山东滨州市冰雹天气分型和预报方法研究     

王培涛  王凤娇  张婷婷 《沙漠与绿洲气象(新疆气象)》2019,(3):33-40

利用山东滨州市7个国家气象站与61个人影作业站点观测资料,结合高空观测及探空、ECMWF再分析等资料,对2001—2011年滨州降雹时空分布特征、天气系统和物理量特征、降雹形势分型和预报方法进行研究。得出:(1)降雹日数年均8.6次,总体呈现明显下降的年际变化特征;4—10月可降雹,6—7月降雹最多;降雹主要出现在14时—翌日02时;北部沿海相对较多。(2)降雹形势主要有5种类型:冷涡型降雹、低槽型降雹、横槽型降雹、西北气流型降雹、其他小范围降雹。根据冷涡中心位置冷涡型划分为两个关键区;低槽型可分为前倾槽、阶梯槽、较深低槽、与中低纬度共同作用的槽;横槽型降雹范围广、破坏性大;西北气流型存在连续性。(3)4类13种物理量具有不同分布特征和变异系数,均具有较好的代表性。不同月份、不同降雹影响程度和影响系统,物理量具有较明显差别。(4)0℃层高度在1370~5331m时,7种物理量可用于预报冰雹,K≥17℃、T850-500≥25℃、LI≤2℃、SRH≥0.1m^2·s^-2、SSI≥240、SWEAT≥100、Cape≥2J·kg^-1时可能降雹。6月、7—8月和其它月分别有3种、1种、3种物理量指标组合可用于预报冰雹,物理量的组合和数值有差异。  相似文献   

登陆北上山东台风暴雨非对称分布的成因对比分析          下载免费PDF全文

孙兴池  吴炜  孙莎莎 《山东气象》2019,39(3):55-63

应用常规气象观测资料、NCEP 1°×1°再分析资料,选取登陆北上山东地点相近但暴雨落区分别位于台风中心西北侧和东北侧的两个台风,分析暴雨落区相对台风中心非对称分布的成因。结果表明：台风进入中纬度以后,0421号台风“海马”位于高空深槽前,与西风槽相互作用,西风槽携带的冷空气从西北侧侵入台风环流,产生湿斜压锋区强迫抬升、冷暖空气交绥、水汽辐合等因素造成暴雨,暴雨趋于出现在台风中心的西北侧,为高比湿舌前方、较强水汽辐合区与相当位温密集区叠加的区域;而0509号台风“麦莎”与副热带高压相互作用,引起涡度及涡度平流的非对称改变,暴雨区与500 hPa正涡度区或正涡度平流相对应,暴雨趋于出现在台风中心的东北侧,为强正涡度平流区与水汽辐合叠加的区域。  相似文献   

一次拖曳型飑线过程雨滴谱演变特征研究          下载免费PDF全文

王俊  刘畅 《山东气象》2019,39(2):43-57

利用Thies激光雨滴谱仪观测资料和CINRAD/SA多普勒雷达观测资料,分析了2017年7月18日一次典型中纬度拖曳型飑线过程不同发展阶段雨滴谱和积分参数的演变特征,主要结果为：1）成熟飑线回波包括对流带、过渡区和拖曳层状云区三部分,对流带前侧不断有对流带生成并合并到主对流带中,使得对流带的前沿具有强的反射率因子,并且有多个雨强大值中心。2）垂直穿过飑线对流带,雨强增加阶段有较少的小粒子（直径小于1 mm）和特大粒子（直径大于5 mm）,以及较低的雨滴浓度和反射率因子,而雨强减弱阶段有较多的小粒子和特大粒子,以及较高的雨滴浓度和反射率因子;飑线加强阶段,雨滴谱有较大的峰值直径（0.44 mm）、较多的大（直径大于3 mm）和特大粒子,而飑线减弱阶段,雨滴谱有较小的峰值直径（0.19 mm）、较少的大粒子。3）对流带、过渡区和层状云降水雨滴谱的Gamma谱三参数N0、μ、λ随雨强增大有明显的分层特征,相同雨强时,对流云和过渡区降水的三参数比层状云降水的数值大;而飑线不同发展阶段、不同降水类型的λ-μ关系具有一致性,二次多项式可以很好地拟合λ-μ关系。4）归一化雨滴谱参数NW和D0的分布可以用来区分对流云和层状云降水,并给出了新的分离线方程;另外,飑线在发展和减弱阶段的雨滴谱特征有明显差异,表明飑线演变过程降水形成的微物理机制发生变化,前期冷云过程有重要影响,而后期暖云过程起主导作用。  相似文献   

