Remote impacts from the tropical Indian Ocean on haze pollution in January over the Yangtze River Delta

近年来,长三角霾事件频发,对人类和生态系统健康造成了严重危害,结果表明:热带印度洋12月海温与长三角1月霾日数呈显著正相关,特别是1999-2017年.12月,海温正异常加热上层空气,1月在对流层上层激发类似MatSuno-Gill模态和一系列Rossby波列,将信号传输至长三角,随后向下游日本海和阿留申群岛传播.长三...     

我国洞体应变固体潮调和分析结果

本文扼要介绍了我国洞体应变观测现状,公布了18个台站的调和分析结果,同时公布了国外同类仪器优质台站的计算结果,以作比较。     

浅谈企业如何增强凝聚力

一个企业要发展,必须要有自己的人力资源优势。而吸引优秀的人力资源,必须建立以人为本的人力资源管理政策,一个优秀企业应从职业生涯规划、员工培训与发展、绩效考评、薪酬激励、关注心理需求等五个与员工切身利益方面进行规划以此增强企业的凝聚力。     

中国区域月平均温度和降水的模式可预报性分析

基于中国台站降水和温度观测资料、中国气象局国家气候中心月动力延伸预报的回算和预测结果讨论了中国区域月平均温度和降水模式可预报性的时空变化特征。文中以持续性预报来表征中国区域月平均温度和降水受外强迫影响下的可预报性,持续性预报技巧存在明显的年际和年代际变化特征;春末夏初和秋季预报评分相对偏低;在中国区域气候变暖和平均降水强度极值增加的背景下,温度的持续性预报评分有明显提高,降水的持续性预报略有下降。月动力延伸预报对月降水和温度的预报能力也存在明显的年际和年代际变化特征;与持续性预报相比,月动力延伸温度预报总体优于持续性预报,降水预报在初春略差,温度预报在8月相对最低。近20余年,月动力延伸预报相对于持续性预报的温度和降水的均方根误差技巧均大于零,其年际变化表现为模式对降水的预测略有提高。两种预报评估结果的空间分布分析表明月动力延伸预报达到显著性水平的正相关区域总体上比持续性预报的范围大,并基本涵盖了持续性预报的高相关区。原因是可预测信息部分来源于外强迫异常的影响,部分来源于对大气内部动力过程的模拟。     

Characteristics of land surface heat and water exchange under different soil freeze/thaw conditions over the central Tibetan Plateau

Freezing and thawing processes at the soil surface play an important role in determining the nature of Tibetan land and atmosphere interactions. In this study, land surface water and heat exchanges under different freezing and thawing conditions over the central Tibetan Plateau were investigated using observations from the Coordinated Enhanced Observing Period/Asia‐Australia Monsoon Project on the Tibetan Plateau, and the Simultaneous Heat and Water Model. During the freezing and thawing stages, significant diurnal variation of soil temperature resulted in a diurnal cycle of unfrozen water content at the surface. Radiation and energy components and evapotranspiration averaged over four freeze/thaw stages also changed diurnally. On average, the surface albedo (0·68) during the completely frozen stage was sharply higher than those during the freezing, thawing, and completely thawed stages due to the snow cover. The Bowen ratios were 3·1 and 2·5 in the freezing and thawing stages, respectively, but the ratio was only 0·5 in the completely thawed stage. Latent heat flux displayed distinctly better correlation with unfrozen soil water content during the freezing and thawing stages than during the completely frozen and thawed stages. This implies that the diurnal cycle of unfrozen soil water, resulting from diurnal freeze/thaw cycles at the surface, has a significant impact on latent heat flux. A surface energy imbalance problem was encountered, and the possible sources of error were analysed. Copyright © 2011 John Wiley & Sons, Ltd.     

尼泊尔Mw7.8地震对珠峰区域内冰川形变及流速的影响

本文以L波段的ALOS PALSAR-2数据为基础,采用长时间序列InSAR技术对2014年9月至2019年8月的青藏高原区域进行动态监测,结合偏移量追踪法获取部分冰川在尼泊尔地震前后分别在距离向、方位向和水平方向的冰川流速分布结果。结果表明:在监测时段内,研究区普遍存在沉降现象,仅在个别年份出现小幅度的抬升,研究区最大年平均形变速率可达-203.1 mm/a,认为此次地震对研究区的时序观测结果的波动有特殊影响;在研究时期内部分冰川流速在地震后的相当长的一段时间内大幅度增加,最大速度可达2.645 m/d,认为地震是导致冰川流速急剧增加的原因之一。     

