中国冬季月地面气温的年际变化

基于观测资料和再分析资料,对我国冬季各月地面气温的年际变异时空演变以及它们之间的相互关系、相关的环流异常特征进行了统计诊断分析,并对大气内部的影响过程和机制进行解释。我国冬季各月地面气温的主要年际变异模态是除青藏高原地区外的全国一致型,其次为南北反号分布型。我国冬季1月与2月气温的主要年际变异模态之间存在显著的同相变化关系,而它们与前期12月气温的主要变异型存在一定程度的反相变化关系。我国冬季各月地面气温主要年际变异模态又与欧亚大陆更大范围的高纬—中低纬度地区气温的反号变异型直接相关。与我国冬季各月大范围的地面气温变异相关的温度异常信号存在于深厚的对流层,其中异常信号在地面最显著,其强度随高度逐渐衰减。地表温度异常可以通过地表向上长波辐射通量异常来影响近地面乃至更高层次的气温异常。在冬季各月,欧亚大陆北部上空对流层各层出现的明显西风异常加强,使得高纬度的冷空气南侵活动减弱,从而造成我国乃至更大范围且垂直深厚的气温暖异常。     

红笛鲷α-珠蛋白和β-珠蛋白基因的克隆及序列分析

应用已知的标签序列通过RACE-PCR和RT-PCR方法成功克隆红笛鲷(Lutjanus sanguineus)α-珠蛋白和β-珠蛋白基因的全长cDNA序列。α-珠蛋白和β-珠蛋白基因的cDNA全长分别为560和563 bp,开放阅读框分别为429和444 bp,各编码143和148个氨基酸,理论相对分子质量分别为15690和16400,理论等电点为7.79和6.61。氨基酸序列BLAST结果表明,红笛鲷α-珠蛋白基因和β-珠蛋白基因编码的氨基酸序列与其他鱼类的相似性分别在59%~79%和55%~80%之间。用邻接法(Neighbor-Joining)构建的α-珠蛋白基因和β-珠蛋白基因的系统发育树表明,红笛鲷与真鲷(Pagrus major)、金头鲷(Sparus aurata)和鰤(Seriola quinqueradiata)等亲缘关系较近。     

The variation of evaporation over South China and its relationships to precipitation

The evaporation rate over South China is estimated based on the Climate Prediction Center Merged Analysis of Precipitation(CMAP)data and the NCEP/DOE reanalysis II data from 1979 to 2007. The temporal variation of evaporation over South China and its relationship to precipitation are discussed. Climatologically,the evaporation rate over South China is the largest in July and smallest in March.In spring and summer,the evaporation rate is approximately one half of the precipitation rate.However,the evaporation rate is approximately equal to the precipitation rate in fall and winter.The year-to-year variation of the evaporation rate over South China is quite in phase with that of the precipitation rate in the period from February to May but out of phase with that of the precipitation rate in early winter.Over South China there is a pronounced decreasing trend in the evaporation in colder seasons and a positive correlation between the evaporation variation and the rainfall variation in spring.In summer,the abnormality of rainfall over South China is closely related to the anomalous evaporation over the northeastern part of the South China Sea and its eastern vicinity.In winter,the rainfall variation in South China has a close linkage with the evaporation variation in a belt area covering the eastern Arabian Sea,the Bay of Bengal,the southeastern periphery of the Plateau,the southern part of South China Sea and the central part of Indonesia.     

Eddy-resolving Simulation of CAS-LICOM3 for Phase 2 of the Ocean Model Intercomparison Project

A 61-year(1958–2018) global eddy-resolving dataset for phase 2 of the Ocean Model Intercomparison Project has been produced by the version 3 of Chinese Academy of Science, the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics/Institute of Atmospheric Physics(LASG/IAP) Climate system Ocean Model(CAS-LICOM3). The monthly and a part of the surface daily data in this study can be accessed on the Earth System Grid Federation(ESGF) node. Besides the details of the model and experiments, the evolutions and spatial patterns of large-scale and mesoscale features are also presented. The mesoscale features are reproduced well in the high-resolution simulation, as the mesoscale activities can contribute up to 50% of the total SST variability in eddy-rich regions. Also, the large-scale circulations are remarkably improved compared with the low-resolution simulation, such as the climatological annual mean SST(the RMSE is reduced from 0.59°C to 0.47°C, globally) and the evolution of Atlantic Meridional Overturning Circulation. The preliminary evaluation also indicates that there are systematic biases in the salinity, the separation location of the western boundary currents, and the magnitude of eddy kinetic energy. All these biases are worthy of further investigation.     

