotential operator, we derive two special minmum principles in coupled thermoelastodynamics.

The Influence of Typhoon Usagi on Shaoyang City

[Objective] The research aimed to study the influence of typhoon Usagi on Shaoyang in 2013. [Method] By using synoptic analysis, physical quantity diagnosis and Doppler radar, a rainstorm process caused by typhoon Usagi was analyzed. [ Result] Sufficient water vaper and strong ascending motion caused by high-altitude divergence were favorable conditions for rainstorm generation in Shaoyang. Uplifting effect of the terrain in Shaoyang was also one of favorable conditions for rainstorm generation in Shaoyang. [Conclusion] The research could provide reference for flood prevention and disaster reduction in Shaoyang area.

Analysis of the Rainstorm Falling Zone in Guangxi during Influence Period of the 0906 Typhoon "Molave"

[ Objective] The research aimed to analyze rainstorm falling zone in Guangxi during influence period of the 0906 typhoon ＂ Molave＂. [ Method] For the heavy precipitation falling zone in southern and central parts of Guangxi after 0906 typhoon ＂ Molave＂ landed, 500 hPa circula- tion, physical quantity field, satellite cloud chart and terrain effect were analyzed. [ Result] 500 hPa subtropical high caused asymmetry of the ＂Me- lave＂ circulation, playing a key role for the strong precipitation falling zone in Guangxi. Physical quantity field analysis pointed out that after ＂ Me- lave＂ landed, water vapor convergence center was in southeast Guangxi, providing adequate moisture condition for the heavy precipitation in south- ern and central parts of Guangxi. The maximum positive vorticity center appeared at the middle and low layers in southern and central parts of Guangxi for a long time. At 200 hPa, there was a maximum divergence center. At 700 hPa, there was a maximum convergence center. High-level divergence and low-level convergence created conditions for heavy precipitation in the region. From satellite cloud chart, the heavy precipitation fall- ing zone related to asymmetric structure of the ~ Molave＂. In addition, uplifting effect of the terrain was conducive to occurrence of the large precipi- tation. [ Conclusion] The research provided reference for reduction and prevention of this kind of heavy precipitation.

Conventional Analysis on a Heavy or Torrential Rain Weather Process

[Objective] The research aimed to analyze a turning weather process in Binzhou City of Shandong Province in midsummer of 2010.[Method] Started from the short-term forecast ideas,the formation reason of heavy or torrential rain and local heavy rainstorm in Binzhou City during 4-5 August,2010 was analyzed from the circulation situation,physical quantity field,radar echo and so on.[Result] The westerly trough and cold air were the trigger mechanisms of precipitation.The warm wet air flow at the edge of subtropical high and the high-altitude low trough were the main systems of precipitation.It was the typical precipitation process that the northwest of subtropical high overlapped with the westerly trough.In the prior period,the high temperature continued.The cold air at 500 hPa made the convection strengthen.It was the main reason that the local precipitation was strong.In the forecast of rainstorm,the specific humidity,K index and SI index were the good physical quantities and reference indexes.In the formation process of rainstorm,K index had the increasing process.When the rainstorm finished,or the rain intensity weakened,K index decreased obviously.SI index indicated the development of convective precipitation.The radar echo analysis found that the mesocyclone appeared in the process for a short time.For it weakened quickly and disappeared in the shift process,the strong precipitation and gale were formed in the west of Binzou,but the hail wasn’t generated.[Conclusion] The research provided the experience for the forecast of such weather in future.

Analysis on a Cold Wave Weather Process in Winter in Gansu

[Objective]The research aimed to analyze a cold wave weather process in winter in Gansu.[Method] Based on routine observation data and numerical forecast products,formation reason and physical quantity characteristics of a cold wave process during 2-5 December,2008 were comprehensively analyzed by synoptic analysis and diagnostic analysis methods.[Result]The cold wave weather belonged to ' translot turning vertical type'.Collapse of the Urals ridge,turning vertical of the translot and strengthening south of the ground cold high induced the cold wave.Development of the Siberian low vortex drove the small branch of cold air in polar region supplementing south,playing certain promoting role in outbreak of the cold wave.Physical quantities in the cold wave process also had very good expression,such as vorticity,temperature advection,etc.[Conclusion]This research had important indication effect for early warning,forecast and decision service of the future similar weather process.

Characteristics of an Explosive Cyclone over Northeast China Revealed by Satellite Water Vapor Imagery

In this paper,an explosive cyclone(EC)that occurred over Northeast China in the spring of 2016 is studied by using 6.7μm FY satellite water vapor(WV)imagery and NCEP(1°×1°)reanalysis data.Moreover,the evolutions of the upper-level jet stream(ULJ),the vertical motions,and the potential vorticity(PV)are analyzed in detail.Results show that different shapes of the WV image dark zones could reflect different stages of the EC.At the pre-explosion stage,a small dark zone and an S-shaped baroclinic leaf cloud can be found on the WV imagery.Then the dark zone expands and the leaf cloud grows into a comma-shaped cloud at the explosively developing stage.At the post-explosion stage,the dark zone brightens,and the spiral cloud forms.The whole process can be well described by the WV imagery.The dynamic dry band associated with the sinking motion and the ULJ can develop into the dry intrusion later,which is an important signal in forecasting the EC and should be paid attention to when analyzing the WV imagery.Furthermore,the mechanism is also analyzed in detail in this article.EC usually occurs in the left-exit region of the 200-h Pa jet and the region ahead of the 500-h Pa trough where there is significant positive vorticity advection(PVA).When the EC moves onto the sea surface,the decreased friction would favour the development of the EC.The upper-level PVA,the strong convergence at low level,and the divergence at high levels can maintain the strong updraft.Meanwhile,the high PV zone from the upper levels extends downward,approaching the cyclone.Together,they keep the cyclone deepening continuously.

Analysis of the Process of Extreme Heavy Rainfall in the Cold Lake in Qinghai

[Objective] The aim was to analyze the process and reason of the extreme heavy rainfall on June 15,2011 in Cold Lake in Qinghai.[Method] The weather,physical field and satellite of one extreme heavy rain in the cold lake in Qinghai were expounded.[Result] The formation of the loop 'crooked neck' of high pressure,which on the one hand posed a typical situation in the circulation of heavy precipitation in Qinghai,and on the other hand,formed the southwest,southeast of the two water vapor transport in air,in addition to the small groove from the trough of Lake Balk hash and the split vortex plateau,resulted into the extreme heavy rainfall in Cold Lake.The presence of thermal low pressure 700 hPa was conducive to the accumulation of low energy and low-level moisture transport from the Qinghai region to the south of Qaidam Basin.[Conclusion] The resulting process was mainly due to heavy rain in the lower troposphere convergence,high-level divergence,high humidity areas and a strong vertical upward motion.