黄河源积雪期土壤温湿及冻融特征分析与模拟

利用2017~2018年黄河源地区野外观测站数据,对黄河源区两个积雪期内土壤温湿及冻融特征进行了分析,并与CLM4.5模式模拟的积雪期土壤温、湿度及辐射分量进行了对比,结果表明：CLM4.5能很好地模拟出整个积雪期土壤温度的变化趋势;对不同土壤层在不同冻结阶段土壤含水量的模拟有所差异：在完全冻结阶段,对5cm土壤层含水量模拟偏高,而80cm偏低,对10~40cm土壤层含水量的模拟偏差较小;由于降雪及土壤冻融过程主要发生在积雪期,积雪反照率使得净辐射模拟在降雪时段偏差较无降雪时段略大。     

Factors Influencing Diurnal Variations of Cloud and Precipitation in the Yushu Area of the Tibetan Plateau

Using the cloud radar, ground observations, and ECMWF Reanalysis v5 (ERA5) data, we investigate the factors in-fluencing nighttime precipitation during summer i...     

海温和极冰对副热带高压季节性北跳影响的数值模拟

道德以南海区域平均的候平均ＯＬＲ值下降至２３５Ｗ／ｍ,同时纬向风由东转成西为定义标准确定南海季风从１９７９到１９９４年间爆发的平均日期是５月第４候,然后对１６年的ＯＬＲ场,风场及θＸ场的时段叠加合成图进行了分析,认为南海夏季风的建立是南海－西太平洋系统所造成。     

夏季巴丹吉林沙漠残余层与深厚对流边界层的关系研究

利用2012年7月"巴丹吉林沙漠陆气相互作用及其对区域气候的影响研究"实验所得到的观测资料和中尺度气象模式WRF,对夏季巴丹吉林沙漠对流边界层高度发展的特征及其影响因素进行了研究。结果表明:(1)2012年7月在巴丹吉林沙漠连续观测到厚度超过3500 m的深厚对流边界层,其最大高度可达4000 m以上;当这种深厚对流边界层出现之前,当地中低层大气(1000~4000 m)存在近中性的残余层,而在没有近中性残留层出现时,即便地表感热通量较大,当天最大对流边界层高度却明显偏低;(2)WRF模式模拟结果表明残余层稳定度和对流边界层高度之间的负相关关系在空间区域成立,残余层位温直减率与当地对流边界层高度在时间和空间分布上都呈现显著的负相关关系;残余层位温直减率与对流边界层高度的空间相关系数最大值可达-0.51;(3)观测和模拟结果均表明残余层稳定度会直接影响由感热通量产生的对流边界层的发展效率,进而影响对流边界层的最大高度。通过研究发现,除感热通量外,近中性的残余层是巴丹吉林地区深厚对流边界层出现的关键条件之一。     

Numerical simulation of the critical scale of oasis maintenance and development in the arid regions of Northwest China

Oasis is a special geographic landscape among the vast desert/Gobi in Northwest China (NWC). The surface sensitive heat flux and latent heat flux at Zhangye Oasis during 1 to 11 August 1991 are simulated using the NCAR nonhydrostatic mesoscale model MM5 Version 3. The horizontal grid resolution is set as 1km. By comparing the simulation results with HEIFE observations, it is proved that the model can be used to simulate the surface energy and water mass exchange of arid and semiarid regions in NWC.Based on the above results, the influence of different oasis scales on the local atmospheric field near the ground surface, and the critical scale of oasis maintenance, in NWC are studied dynamically. The following conclusion is obtained: the local thermal circulation between the oasis and the desert/Gobi is formed in the oasis downstream if the oasis scale is larger than 4 km. This local thermal circulation between the oasis and the desert adjacent to the oasis helps to conserve water vapor over the oasis. At the sametime, it transfers the abundant water vapor from the oasis into the desert/Gobi near to the oasis to supply relatively plentiful water vapor for desert crops to grow on the fringe of the oasis. So, it is advantageous for oasis extension. However, if the scale of the oasis is smaller than 4 km, it is not easy for the local thermal circulation between the oasis and the desert/Gobi to take shape. This study provides a new standpoint for oasis maintenance and development.     

Dataset of Comparative Observations for Land Surface Processes over the Semi-Arid Alpine Grassland against Alpine Lakes in the Source Region of the Yellow River

Thousands of lakes on the Tibetan Plateau(TP) play a critical role in the regional water cycle, weather, and climate. In recent years, the areas of TP lakes underwent drastic changes and have become a research hotspot. However, the characteristics of the lake-atmosphere interaction over the high-altitude lakes are still unclear, which inhibits model development and the accurate simulation of lake climate effects. The source region of the Yellow River(SRYR) has the largest outflow lake and freshw...     

复杂地形条件下嵌套细网格模式35例数值预报的总结

本文利用一适合复杂地形区的有限区域预报模式系统，分别采用欧洲中期天气预报中心的格点资料和我国国家气象中心的ＤＣＤ电码资料，对１９８１年７月１－３０日和１９８８年８月１０－１４日两时段共３５天作了４８小时预报。形势场和降水预报的主客观评分表明，该模型系统已具备了在业务环境下作预报的可能，该模型预报性能良好，具有较好的强降水预报的能力。     

自贡市臭氧浓度变化特征及其与气象因素的相关性研究

根据2014-2018年自贡市逐日大气污染物监测数据及地面气象数据,采用统计方法,分析了自贡市臭氧变化特征及其与气象因素的关系,结果表明:2014-2018年内自贡市O3-8h(1日中最大连续8 h O3浓度均值)月平均浓度峰值出现在7月份,从年平均浓度变化上看,自贡市O3-8h浓度每年平均增长10.6μg/m3.各季...     

1979年东亚地区的夏季风环流特征及其与降水的关系

本文用1979年5—8月份美国华盛顿发布的格点风资料(5°×5°网格)、卫星云图、中央气象局出版的《中国高空气象》、历史天气图等资料计算了低纬地区(30°N—10°S)逐日110°E115°E、120°E三个经度上的平均经圈环流。按其环流的主要特征和性质分为三类,然后用合成分析的方法求出各类的平均环流。并分析了其平均垂直环流和水平环流及降水分布,在此基础上概括出各类三维环流图象及其与降水的关系。这些环流型,较好地反映了东亚夏季风环流的季节特征和环流特征。