一次梅雨锋暴雨过程数值模拟的云微物理参数化敏感性研究     

周志敏  崔春光  胡扬  康兆萍 《大气科学》2021,45(6):1292-1312

梅雨锋暴雨中的云微物理过程对降水的演变有着重要影响。本文通过WRF模式（3.4.1版本）,针对2018年6月29～30日一次梅雨锋背景下的暴雨过程进行数值模拟,分别采用了Morrison、Thompson和MY云微物理参数化方案进行对比分析,结果发现:（1）三个方案模拟的背景场在天气尺度上,都与ERA5再分析资料一致,能够模拟出有利于强降水发生的环流场。云微物理过程对梅雨期暴雨的局地环流有着显著影响,不同方案存在明显差异,本次过程中,Thompson方案模拟出更强的局地环流系统变率和上升气流。三个方案的模拟降水均有所夸大,小时降水率始终大于观测值。冰相粒子融化或雨滴搜集云滴的高估可能是造成降水模拟值偏强的重要原因之一,总体来看,Morrison方案的模拟效果相对最优。（2）冰相粒子融化、雨滴搜集云滴是雨滴增长的关键源项,蒸发则是其最重要的汇项。总的来说,雨滴对云滴的搜集量大于冰相粒子融化。但上述过程在不同方案中存在空间上的差异,从而使得模拟降水的空间分布存在差异。（3）Thompson方案中,冰相粒子融化量最大,雨滴蒸发项显著大于其它两个方案,在底层表现得最为明显。同时,该方案水汽凝结效应最强,使得雨滴搜集更多云滴。该方案模拟的雨滴最多,降水最强。该方案中凝华的主要产物为雪,且其在与过冷水碰并增长过程中占主导地位,故模拟的雪最多。（4）Morrison方案中,水汽主要凝华为雪和少量霰（冰晶忽略不计）;Thompson方案中水汽基本凝华为雪,其它冰相粒子极少;MY方案中,水汽主要凝华为雪和冰晶,冰晶总量略少于雪,但显著大于其它方案。（5）云滴在凇附过程中的总体贡献大于雨滴。Morrison和MY方案中,霰粒子搜集云滴增长的量均最大。Morrison方案中,其它凇附过程不同程度发挥作用,而MY方案中,其它凇附过程几乎可忽略不计。并且,霰粒子搜集云滴的增长量大于凝华过程产生的雪粒子总量。贝吉龙及凇附效应的差异,是不同方案中冰相粒子分布差异的关键原因之一。  相似文献   

1970-2007年西藏念青唐古拉峰南、北坡冰川显著退缩   总被引：7，自引：3，他引：4  

康世昌  陈锋  叶庆华  井哲帆  秦大河  任贾文 《冰川冻土》2007,29(6):869-873

1999年和2007年夏季,利用GPS技术先后对念青唐古拉峰(念峰)南、北坡的5条冰川末端位置进行了实地测量.结果表明:同1970年比较发现,过去近40 a来5条冰川退缩显著,1970-2007年间念峰北坡的拉弄和扎当冰川与南坡的爬努冰川末端平均退缩速率均接近10.0 m.a-1;西布冰川在1970-1999年间达到38.9 m.a-1,而爬努冰川流域海拔较高的小冰川5O270C0049退缩幅度较小,为4.8 m.a-1.2007年野外观测发现,爬努冰川1970年代的积累区有冰面河形成.念峰周围的冰川变化,不仅仅是末端的显著退缩,而且消融区面积也在扩大.  相似文献   

Placement Optimization Method of FPSO Gas Detectors Based on Leakage Risk     

KANG Jichuan  SUN Chongwen  JIN Peng  YAN Fasuo  SUN Liping 《中国海洋大学学报(英文版)》2022,21(1):49-61

As the first step of the fire/gas-detection systems of floating production storage and offloading(FPSO)units is to iden-tify leakage accidents,gas detectors play an important role in controlling the leakage risk.To improve the leakage scenario detection rate and reduce the cumulative risk value,this paper presents an optimization method of the gas detector placement.The probability density distribution and cumulative probability density distribution of the leakage source variables and environmental variables were calculated based on the Offshore Reliability Data and the statistical data of the relevant leakage variables.A potential leakage sce-nario set was constructed using Latin hypercube sampling.The typical FPSO leakage scenarios were analyzed through computational fluid dynamics(CFD),and the impacts of different parameters on the leakage were addressed.A series of detectors was deployed according to the simulation results.The minimization of the product of effective detection time and gas leakage volume was the risk optimization objective,and the location and number of detectors were taken as decision variables.A greedy extraction heuristic algo-rithm was used to solve the optimization problem.The results show that the optimized placement had a better monitoring effect on the leakage scenario.  相似文献   

