Assessing the Precipitation Enhancement Development Potential in 2013 Using the CWRPEP Method in Liaoning Province

Objective] The research aimed to assess the development potential of ar-tificial precipitation in Liaoning Province. [Method] The evaluation method of cloud water resource for precipitation enhancement potential was used. [Result] The annu-al total precipitation enhancement potential by cloud water resource in the air in 2013 was 1.23 bil ion tons in Liaoning, and cloud water resource for precipitation enhancement was 1.63 bil ion tons. [Conclusion] The spatial and temporal distribution for development potential of cloud water resource in the air was very uneven in Liaoning Province, and the mainly period was during spring and autumn. It wil be received obvious effect in the two seasons. In order to compensate for the restric-tion of the operational capability lack on cloud water resource development, we need to continue to improve the operation capacity building.

Shallow Analysis on the First Spring Soaking Rain Weather and Its Precipitation Enhancement Potential Forecast in Jinzhou Area in 2010

[Objective] The research aimed to study the first spring soaking rain weather and its precipitation enhancement potential forecast in Jinzhou area in 2010. [Method] From the weather situation characteristics, main influence system, forecast service, artificial precipitation enhancement operation and so on, the first spring soaking rain weather process in Jinzhou area in 2010 was summarized comprehensively. [Result] The weather situation characteristics of soaking rain were that the high-altitude cold air was weak, and the low-level warm wet airflow was obvious. The main influence systems were the high-altitude trough, the high-altitude shear line and the ground Mongolian cyclone. The ground inverted trough system advanced northward and got through with the same phase of Mongolian cyclone, which provided the certain energy and water vapor for the precipitation in Jinzhou area. It was one of key reasons for generating the soaking rain. The numerical forecast product played the certain guidance role in the forecast service work. The situation field forecast was accurate, but the precipitation forecast deviation was big. Therefore, the forecast service couldn’t depend on the numerical forecast product simply and totally, and should combine with the actual monitoring data to analyze and apply comprehensively. [Conclusion] The research played the safeguarding role in carrying out the large-scale artificial precipitation enhancement operation successfully in the whole area of Jinzhou.

Diagnostic Analysis of Potential Vorticity in a Heavy Precipitation Process in Qujing in September 2017

Based on the observation data from the automatic rainfall station and NCEP/NCAR reanalysis data,circulation analysis and diagnosis analysis of potential vorticity in a heavy rainfall process in September 2017 in Qujing were conducted.The results show that the heavy rainfall was mainly affected by the convergence zone between the two high pressures and shear line system,the precipitation area developed from the west to the southeast of Qujing,and the heavy rainfall area was concentrated in the central area.The southerly airflow in the middle and lower layers of the troposphere provided favorable water vapor conditions for heavy precipitation.The precipitation was characterized by high intensity,strong suddenness and small time scale.The heavy precipitation was concentrated from 04:00 to 06:00 on September 6.The high-and low-value centers of dry potential vorticity PV at 500 h Pa were indicative of the activities of cold and warm air in the process of heavy rainfall,and representative of the development of the convergence zone and the activities of shear line.That is to say,the high-value zone of dry potential vorticity PV at 500 h Pa was strengthened to penetrate into the center of Yunnan,leading the northerly airflow to the convergence zone.The deep southerly airflow in the relatively low-value zone of PV was uplifted to the north,converging the cold and warm air at the front of the convergence zone,resulting in heavy precipitation in Qujing.The high-value zone of wet potential vorticity MPV at 700 h Pa can also indicate the characteristics of unstable warm and humid air flow activity.MPV1<0,and MPV2>0,which easily caused the unstable energy release of wet convection and formed heavy precipitation.

A New Method in Determining Potential Region of Precipitation Enhancement Above Coastal Land

To ensure the effectiveness of the operation of artificial precipitation enhancement, a potential region for the operation should be determined in advance.As cloud microphysical measurements needed for the determination of the potential region of cloud seeding are not available before the operation of routine precipitation enhancement, a new method based on the growth process of ice crystal is put forward for determining the potential region using the numerical weather prediction model output.The ice supersaturation, accumulated water vapor within minus temperature layer (≥9 mm), and upward water vapor transportation are adopted as criteria to determine the potential time, height and region of cloud seeding, and the real-time radar images are applied to make decisions on the seeding commanding.The criteria and Doppler radar images are studied in a case of precipitation enhancement characterized by significant water vapor supply from the north part of a tropical cyclone in the northwest Pacific, which shows that the ocean plays a crucial role in the advection transportation of water vapor to the potential region of the coastal area.The study presents a new method to determine the potential region of precipitation enhancement using macro-physical quantities under ice crystal growth environment.The method possesses a clear physical significance and can be readily applied with the required and easily predicted parameters.

