罗甸县暴雨的时空分布特征分析

通过对1951—2020年罗甸县逐日降水观测资料、2010—2020年罗甸县各乡镇逐日降水观测资料的统计分析,计算出要素保证率80%的值,采用线性趋势分析、等值线分布、Mann-Kendal检验、Morlet小波方法分析罗甸县境内暴雨的时空分布特征。结果表明：近70 a罗甸县年暴雨日数、近11 a罗甸县各乡镇总年暴雨日数均缓慢增多,区域暴雨次数逐渐减少,在年际变化中,均存在显著的3 a左右周期振荡。暴雨集中发生在5—9月,近70 a占全年暴雨日数91%,各月暴雨日数时空分布差异显著,暴雨发生最多月份为6月,近70 a平均每年1.3 d,占全年暴雨日数的36%。各乡镇年平均暴雨日数分布区域性特征明显,存在2个多值区（西北部、东南部）和1个少值区（西南部）。暴雨多发生在夜间,尤其大暴雨以上量级降水在夜间发生的概率高达93%。降水强度等级从北向南逐级减小,与罗甸县略呈“撮箕口”朝南地形较一致,从西北、北、东北向南逐级减小,在西部、东北部存在较稳定的2个极端暴雨中心。各乡镇连续暴雨次数分布差异明显,呈北多南少分布。总体而言,西部在年暴雨日数、暴雨强度、连续暴雨次数及连续降水量均居全县首位,在天气预报、防汛工作中应重点关注和防范。     

昆明地区降水量时空分布特征

近年来由于降水异常所带来的干旱、城市内涝等气象灾害越来越受到人们的关注.采用回归方法对昆明12个大监站近43年来的降水量时空变化特征进行分析,发现昆明地区年降水量减少,春、夏、秋的降水也减少,但冬季降水略增加;年、四季降水有较为明显年代际变化趋势,且存在一个或多个突变点.降水量变化具有一定的区域分布特征,市区及以东以南地区夏季及年降水量偏少显著,春季降水西北部地区偏多其余偏少,秋季降水为一致减少型,冬季降水西南部减少其余大部持平或略增加.     

东海XX井复杂情况处理介绍

东海某油气田XX调整井作业过程中,钻至设计井深后,决策加深钻进以钻探深部地层的含油气性.加深钻进至5108m发生溢流,压井过程中,钻杆在731 m位置发生刺漏,导致短路循环,置换法压井过程发生井漏、阻流管汇刺漏,同时由于平台设备压力等级不足导致情况进一步复杂化.经过一系列非常规措施,最终压井成功,是一次非常规压井的成功案例.     

Numerical Prediction of Hydrodynamic Forces on A Ship Passing Through A Lock

While passing through a lock, a ship usually undergoes a steady forward motion at low speed. Owing to the size restriction of lock chamber, the shallow water and bank effects on the hydrodynamic forces acting on the ship may be remarkable, which may have an adverse effect on navigation safety. However, the complicated hydrodynamics is not yet fully understood. This paper focuses on the hydrodynamic forces acting on a ship passing through a lock. The unsteady viscous flow and hydrodynamic forces are calculated by applying an unsteady RANS code with a RNG k?ε turbulence model. User-defined function (UDF) is compiled to define the ship motion. Meanwhile, the grid regeneration is dealt with by using the dynamic mesh method and sliding interface technique. Numerical study is carried out for a bulk carrier ship passing through the Pierre Vandamme Lock in Zeebrugge at the model scale. The proposed method is validated by comparing the numerical results with the data of captive model tests. By analyzing the numerical results obtained at different speeds, water depths and eccentricities, the influences of speed, water depth and eccentricity on the hydrodynamic forces are illustrated. The numerical method proposed in this paper can qualitatively predict the ship-lock hydrodynamic interaction. It can provide certain guidance on the manoeuvring and control of ships passing through a lock.     

两次飞机增雨作业过程数值模拟分析

利用国家气象中心GRAPES业务模式耦合混合相双参数云微物理方案,对2010年12月15日的两次飞机人工增雨作业过程进行了催化数值模拟分析。分析得出:GRAPES模式基本能给出正确的中低层天气形势场和降水的动力结构,较大降水的落区和范围基本可信,降水强度较实况偏小;按照作业实况进行催化模拟具有一定的可信度,与实况降水在较强降水区域有较好的对应性;两次播撒都取得了增加降雨量的效果,24 h平均增雨量在3~5 mm,最大增雨量达7 mm,两次播撒后增雨作业区的累计降水总量较未播撒时增加约一倍;播撒有效时段在4 h内,播撒后1~2 h雨量增加最大,增雨区域初期与播撒区域一致,随时间延长而在播撒区附近扩散;第一次播撒时,播撒冰晶消耗液态水,转化成固态水,水汽流入速度加快,向液态水转化加快,液态水迅速恢复,未出现减雨现象;第二次播撒时,云中固态水争食水汽增长,液态水得不到补充,云中上升运动减弱,自然降水阶段出现减雨现象。     

Evaluation of Reanalysis Products with in situ GPS Sounding Observations in the Eastern Himalayas简