高精度磁测正常场改正和高度改正精度

地球磁场强度存在沿纬度方向和高度方向上的变化,在开展高精度磁测工作时,必须进行高度改正和正常场改正。目前普遍使用的改正方法是根据高斯球谐表达式的13级近似式、十级近似式以及一级近似式进行改正的。经计算发现,与高斯球谐表达式的13级近似式相比,当测点与基点的南北方向距离为30 km时,使用十级近似式计算的正常场改正误差为-0.21 nT;使用一级近似式计算的正常场改正的误差随测点与基点的南北方向距离增大而增大,当测点与基点的南北方向的距离大于4 km时,正常场改正误差大于1 nT;使用一级近似式计算的高度改正的误差随测点与基点高度差增大而增大,当测点与基点高度差大于300 m时,误差大于1 nT。     

滇西北春都斑岩铜矿床侵入岩岩石地球化学

春都斑岩铜矿床的侵入岩主要为闪长玢岩和花岗闪长斑岩,文章对其进行了岩石学、地球化学研究.研究表明春都斑岩铜矿床侵入岩属于钙碱性系列,产出于俯冲构造环境.闪长玢岩、花岗闪长斑岩富集大离子亲石元素Sr、K、Rb、Ba、Th,相对亏损高场强元素Ta、Nb、P、Hf、Ti.稀土元素球粒陨石标准化曲线显示轻稀土富集,分配曲线右倾...     

沁水盆地南部煤层气井增产的储层生产控制探讨

以沁水盆地南部区块煤层气生产井的工程、测试、监测数据为依据,对影响煤层气井产能的储层生产控制因素进行了分析,探讨了优化储层生产控制、提高煤层气井产能的工程措施,重点研究了水力压裂工艺施工参数与煤层气井产能的关系,提出了有利于提高煤层气井产能的水力压裂工艺施工参数。结果表明：合理控制钻井液的密度与粘度,可提高煤层气井的产能;煤层气井的产能与固井工艺中的水泥浆密度与用量呈现负相关关系;水力压裂采用变砂比、控制压裂液、变排量等施工工艺和优化的工艺参数值可有效提高煤层气井气产量。     

广义索末菲积分的离散复镜像算法

本文对多分层媒质并矢格林函数中的索末菲积分,用Prony方法对其被积函数分式部分用指数函数逼近.利用索末菲恒等式,无穷积分就可化为闭合的级数形式.该闭合形式可看作一串离散镜像在观察点的解.所得结果与数值积分结果吻合很好.     

高纬电离层中非麦克斯韦分布等离子体的非相干散射谱的模拟

使用一个修正的双麦克斯韦分布函数，通过最小均方适应技术使它与高纬电离层Ｆ区中离子的非麦克斯韦速度分布函数相适配．结果表明，使用这样的分布函数可以简化非相干散射谱的计算，并有助于简化高纬地区电离层非相干散射谱的反演．     

Extended Impact of Cold Air Invasions in East Asia in Response to a Warm South China Sea and Philippine Sea

During boreal winter, the invasion of cold air can lead to remarkable temperature drops in East Asia which can result in serious socioeconomic impacts. Here, we find that the intensity of strong synoptic cold days in the East China Sea and Indochina Peninsula are increasing. The enhanced synoptic cold days in these two regions are attributed to surface warming over the South China Sea and Philippine Sea(SCSPS). The oceanic forcing of the SCSPS on the synoptic cold days in the two regions is veri...