Analysis of the Potential of Precipitation Enhancement for Impounding Water in Reservoirs in Dabie Mountain Region

This paper studies the vapor pressure of water and precipitation situation in Lu'an Ground Station in Dabie Mountain area from 1979 to 1998.And the atmospheric perceivable water in Dabie Mountain can be calculated by virtue of the empirical formula for atmospheric perceivable water.Besides,by analyzing the data,the seasonal changes of perceivable water in Dabie Mountain and the efficiency of precipitation of each weather system is acquired.The results show that there is a great potential for precipitation enhancement in Dabie Mountain.This paper introduces the processes and operation forms of precipitation enhancement for impounding water in reservoirs in Dabie Mountain region.

Analysis of Precipitation Resource and Weather Modification Potential in Anyang

Using ground water vapor pressure and precipitation data at four times of one day during 1985- 2014 in each county（ city） of Anyang,precipitable water at each station was calculated,and temporal-spatial distribution of atmospheric maximum precipitable water and its change trend over the years in the city were analyzed. Results showed that atmospheric maximum precipitable water in Anyang City had the characteristics of summer far more than winter,autumn slightly higher than spring,west and south more,and east and north less,and presented the increasing trend year by year. We further analyzed the characteristic of monthly rainfall enhancement potential in each county,and mean in whole year was 80%. In spring and winter,rainfall enhancement potential in the west was bigger than east,while rainfall enhancement potential in the east was bigger than west in summer and autumn. The research provides reference basis for rationally carrying out artificial rainfall work,which could effectively ease uneven temporal-spatial distribution problem of water resource in Anyang City.

Analysis of a Heavy Precipitation Process Based on Wet Potential Vortex

In order to explore the relationship between heavy precipitation and the distribution characteristics of wet potential vorticity field,based on the NCEP 1°×1°6-hour reanalysis data,the wet potential vortex field in a heavy precipitation weather process in the central-southern part of Inner Mongolia was analyzed through the analysis of weather situation and calculation of vertical component(MPV_(1))and horizontal component(MPV_(2))of wet potential vortex(MPV).The results show that this heavy precipitation was a heavy precipitation weather process under the combined action of the cold air behind the trough and the southwest warm and humid airflow.The diagnostic analysis of θ_(se) shows that the south side of the area where the cold and warm air met before the precipitation was a high-temperature and high-humidity area,where a large amount of unstable energy was gathered,and the heavy precipitation occurred in the area with the most dense θ_(se) lines.This heavy precipitation process was dominated by the release of convective unstable energy in the lower troposphere,the positive pressure term of wet potential vortex MPV 1 was smaller than 0 in the lower troposphere and larger than 0 in the middle and upper layers;the positive-value wet potential vortex was transported to the lower layer,which was conducive to the release of unstable energy,so that precipitation increased.The negative-value center of wet potential vortex in the middle and low layers corresponded well to the heavy precipitation area,and the precipitation intensity and duration were consistent with the increase and enhancement time of the negative-value area of MPV_(1).The positive-value area of MPV_(1) was 6-12 h earlier than the heavy precipitation area,which has good indication significance for the prediction of the heavy precipitation area.In the lower troposphere,the configuration of MPV_(1)<0 and MPV_(2)>0 can be used as the basis for judging the location of precipitation center.

Effect of deformation temperature on precipitation, microstructural evolution, mechanical and corrosion behavior of 6082 Al alloy

The influence of cryorolling(CR),room temperature rolling(RTR)and post annealing on precipitation,microstructuralevolution(recovery,recrystallisation and grain growth),mechanical and corrosion behavior,was investigated in the present work.The precipitation kinetics and microstructural morphology of CR,RTR,and post annealed samples were investigated by differentialscanning calorimetry(DSC),transmission electron microscopy(TEM),and electron back scattered diffraction(EBSD)to elucidatethe observed mechanical properties.After annealing at200°C,UTS and hardness of CR samples(345MPa and HV127)wereimproved as compared to RTR samples(320MPa and HV115).The increase in hardness and UTS of CR samples after annealing at200°C was due to precipitation ofβ''from Al matrix,which imparted higher Zener drag effect as compared to RTR samples.Theimprovement in corrosion and pitting potentials was observed for CR samples(?1.321V and?700mV)as compared to RTRsamples(?1.335V and?710mV).In CR samples,heavy dislocation density and dissolution of Mg4Al3Si4-precipitates in the Almatrix have improved corrosion resistance of the alloy through formation of protective passive layer and suppression of galvanic cell,respectively.