Previous studies have shown that reanalysis products contain large uncertainties in the Tibetan Plateau（TP）,and the biases are location dependent.Therefore,these products must be evaluated with in situ observations prior to their applications.In this study,the authors compare the results of several reanalysis projects with independent sounding observations recorded in the Yarlung Tsangpo River valley in the Eastern Himalayas in June 2010.These reanalysis projects include Climate Forecast System Reanalysis（CFSR）,Interim European Centre for Medium Range Weather Forecasts Reanalysis（ERA- Interim）,Japanese 25-year Reanalysis（JRA-25）,Modern Era Retrospective Analysis for Research and Applications（MERRA）,National Center for Environmental Prediction and the Department of Energy Reanalysis 2（NCEP-R2）,and NCEP Final Analysis（FNL）.Statistical quantities such as average,mean bias（MB）,root-mean-square difference（RMSD）,and correlation coefficient（R） of temperature,specific humidity,u-wind,and v-wind between 100 hPa and 650 hPa were calculated.The authors determined that the performance of each product differed with variables at different levels.The average profiles of the variables were captured by the reanalysis products,with large biases appearing at lower levels.ERA-Interim and NCEP-R2 showed the best and worst performances,respectively,for all variables.This study suggests that users should select appropriate reanalysis products according to their specific purposes for TP research.     

中华鳖Trionyx sinensis(Wiegmann)对泥鳅Misgurnus anguillicaudatus(Cantor)幼鱼的捕食效应

以规格6m×4m×1.2m的室内水泥池为实验单元,A[(37.53±7.72)mm]、B[(63.13±12.95)mm]肛长组泥鳅幼鱼为猎物,采用捕食者-猎物间捕食效应研究方法,研究了中华鳖对泥鳅幼鱼的捕食效应。结果表明:(1)中华鳖捕食泥鳅幼鱼的时段主要集中于00:00—4:00,其对A肛长组泥鳅幼鱼所具的捕食选择性与A、B肛长组间初始数量的配置比例无关;(2)中华鳖捕食泥鳅幼鱼的功能反应属Holling-Ⅱ型,其对A、B肛长组泥鳅幼鱼的理论最大捕食量分别为16.13ind/d和9.06ind/d;(3)中华鳖对A、B肛长组泥鳅幼鱼的种内干扰模型可分别由各自的指数方程表达,用来描述实验鱼初始数量、实验期间实验鱼被捕食数量以及中华鳖个数等参数的统计关系,并指导确定合理的中华鳖和泥鳅的初始放养数量。     

龙门县寒冷天气统计特征及其对人体舒适度的影响

根据龙门县1962—2012年逐日气象资料,采用线性回归、滑动平均、人体舒适度指数等方法,研究了龙门县寒冷天气统计特征及其对人体舒适度的影响。结果表明,近50年来龙门寒冷天气日数呈不显著减少趋势,减少速率每10年1.9 d,但近10年寒冷天气日数呈增加趋势。寒冷天气主要出现在12—2月,占全年的86.8%。寒冷天气可分阴冷寡照型、晴空辐射型、冷空气来袭型3种类型。部分橙色寒冷天气虽然早晚气温较低,人体感觉寒冷,但中午气温较高,人体感觉舒适;而黄色寒冷天气若为阴雨寡照型时,全天气温较低,人体感觉寒冷。     

山东沿海菲律宾蛤仔不同地理群体遗传多样性的AFLP分析

利用AFLP技术对山东沿海菲律宾蛤仔（Ruditapes philippinarum）4个野生群体（乳山、无棣、牟平、即墨）进行了遗传多样性分析。采用6对引物组合对4个群体进行扩增,共得到356个位点,乳山群体、无棣群体、牟平群体和即墨群体的多态位点比例依次为74.40%、70.50%、72.80%、74.70%,具有较高的遗传多样性水平。其中,即墨群体多态性比例最高,无棣群体多态性比例最低。聚类分析表明,各群体间的遗传距离在0.0263～0.0448之间,乳山群体和无棣群体间的遗传距离最近(0.0263),两群体首先聚在一起,随后与牟平群体和即墨群体聚在一起。     

Validation and Application of Reanalysis Temperature Data over the Tibetan Plateau

The Tibetan Plateau has substantial impacts on the weather and climate of the Northern Hemisphere,due in large part to the thermal effects of the plateau surface.Surface temperature over the Tibetan Plateau is the most important parameter in determining these thermal effects.We present a method for verifying widely used reanalysis temperature products from NCEP-R2,ERA-Interim,and JRA-25 over the Tibetan Plateau,with the aim of obtaining a reliable picture of surface temperature and its changes over the plateau.Reanalysis data are validated against the topography elevation,satellite observations,and radiosonde data.ERA-Interim provides the most reliable estimates of Tibetan Plateau surface temperature among these three reanalyses.We therefore use this dataset to study the climatology and trends of surface temperature over the Tibetan Plateau.ERA-Interim data indicate a dramatic warming over the Tibetan Plateau from 1979 to2010,with warming rates of 0.33℃ per decade in annual mean temperature,0.22℃ per decade in summer and0.47℃ per decade in winter mean temperatures.Comparison with the results of previous studies suggests that surface warming over the Tibetan Plateau has accelerated during the past 30 years.This warming is distributed heterogeneously across the Tibetan Plateau,possibly due to topographic effects.