Late Cretaceous Transpressional Fault System: A Case Study of the Yishu Fault Belt, Shandong Province, Eastern China

On the basis of field observations of the structures of three profiles from the Linshu region, deformation characteristics and the tectonic background of the Yishu fault belt in the Late Cretaceous–Early Cenozoic have been discussed in detail.Three structural profiles, whose deformations consist mainly of earlier transpressional faults and later normal faults, were developed for the Mengtuan Formation of the Lower Cretaceous Dasheng Group.Typical positive flower structures, duplex structures, and break-through faults were found in these profiles.On the basis of analyses of the structural deformation and previous geochronological studies, it was concluded that the earlier transpressional faults of the profiles were triggered by the sinistral transpression of the Yishu fault belt in the Late Cretaceous–Early Paleogene, and that the later normal faults, formed during the Late Paleogene–Neogene extension, truncated the earlier transpressional faults.With consideration of the tectonic evolution of the Tan-Lu fault belt and the different drift directions of the Pacific plate since the Cretaceous, we suggest that the major tectonic events of the Late Cretaceous–Neogene in eastern China were mainly controlled by the subduction of the Pacific plate.     

Analysis of Sampling Error Uncertainties and Trends in Maximum and Minimum Temperatures in China简

In this paper we report an analysis of sampling error uncertainties in mean maximum and minimum temperatures （Tmax and Tmin） carried out on monthly,seasonal and annual scales,including an examination of homogenized and original data collected at 731 meteorological stations across China for the period 1951-2004.Uncertainties of the gridded data and national average,linear trends and their uncertainties,as well as the homogenization effect on uncertainties are assessed.It is shown that the sampling error variances of homogenized Tmax and Tmin,which are larger in winter than in summer,have a marked northwest-southeast gradient distribution,while the sampling error variances of the original data are found to be larger and irregular.Tmax and Tmin increase in all months of the year in the study period 1951-2004,with the largest warming and uncertainties being 0.400℃ （10 yr）-1 ＋ 0.269℃ （10 yr）-1 and 0.578℃ （10 yr）-1 ＋ 0.211℃ （10 yr）-1 in February,and the least being 0.022℃ （10 yr）-1 ＋ 0.085℃ （10 yr）-1 and 0.104℃ （10 yr）-1 ＋0.070℃ （10 yr）-1 in August.Homogenization can remove large uncertainties in the original records resulting from various non-natural changes in China.     

山东嘉祥青山省级地质公园主要地质遗迹成因及评价

青山省级地质公园地质遗迹非常丰富,总面积2.43 km2,是以典型三山子组地层剖面、丰富构造形迹、泉水景观和洞穴类地质遗迹为主的小型地质公园。通过对区内地质遗迹的野外调查及室内综合研究分析,总结了公园内主要地质遗迹成因并对其评价,必将促进该区地质遗迹合理开发保护利用。     

An exceptionally heavy snowfall in Northeast china: large-scale circulation anomalies and hindcast of the NCAR WRF model

In Northeast China (NEC), snowfalls usually occur during winter and early spring, from mid-October to late March, and strong snowfalls rarely occur in middle spring. During 12?C13 April 2010, an exceptionally strong snowfall occurred in NEC, with 26.8?mm of accumulated water-equivalent snow over Harbin, the capital of the most eastern province in NEC. In this study, the major features of the snowfall and associated large-scale circulation and the predictability of the snowfall are analyzed using both observations and models. The Siberia High intensified and shifted southeastward from 10?days before the snowfall, resulting in intensifying the low-pressure system over NEC and strengthening the East Asian Trough during 12?C13 April. Therefore, large convergence of water vapor and strong rising motion appeared over eastern NEC, resulting in heavy snowfall. Hindcast experiments were carried out using the NCAR Weather Research and Forecasting (WRF) model in a two-way nesting approach, forced by NCEP Global Forecast System data sets. Many observed features including the large-scale and regional circulation anomalies and snowfall amount can be reproduced reasonably well, suggesting the feasibility of the WRF model in forecasting extreme weather events over NEC. A quantitative analysis also shows that the nested NEC domain simulation is even better than mother domain simulation in simulating the snowfall amount and spatial distribution, and that both simulations are more skillful than the NCEP Global Forecast System output. The forecast result from the nested forecast system is very promising for an operational purpose.