Precipitation efficiency and its relationship to physical factors

The precipitation efficiency and its relationship to physical factors are examined by analyzing a two-dimensional cloud-resolving model simulation during TOGA COARE in this study. The basic physical factors include convective avail- able potential energy, water-vapor convergence, vertical wind shear, cloud ratio, sea surface temperature, air temperature, and precipitable water. Precipitation efficiencies do not show a close relationship to air temperature nor to sea surface tem- perature nor to precipitable water. The precipitation efficiency increases as the water-vapor convergence rate increases and vertical wind shear weakens, whereas it decreases as the convective available potential energy dissipates and anvil clouds develop.

AN EAST ASIAN SUBTROPICAL SUMMER MONSOON INDEX DEFINED BY MOIST POTENTIAL VORTICITY

Based on consideration of both thermodynamic and kinetic features of the subtropical summer monsoon in East Asia,a new index is defined by the moist potential vorticity (MPV) for this monsoon.Variation features of the subtropical summer monsoon over 60 years are analyzed using National Centers for Environmental Prediction/National Center for Atmospheric Research (USA) data from 1948 to 2007.Results show that the new index can well reflect the seasonal,interannual,and interdecadal variations of the East Asian subtropical summer monsoon.Correlation analysis of the new index and precipitation data from 160 stations in China shows that in high-index years,the summer monsoon is strong,and more rain falls in eastern North China,southwestern China,and along the coast of South China and less rain falls in the Yangtze-Huaihe R.basin.In low-index years,the opposite occurs.Lastly,the new index is compared with four established monsoon indices.The new index is found to have an advantage in representing summer rainfall in the Yangtze-Huaihe R.basin.

A STUDY ON BUFFERING CAPACITY OF THE FOREST SOIL AGAINST ACIDIC PRECIPITATION IN SEVERAL AREAS OF CHINA

Soil samples from several forest areas in China were analyzed by X-ray powder diffractometry after mineral separation and enrichment. The density gradient separation method with sequential extraction by acetone-methylene iodide mixtures was applied for the separation of fine sand fraction of soil samples. The clay fraction (【 2μm) was separated from silt fraction of soil samples prior to examination. Mineral components in some fine sand and clay samples were compared, and their weathering potentiality and buffering capacity against acidic precipitation were discussed.

Numerical Simulation and Moist Potential Vorticity Analysis of Torrential Rain in Jiangxi Province during June 2010

Based on the conventional ground observational data,a numerical simulation and moist potential vorticity( MPV) analysis has been carried on heavy rainfall event over Jiangxi province from 19 June to 20 June 2010,with a meso-scale rainstorm model. The results show that this rare rainstorm is a typical heavy rainfall over Meiyu front. The cold air flow behind North China vortex joined up the southwestern flow located in the northwest part of the strong and stable subtropical high,thus the cold air and warm air converged and maintained over the northern part of Hunan and Jiangxi province. The simulated precipitation of the high resolution model is very similar to the observational rainfall. The model has a good predictive skill for the location,intensity and center of heavy rainfall. By moist potential vorticity analysis,it is found that the distribution characteristic of MPV which heavy rainfall happens ahead has an obvious indication for precipitation forecast. The vertical overlapping of the positive and negative MPV1 areas is favorable to the generation and development of rainstorm. This zone is also the conjoint area of convective instability and baroclinic instability.