THE TEMPORAL AND SPATIAL DISTRIBUTION OF SEA SURFACE WIND ALONG THE COAST OF GUANGDONG PROVINCE IN CHINA     

廖菲  邓华  陈柏纬 《热带气象学报(英文版)》2019,25(1):129-140

Temporal and spatial distribution characteristics of sea surface wind in Guangdong''s coastal areas were analyzed with data from four offshore observational stations between 2012 and 2015. The results are shown as follows: (1) The probability distribution of wind speed was basically consistent with Gaussian distribution characteristics; winds of Beaufort force 6 or higher were observed mainly in far offshore stations from October to March. (2) The probability distribution of wind direction was represented well by Weibull distribution. The deviation of wind direction of far station was relatively small for it was mainly controlled by monsoon over the South China Sea, while the near offshore station had a relatively large diurnal variation because of the influence of local synoptic systems such as sea-land breeze. (3) There were significant seasonal differences in wind speed and direction observed by different offshore observational stations. In strong wind seasons, the deviation of wind direction was relatively small while the deviation of wind speed was relatively large, and vice versa. In contrast with Class I station, the other three stations exhibited approximately normal distribution of wind direction and wind speed deviations. (4) Wind direction diurnal variation was moderate in windy periods, while it was obvious in relatively lower speed conditions. The deviation of wind speed in windy periods was generally greater because it was influenced by mesoscale weather systems for 10-20 h, and the influence was complicated, resulting in greater local differences in wind speed.  相似文献   

中国银矿的资源特征及成矿规律概要   总被引：1，自引：0，他引：1  

张大权  江彪  王登红  王成辉  陈毓川  白鸽 《地质学报》2015,89(6):1008-1025

中国银矿资源丰富,成矿地质条件优越,主要以共伴生为主,近年来独立银矿找矿也取得一些进展。本文系统搜集了国内外银矿数量与规模、储量和分布等内容,梳理了中国银矿资源分布及储量分布规律,总结了中国银矿资源特点。在对全国490处银矿矿产地资料系统梳理的基础上,深入总结了中国银矿的成矿规律,划分了海相火山沉积型、陆相火山次火山岩型、矽卡岩型、热液型(脉型和层控型)、沉积变质型、沉积型和新生风化淋积型等7个银矿预测类型,其中前4个应该作为重点预测类型,并划分出32个成银带,编制了"中国成银带分布图",为中国银矿资源潜力评价和勘查部署提供了理论依据。  相似文献   

