全球寒武系四统划分框架正式确立

国际地层委员会最近陆续发布了2005和2006年版《国际地层表》(http://www.stratigraphy.org/cheu.pdf),这两张新表较以往各版最为突出的变动是将寒武系分为四个统和十个阶,不再采用国际地学界沿用了近一百七十年的上、中、下3统的传统划分方法。这一改写是全球地层学的重大事件     

Trends in stream and river temperature

Information on past and likely future trends in water temperature from different parts of the world is collated. The potential causes of trends in the thermal regimes of streams and rivers are many, but the existing database of water temperature information is inadequate to provide a global perspective on changes during the recent, let alone the more remote, past. Data from Europe suggest that warming of up to ca. 1°C in mean river temperatures has occurred during the 20th century, but that this trend has not been continuous, is distorted by extreme hydrological events, is not correlated with simple hydrometeorological factors and has been influenced by a variety of human activities. Predictive studies indicate that an accelerated rise in stream and river temperatures will occur during the next century as a consequence of global warming. However, forecasts must be tentative because future climatic conditions are uncertain and interactions between climate, hydrological and vegetation changes are complex.     

面向离散点的空间权重矩阵生成算法与实证研究

采用阈值法和k-近邻法度量空间上离散点间的空间邻接关系,针对不同的距离计算方式(欧式距离和曼哈顿距离)设计了面向离散点的空间权重矩阵生成算法,使用C#语言在计算机上实现。用该算法对收集的8 367个常州市地价样点构建了不同土地用途地价样点的空间权重矩阵,并计算出分用途的常州市城市地价空间自相关指数。     

Using Statistical Downscaling to Quantify the GCM-Related Uncertainty in Regional Climate Change Scenarios： A Case Study of Swedish Precipitation

There are a number of sources of uncertainty in regional climate change scenarios. When statistical downscaling is used to obtain regional climate change scenarios, the uncertainty may originate from the uncertainties in the global climate models used, the skill of the statistical model, and the forcing scenarios applied to the global climate model. The uncertainty associated with global climate models can be evaluated by examining the differences in the predictors and in the downscaled climate change scenarios based on a set of different global climate models. When standardized global climate model simulations such as the second phase of the Coupled Model Intercomparison Project （CMIP2） are used, the difference in the downscaled variables mainly reflects differences in the climate models and the natural variability in the simulated climates. It is proposed that the spread of the estimates can be taken as a measure of the uncertainty associated with global climate models. The proposed method is applied to the estimation of global-climate-model-related uncertainty in regional precipitation change scenarios in Sweden. Results from statistical downscaling based on 17 global climate models show that there is an overall increase in annual precipitation all over Sweden although a considerable spread of the changes in the precipitation exists. The general increase can be attributed to the increased large-scale precipitation and the enhanced westerly wind. The estimated uncertainty is nearly independent of region. However, there is a seasonal dependence. The estimates for winter show the highest level of confidence, while the estimates for summer show the least.     

Intraseasonal oscillation intensity over the western North Pacific:Projected changes under global warming

本文利用8个CMIP5模式的日资料,预估了RCP4.5和RCP8.5情景下全球增温达1.5℃和2.0℃时西北太平洋夏季30～60天和10～20天季节内振荡(ISO)强度的变化情况.大多数模式都认为,无论增温水平或情景如何,预估结果均显示从中南半岛南部到菲律宾以东的带状区域内ISO强度增加,并且关键气象要素背景的变化会对...     

2022年夏季中国高温干旱气候特征及成因探讨

2022年夏季,中国中东部发生了极端高温干旱气候异常,给经济、农业、人民生活造成了严重影响。本文回顾了此次高温干旱气候异常的时空特征,分析了其主要成因。2022年夏季,中国中东部区域平均的极端高温频次、日最高温度平均值、高温日数等指标均达到了1979年以来的最大值,区域平均降水则达到了1979年以来的最低值。此次气候异常主要是由于夏季中国中东部受强大的高压系统控制,与偏强的西太副高、中纬度的西风带扰动以及热带海温的影响有关。此外,本文探讨了全球增暖趋势对极端高温事件增多的影响,以及未来中国地区高温和干旱事件的可能变化。     