Reinvestigation of potential deformation during a heavy rainfall event in North China

In this study,the physical meaning and generation mechanism of potential deformation(PD)are reinvestigated.A main trait of PD is that it contains deformation,which is an important factor to precipitation but not well applied in precipitation diagnosis.This paper shows PD shares similar features to deformation,but contains much more physical information than deformation.It can be understood as a type of deformation of a thermodynamic-coupled vector(u*,v*).For convenient application,squared PD(SPD)is used instead for analysis.By deriving the tendency equation of SPD,it is found that whether SPD is produced or reduced in the atmosphere is associated with the angle between the dilatation axes of PD and geostrophic PD.When the angle is less thanπ2,SPD is generated.The diagnostic results during a heavy rainfall event in North China on 20 July 2016 show that the process of rapid increase in precipitation can be well revealed by SPD.The distribution of SPD becomes more organized and concentrated with increasing precipitation intensity.A diagnostic analysis of the SPD tendency equation shows that concentrated SPD is associated with the generation of SPD in the boundary layer followed by upward transport of the SPD.The concentration of SPD indicates a confluence of precipitation-favorable factors—namely,vertical wind shear and moist baroclinity,which can enhance vertical motions and thus cause an increase in precipitation.These diagnostic results further verify PD as a useful physical parameter for heavy precipitation diagnosis.

基于降维机理模型的储能电池安全充电在线控制技术

大倍率充电会引起储能电池负极析锂,进一步可能会诱发电池热失控并导致安全事故。而析锂副反应与电池负极电位直接相关,通过模型精确预测负极电位,传输至储能电池管理系统调整充电工况,可以有效抑制负极析锂。因此,文中提出一种基于降维机理简化伪二维(simplified pseudo two-dimensional,SP2D)模型的储能电池安全充电在线控制技术。首先,对伪二维(pseudo two-dimensional,P2D)模型中部分偏微分方程进行降维简化,建立SP2D模型,同时采用不同的方法获取相应的模型参数。其次,使用实验数据的端电压和负极电位对模型进行验证,结果表明模型在不同倍率恒流工况下精度较高。再次,基于SP2D模型结合比例控制器开展电池无析锂安全充电的仿真工作,结果表明,电池经过1895 s充电即达到截止电压4.3 V,且充电过程中负极电位均处于无析锂安全电位区间。最后,对仿真得到的充电策略进行循环和拆解验证,结果表明提出的充电方法能够实现电池无析锂安全充电。

西南地区一次典型冰冻雨雪复合极端灾害天气事件的环流特征及降水相态差异分析

在全球变暖气候背景下,复合型极端灾害天气事件频发。2008年以来我国南方冬季频发的雨雪冰冻,就是一种典型的复合型致灾极端天气事件。因此,本研究分析了西南地区一次典型大雪冻雨复合天气事件的大雪与冻雨期环流特征及降水相态差异,揭示了二者的关联特征。冻雨发生在贵州境内的云贵准静止锋锋面强斜压环境中,降雪主要发生在四川北部,位于静止锋以北的冷区。降雪区和冻雨区的垂直环流存在显著差异:降雪区以上升运动为主,温度基本随高度递减;冻雨区大气中低层存在逆温层,导致温度层结出现冷—暖—冷的分布,垂直运动呈两层环流模态,低层的上升运动受到中层下沉运动抑制,强上升运动不易发展。借助可综合表征环流特征和水汽相变的广义湿位涡理论,分别诊断大雪和冻雨发生发展时期的广义湿位涡分布特点,发现其斜压项的异常能更好体现准静止锋附近的大气斜压性,也可指示出大雪冻雨降水的落区及变化,可作为大雪冻雨区的动力识别特征量之一。通过气压扰动方程的计算分析,表明向下的扰动气压梯度力与浮力的平衡差异,是降雪与冻雨垂直环流特征差异的主要原因。本研究从环流特征入手开展雨雪冰冻复合极端灾害天气分析,可为复合降水相态预报和发电企业电力运行保障提供参考。

基于参比电极的析锂电池安全充电控制

电池系统是支撑下一代新型电网的关键,然而不合理的充放电策略会使电池发生析锂副反应,导致电池充放电性能大幅减弱。因此,文中针对三元锂离子电池,基于参比电极揭示了析锂后电池的充电性能变化情况,并对其安全充电电流进行控制。首先,设计不同温度下的充放电循环实验,得到低温循环与高温循环后的电池;其次,通过植入参比电极标定安全充电曲线对比电池的负极电位,发现高温循环后的电池发生了析锂,且平均充电电流相比新电池降低了61.7%;最后,对析锂后的电池建立安全充电荷电状态-温度-电流等高线图,对比新电池等高线图后发现,200 A以上的充电电流区域减少了69.84%。文中提供了一个析锂后电池充电性能衰减的量化指标,需要在实际的锂离子电池全寿命周期管理中予以考虑。