西藏大冈底斯北部金属矿床成矿系列研究   总被引：1，自引：0，他引：1  

罗梅  潘凤雏  李巨初  徐志忠  邓午忠  李关清  刘丽君 《地质学报》2015,89(4):715-730

依据近年西藏自治区矿产资源大调查的资料与西藏自治区矿产资源潜力评价研究获得的系统、详细的矿产资源资料,编写论述了西藏大冈底斯北部(包括班公湖-怒江成矿带、北冈底斯成矿带、中冈底斯成矿带三个成矿带)的矿产地质特征及成矿分布规律与成矿系列。班公湖-怒江成矿带包括燕山早期(洋盆形成时期,如东巧铬矿)及燕山中晚期(陆内俯冲挤压时期,如屋索拉金矿)岩浆作用有关矿床成矿系列和那曲-洛隆盆地与喜马拉雅期流体作用有关(如纳多弄铅矿)矿床成矿系列;北冈底斯成矿带矿床主要分布在申扎—嘉黎一线的北部地区(亦称冈底斯北矿带),包括玉古拉镍矿(燕山早期,岩浆岩型)、舍索铜矿(燕山中晚期,矽卡岩型为主)、尤卡朗-昂张铅矿(燕山中晚期,热液型为主)、俄龙呷砷矿(燕山晚期—喜马拉雅早期,流体-改造型为主)四个地区不同类型矿床成矿系列;中冈底斯成矿带包括近东西向两个成矿亚带,北边为革吉-雄巴-文部成矿亚带燕山中晚期(如尕尔铜金矿)及狮泉河-申扎弧-盆系演化期岩浆热液成矿作用的矿床成矿系列,南边为朗久-塔诺错-纳木错成矿亚带喜马拉雅中晚期(如甲岗钨钼铋矿)岩浆热液成矿作用的矿床成矿系列。  相似文献   

Characteristics and Altitudinal Distribution of Periglacial Decay Phenomena in the Massif of Rondane,Central Norway          下载免费PDF全文

Riwan Kerguillec 《Geografiska Annaler: Series A, Physical Geography》2015,97(2):299-315

The Norwegian massif of Rondane is part of the Scandes Mountains and is subject to polar, oceanic and continental influences. Because of its climatic context and its quartzitic structure, the massif has one of the thickest functional periglacial belts in Europe (1200 m). This belt is not fixed considering its translation in altitude since the end of the Little Ice Age. This mobility is continuing and involves periglacial decay dynamics which are revealed by numerous and various periglacial forms in the field. Because of their frequency in the massif and also their sensitivity to climate fluctuations, earth patches and small non‐sorted circles have a diagnostic value for current periglacial climate fluctuations. The major aim of this study is to propose several indicators of this periglacial decay and to highlight its consequences on periglacial belt mobility because these landforms enable the delimitation of a critical belt of decay in the massif.  相似文献   

Changeability of Movable Bed‐Surface Particles in Natural,Gravel‐Bed Channels and Its Relation to Bedload Grain Size Distribution (Scott River,Svalbard)          下载免费PDF全文

Waldemar Kociuba  Grzegorz Janicki 《Geografiska Annaler: Series A, Physical Geography》2015,97(3):507-521

The presented paper analyses the variability of grain size distribution parameters of bedload transported by the gravel‐bed Scott River (Svalbard) draining a glacier catchment with an area of 10 km². The grain size distribution analysis is one of the basic elements of identification of the fluvial transport mechanisms in gravel‐bed rivers. It is used for the determination of threshold values for bedload movement. It is also treated as an important indicator of the origin, routes of distribution, and conditions of transport and deposition of fluvial bedload. The field study in a natural proglacial gravel‐bed channel was carried out at two reaches in the mouth section of Scott River. The study revealed relatively high temporal variability and similar mean parameters of grain size distribution in conditions of low discharges. Bedload transport rates reached a mean of 71.9–76.0 kg d^?1 in channel cross‐section. Bedload texture was dominated by gravels with a proportional contribution of the fine‐grained fraction along with very fine‐grained gravels (8‐2 mm) of 38.8%. The medium‐grained fraction (16‐8 mm) constituted 33.7%, with a lower contribution from the coarse‐grained fraction (32‐16 mm) of 23.2%, and the very coarse‐grained fraction (64‐32 mm) of 4.4%. Two periods in the course of bedload transport and distribution of grain size distribution parameters were distinguished based on variation of hydro‐meteorological conditions. The first half of the measurement period was distinguished by significantly higher values of daily loads and increased contribution of the coarse‐grained and very coarse‐grained fraction (28–31% and 6.2–6.6%, respectively). During this time, the river discharged up to 94% of bedload. This resulted in a clear tendency for riverbed scouring. The second half was distinguished by generally low daily bedload transport rates (<10 kg d^?1), an increase in contribution of fine‐ and very fine‐grained gravels (42–55.6%), and a change in the tendency to aggradation. Grain size indices were more varied, and grains were usually finer and better sorted. Selective transport processes, often related to redeposition, were dominant in the channel. Along with an increase in flow velocity, conditions for material deposition became more variable. This was manifested in weaker sorting and an increase in grain diameter.  相似文献   