2022年1月8日青海门源M_S6.9地震同震形变场及地下位错反演     

万秀红  屠泓为 《中国地震》2022,38(1):21-29

针对2022年1月8日青海门源M_S6.9地震,基于Sentinel-1A卫星的SAR影像获取了本次地震的同震形变场,并进行计算分析,运用SDM程序反演地下静态位错。初步结果如下：①本次地震震中位于蝴蝶状分布的形变图中心,抬升盘与下降盘之间的破裂迹线明显,破裂迹线长约24km,形变中心位于托莱山与冷龙岭断裂交汇处。②降轨数据显示,在断层区域视线向（LOS）形变量最小约-0.55m（远离卫星）,最大约0.68m（靠近卫星）;升轨数据显示,在断层区域视线向（LOS）形变量最小约-0.49m（远离卫星）,最大约0.42m（靠近卫星）。③对中国地震局发布的门源6.9级地震烈度图和本研究获取的地震形变图进行叠加分析,可以看出二者吻合度较高,地表有较明显形变所涉及区域约0.4万km²。④运用降轨InSAR数据反演得出地下最大位错量约3.29m,深度4.75km,在近地表位错破裂长度可达30km,地表有明显破裂的区域长约25km,与中国地震局科考工作每日情况的结果基本一致。  相似文献   

山西地区地震综合概率预测模型及回溯性检验     

郭文峰  刘瑞春  王霞  李宏伟  曹志勇 《地震地磁观测与研究》2022,43(3):1-9

概率地震危险性分析是对相关区域地震活动水平的估计,是量化地震危险性的有效手段。基于泊松分布模型获得山西地区背景地震概率,结合每个单项方法预测效能获取的指标权重,采用综合概率法得到山西地区基于多种单项预测方法的地震综合概率模型。对 1985年以来山西地区 M_S ≥ 5.0地震进行回溯性检验,结果表明：异常点受控于统一应力场,震前各类（包括测震、形变、电磁以及流体学科）预测指标均存在且表现出准同步性;震级大小与异常数量呈一定正相关性,震级越大,异常指标越多,综合概率值越大。  相似文献   

High-resolution structure-from-motion models covering 160 km-long surface ruptures of the 2021 MW 7.4 Madoi earthquake in northern Qinghai-Tibetan Plateau     

Jing Liu-Zeng  Wenqian Yao  Xiaoli Liu  Yanxiu Shao  Wenxin Wang  Longfei Han  Yan Wang  Xianyang Zeng  Jinyang Li  Zijun Wang  Zhijun Liu  Hongwei Tu 《地震研究进展（英文）》2022,2(2):100140

The 22 May 2021 M_W 7.4 Madoi, Qinghai, China earthquake presented a rare opportunity to apply the modern unmanned aerial vehicle (UAV) photography method in extreme altitude and weather conditions to image surface ruptures and near-field effects of earthquake-related surface deformations in the remote Tibet. High-resolution aerial photographs were acquired in the days immediately following the mainshock. The complex surface rupture patterns associated with this event were covered comprehensively at 3–6 cm resolution. This effort represents the first time that an earthquake rupture in the interior of the Qinghai-Tibetan Plateau has been fully and systematically captured by such high-resolution imagery, with an unprecedented level of detail, over its entire length. The dataset has proven valuable in documenting subtle and transient rupture features, such as the significant mole-tracks and opening fissures, which were ubiquitous coseismically but degraded during the subsequent summer storm season. Such high-quality imagery also helps to document with high fidelity the fractures of the surface rupture zone (supplements of this paper), the pattern related to how the faults ruptured to the ground surface, and the distribution of off-fault damage. In combination with other ground-based mapping efforts, the data will be analyzed in the following months to better understand the mechanics of earthquake rupture related to the fault zone rheology, rupture dynamics, and frictional properties along with the fault interface.  相似文献   

甘肃寨上金矿南矿带构造叠加晕实用模型及深部找矿预测     

王斌  宋伊圩  孙彪  杨可  马振宇  康成鑫  张旺  蒋东祥  唐源壑  杨洋  姬省军  牛秋生 《现代地质》2021,35(6):1504-1514

为了研究甘肃寨上金矿南矿带矿体隐伏规律,预测深部找矿远景,基于构造叠加晕找矿方法对该矿床南矿带深部找矿潜力进行探讨。对南矿带32号脉9种金属元素(Au、Ag、As、Bi、Cu、Pb、Sb、W、Zn)的测试数据进行数学地质分析,结果表明Au与As具有较好的相关性,是找矿的指示元素;As与Sb、Cu与Bi的相关系数分别为0.586、0.945,可能与它们在热液上升过程中靠近矿体的头部和尾部有关。基于对矿区9种元素的数学统计分析并与中国金矿床原生晕综合轴向(垂向)分带序列对比,得到寨上矿区理想原生晕分带序列为:As-Sb(前缘晕)→Pb-Ag-Au-Zn-W(近矿晕)→Cu-Bi(尾晕);根据改良的格里戈良分带指数法得到各勘探线轴向分带序列,前、尾晕共存等“反分带”现象的出现表明存在多次热液叠加作用。使用克里金插值法得到衬值晕分带图,显示矿体向东倾覆,含矿热液应从东南向西北运移,剥蚀程度自东向西加强。在野外地质工作的基础上,结合矿区地质特征和元素空间分布规律,建立了南矿带构造叠加晕实用模型。根据原生晕找矿特征标志,32号脉东南部67线深处的有利成矿空间指示有矿,并将其定成预测靶位。通过布设钻孔ZK67-0验证了预测靶位的准确性,表明构造叠加晕实用模型在寨上金矿找矿预测具有可行性。  相似文献   