秋台风“梅花”造成浙江极端降水成因分析

利用全球降水观测计划卫星降水率产品、地面加密自动站和ERA5再分析资料,对202212号台风“梅花”造成浙江极端降水的成因进行分析。结果表明:台风“梅花”造成的极端降水主要分布在沿海和四明山区,极值在四明山区,9月12—13日强降水由台风北侧外围雨带造成,14日则主要为台风本体降水;高层西南风急流的稳定以及台风“梅花”在移动过程中与西风槽结合有利于维持台风强度并引起台风动力结构不对称;台风“梅花”与副热带高压间的东风是台风发展的主要水汽来源,西太平洋上热带气旋的存在也有利于台风“梅花”北侧水汽输送加强,导致台风强降雨带偏北;台风“梅花”北侧高层始终有位涡下传至对流层中低层,促使低层扰动中心的发展,冷空气侵入造成浙江东部中尺度斜压锋生;受四明山地形影响,台风“梅花”环流西北侧的偏北风进入内陆后形成中尺度辐合线,山前抬升,山后下沉,有利于山前降水增幅。

新安江水库流域降水时间演变特征

为了解新安江水库流域降水的长期演变特征,利用2006~2022年GPM降水数据、GLDAS土壤含水率数据和典型站点的降水量与水位数据,结合HYSPLIT、PSCF、CWT模式,分析了降水量和水位的时间演变特征、不同降水气团的差异和降水的潜在来源。结果表明,干流单一站点的降水量可用于代表新安江水库流域的降水量变化特征。降水量、0~200 cm土壤含水率和水位存在明显月际变化,降水量在6月最高,土壤含水率和水位在7月最高。2006~2022年新安江流域的降水气团共分为六类:1型西南内陆远距离气团(31.8%)、2型西北内陆气团(7.2%)、3型局地气团(19.7%)、4型西南内陆近距离气团(15.7%)、5型东部海洋气团(3.8%)和6型西部内陆气团(21.8%)。不同类型气团降水的时间分布特征存在显著差异。新安江流域降水的PSCF分布与CWT分布类似,高值区均位于其西南方向。新安江流域的降水潜在来源贡献主要是江西全省和湖南省的东部地区,在对其降水过程预报时应多关注该区域的降水气团变化。研究结果可为新安江水库防汛和水力发电提供理论依据。

老旧水厂平流池强化沉淀技术的开发及应用

平流沉淀池因其稳定的运行效果在我国水厂建设历程中被广泛应用。而部分老旧水厂因建设年代久远,普遍存在产水量低、出水浑浊度高、排泥含水率高、运行安全等级低等问题。又因其在现状供水系统中扮演的重要角色而又必须在用地紧张、原始资料不全、改造风险系数大的背景下进行挖潜改造,而目前国内主流的几种改造经验均具有明显的局限性,并不能普遍性地适用于所有老旧水厂平流池的技术改造。为了弥补国内相关研究和改造经验的空白,文章系统性地研究了平流池改造前后沉淀、排泥及集水等系列问题,开发出一种集末端强化沉淀、虹吸式排泥以及末端集水系统于一体的集成式改造工艺,以期解决老旧水厂平流池挖潜改造中遇到的技术难题。研究成果在南方某水厂实际投用后,当原水浑浊度为60~125 NTU时,出水浑浊度能够稳定在2.7 NTU以下,平均去除率在97.12%;出水COD_(Mn)平均值为1.48 mg/L;出水UV_(254)平均值为0.036 cm^(-1),处理效果优异。对比原沉淀池出水水质,改造后沉淀池的浑浊度去除效果提升70%~80%,产水率提高20%,达到了良好的运行目标,对国内平流池的改造具有一定的借鉴和示范意义。

分金液中金浓度对沉金工序的影响探讨

因某有色冶炼公司采用贵金属品位很低的进口铜精矿为原料,影响了后续铜阳极泥处理系统的贵金属回收。试验考察了终点电位和分金液金浓度对沉金工序的影响,得到较优的终点电位控制为270 mV,且将分金液返回分金工序进行氧化酸浸分金,每年可降低生产成本29.31万元。