GPS变形监测动态数据处理中卡尔曼滤波的应用

介绍了卡尔曼滤波的基本原理,针对常规GPS变形监测数据处理中存在着不连续、非实时的缺点,结合卡尔曼滤波的特点,运用三峡实测数据对GPS变形监测动态数据处理中卡尔曼滤波的应用进行研究。并采用各点点位位移速度图对所建立的函数模型进行验证,同时对状态方程的建立及初始值的选取进行分析总结。     

Adjustment time of the first baroclinic Rossby wave in the global oceans

1Introduction Planetary waves involve the main processes bywhich perturbation signal in one part of the ocean istransferred to another part.In the1970s,mostof theprevious theoretical studies focus on the local Ekmanpumping and the nondispersive long baroc…     

Future Changes in Extreme High Temperature over China at 1.5℃-5℃ Global Warming Based on CMIP6 Simulations

Extreme high temperature(EHT)events are among the most impact-related consequences related to climate change,especially for China,a nation with a large population that is vulnerable to the climate warming.Based on the latest Coupled Model Intercomparison Project Phase 6(CMIP6),this study assesses future EHT changes across China at five specific global warming thresholds(1.5℃-5℃).The results indicate that global mean temperature will increase by 1.5℃/2℃ before 2030/2050 relative to pre-industrial levels(1861-1900)under three future scenarios(SSP1-2.6,SSP2-4.5,and SSP5-8.5),and warming will occur faster under SSP5-8.5 compared to SSP1-2.6 and SSP2-4.5.Under SSP5-8.5,global warming will eventually exceed 5℃ by 2100,while under SSP1-2.6,it will stabilize around 2℃ after 2050.In China,most of the areas where warming exceeds global average levels will be located in Tibet and northern China(Northwest China,North China and Northeast China),covering 50%-70%of the country.Furthermore,about 0.19-0.44 billion people(accounting for 16%-41%of the national population)will experience warming above the global average.Compared to present-day(1995-2014),the warmest day(TXx)will increase most notably in northern China,while the number of warm days(TX90p)and warm spell duration indicator(WSDI)will increase most profoundly in southern China.For example,relative to the present-day,TXx will increase by 1℃-5℃ in northern China,and TX90p(WSDI)will increase by 25-150(10-80)days in southern China at 1.5℃-5℃ global warming.Compared to 2℃-5℃,limiting global warming to 1.5℃ will help avoid about 36%-87%of the EHT increases in China.     

新冠肺炎疫情对经济全球化的影响分析

新冠肺炎疫情是第二次世界大战以来世界面临的最大危机,给世界带来巨大的冲击,包括人们的心理和生活、经济增长与就业、国家治理及世界治理等。这些影响使很多学者、评论家、大众、企业家乃至政府官员产生了非常悲观的情绪,舆论中不乏经济全球化将终结、全球供应链将大规模调整、世界治理格局将彻底改变等言论。本文通过建立“全球化的三角结构”剖析了经济全球化的动力机制,并结合疫情对世界的主要影响,试图揭示后疫情时代经济全球化的走势。我们认为,资本的“空间出路”、技术的“时空压缩”和国家的开放程度是驱动经济全球化的三个基本力量,这三者的变化及其相互作用结果影响着全球化进程。从动力机制看,全球化是一个没有终点且不断变化的历史过程,它不会倒退,而是波动。过去半个世纪以来,世界各国已经被全球化紧密地联系在一起,相互脱钩的代价极其昂贵,没有国家会选择完全脱钩。所谓的逆全球化现象,是全球化发展过程中世界格局变化及各国应对策略调整的结果。新冠肺炎疫情并不能影响全球化的资本和技术驱动力,但是可能影响国家的开放程度。如果疫情持续时间不是很长,经济全球化将很快会回归原有的发展轨迹,继续进行调整。各国也将继续围绕经济全球化进行斗争、妥协、再斗争,直至形成一个相对稳定的状态。因此,经济全球化可能因为应对疫情而踩下急刹车,甚至暂退半步,但很快将继续前行,向着“包容性全球化”的方向发展。