华南石英脉型钨矿床扇状成矿的规律及其找矿意义     

方贵聪  王登红  冯佐海  付伟  康志强  吴家旭  赵云彪  童启荃  杨明 《大地构造与成矿学》2021,45(3):523-533

钨是中国、美国、英国、欧盟等国家的战略性关键矿产,如何在已知矿区外围寻找新的钨矿资源是当前找矿工作面临的一大难题.本文通过广泛调研钨矿床野外地质事实及基础地质资料,指出江西茅坪、东坪、淘锡坑,广西社垌,广东梅子窝等石英脉型钨矿床具有扇状成矿的规律,即于花岗岩体顶部形成两组相向倾斜的"双胞胎"矿脉,横剖面呈扇状.扇状容矿裂隙系统可能是在花岗岩浆主动上侵动力、区域水平构造应力、岩层自身重力等联合作用下形成的.此规律对于在已知矿脉组外围寻找与之相向倾斜的另一矿脉组具有重要指导意义,以江西盘古山钨矿床为例,推断矿区内除了3组已知南倾矿脉之外,还可能发育另外三组北倾矿脉.  相似文献   

Geothermal Power Generation Potential in the Eastern Linqing Depression     

KANG Fengxin  ZHAO Jichu  TAN Zhirong  SUI Haibo  SHI Meng 《《地质学报》英文版》2021,95(6):1870-1881

China has been the leading country worldwide in direct geothermal utilization for a rather long time, which has contributed significantly to reducing carbon emissions. But the installed capacity of geothermal power generation in China is very small, and there are only a few geothermal power plants in China, specifically in Tibet, including the well-known Yangbajing geothermal power plant. Therefore, it is anticipated that more high-temperature geothermal resources will be discovered in order to promote China’s power generation. There is potential for high-enthalpy geothermal in the Eastern Linqing Depression in Shandong Province, where geothermal energy is stored in Ordovician and Cambrian carbonate strata. Based on the geothermal gradient in Cenozoic strata and the depth of the target geothermal reservoir, the temperature distribution pattern of the reservoir was analyzed, and two “sweet points” were identified in the Yucheng geothermal field and the Guanxian geothermal field, where the reservoir temperature is predicted to be higher than 200°C at a depth of less than 8000 m. Due to the low karst fissure ratio and the insufficient geothermal fluid in the geothermal reservoir, it is recommended that an enhanced geothermal system be set up, to increase the permeability of the natural fracture system in the carbonate formations and provide sufficient fluid for power generation through reinjection of used geothermal fluid. The power generation capacity of the two geothermal fields was estimated using a volumetric method, revealing a power generation capacity of 1621.02 MWe for the Yucheng geothermal field, and 1287.19 MWe for the Guanxian geothermal field.  相似文献   

青海玛多“5·22”M_S7.4级地震的同震地表破裂特征、成因及意义     

盖海龙  姚生海  杨丽萍  亢太波  殷翔  陈庭  李鑫 《地质力学学报》2021,27(6):899-912

2021年5月22日2时4分在青海省果洛藏族州玛多县境内发生M_S7.4级地震,此次玛多M_S7.4级地震是2008年汶川M_S8.0级大地震之后中国震级最大的一次地震,及时查明其同震地表破裂展布及特征,对于正确认识发震构造和区域防震减灾具有重要意义。根据震后现场调查,结合高分辨率卫星遥感图像的解译分析、余震数据和典型地震地表破裂的无人机低空摄影测量等结果,初步获得了此次地震6处典型地震地表破裂的特征。结果发现:此次玛多地震的地表破裂主要沿已知的东昆仑断裂带的南侧分支断裂昆仑山口-江错断裂的东南段分布,分析表明其中的江错断裂应是此次地震的发震断层;同震破裂的西段总体走向275°~300°,主要表现为挤压鼓包和雁列式张裂隙的斜列组合,其中江错贡麻段至江多村段出现了明显的1.4~0.8 m的垂直位移,指示该段可能具有较明显的正断层成分;中部黄河乡段主要由一系列呈左阶斜列的北西向P剪切裂缝和右阶雁行排列的北东向张裂隙构成,走滑位移较小;而东段地表破裂出现了多个分支,其中北支昌马河段主要由一系列雁行排列的张裂隙组成,总体走向为260°,与断裂西段的走向明显不同;地震造成的最大左旋位移出现在西段的错尔加拉破裂段,约2.8 m,指示此次地震地表破裂带的走滑位移主要呈从西向东的单侧扩展-衰减特征。考虑到此次玛多地震出现在东昆仑主干断裂南侧的巴颜喀拉地块内部,表明该地块内部具有发生7级以上大地震的能力,因此,巴颜喀拉地块内部强震活动的孕震条件和机理应该是未来需要进一步关注的科学问题。   相似文献