常用锂同位素地质标准物质的多接收器电感耦合等离子体质谱分析研究   总被引：3，自引：3，他引：0  

赵悦  侯可军  田世洪  杨丹  苏嫒娜 《岩矿测试》2015,34(1):28-39

锂同位素研究是非传统稳定同位素地球化学研究的前沿,已广泛应用于从地表到地幔的岩石圈及流体等固体地球科学的研究领域。准确测定锂同位素比值是应用该同位素体系的前提。本文报道了国际上7种常用地质标准物质(BHVO-2、JB-2、BCR-2、AGV-2、NKT-1、L-SVEC、IRMM-016)的锂同位素组成数据。分析中采用硝酸-氢氟酸混合酸消解岩石标准样品,通过3根阳离子交换树脂(AG50W-X8,200~400目)填充的聚丙烯交换柱和石英交换柱对锂进行分离富集,利用Neptune型多接收器电感耦合等离子体质谱(MC-ICPMS)测定锂同位素比值,使用标准-样品交叉法(SSB)校正仪器的质量分馏。实验得到这7种常用地质标准物质的锂同位素组成与测试精度(2SD)分别为:δ7LiBHVO-2—L-SVEC=4.7‰±1.0‰(n=53),δ7LiJB-2—L-SVEC=4.9‰±1.0‰(n=20),δ7LiBCR-2—L-SVEC=4.4‰±0.8‰(n=8),δ7LiAGV-2—L-SVEC=6.1‰±0.4‰(n=14),δ7LiNKT-1—L-SVEC=9.8‰±0.2‰(n=3),δ7LiL-SVEC—L-SVEC=-0.3‰±0.3‰(n=10),δ7LiIRMM-016—L-SVEC=0.0‰±0.5‰(n=10),这些数据在误差范围内与国际上已发表的数据一致。Li同位素分析精度可以达到大约0.5‰,长期的分析精度即外部重现性≤±1.0‰,达到了国际同类实验室水平。7种常用地质标准物质的锂同位素组成数据的发表为锂同位素研究提供了统一的标准,使地质样品的锂同位素数据的质量监控成为可能。在基质效应的研究中,使用不同量的IRMM-016配制的标准溶液过柱,深入探讨了样品量对锂同位素测定值的影响,结果表明,在现有测试精度下,只要分析样品的锂含量达到100μg/L,且不超过树脂的承载量,样品的锂同位素组成在误差范围内与真值吻合,样品量的大小不影响锂同位素测定结果的准确性。  相似文献   

含粗粒金矿样品采集加工与分析研究进展     

熊英  陈文科  田萍  吴邦朝 《岩矿测试》2015,34(1):12-18

含粗粒金矿,由于粗粒金的存在使其样品的采集、加工和分析极具挑战性,如何获得具有代表性和均匀性的化学分析样品,并提供准确的分析结果,长期以来一直是该类金矿资源勘查评价急待解决的技术难题。本文对近年来国内外含粗粒金矿样品的采集、加工和分析方法等3方面开展的研究工作及主要成果进行归纳分析,认为:1含粗粒金矿样品的采集是确保样品代表性的首要环节,含粗粒金矿样品分析结果的潜在误差有80%来源于样品采集,因此研究经济、有效的样品采集方法至关重要。2含粗粒金矿样品的加工主要从提高自然金的粉碎度,改进加工流程,选择样品加工设备等方面进行,但查明金的粒度分布及伴生矿物是拟定样品加工流程的关键。3含粗粒金矿样品的分析方法有常规的化学分析方法、批量浸金法和人工重砂加权平均法,相对于复杂的加工流程研究,后者有望成为此类样品经济有效的分析方法。本文指出,含粗粒金矿资源评价质量的误差来源于地质、采样、加工、分析等诸多方面,总体而言应最小化所有阶段误差,应特别重视样品采集方法的研究,确保采集样品的代表性是提高该类金矿资源评价质量的前提。  相似文献