Research on the Global Warming Hiatus

A global warming “hiatus” has been observed since the beginning of the 21st century despite the increase in heat-trapping greenhouse gases, challenging the current global warming studies. Focusing on the phenomena and mechanisms of the global warming “hiatus”, the National Key Research Program of China launched a project in July, 2016. The main research themes of this project cover: ①Revealing the spatial and temporal variability of the global warming hiatus, and quantifying the contributions of external forcing and internal (natural) variability, respectively; ②Revealing the role of the atmosphere in the global heat and energy redistribution under global warming hiatus; ③Revealing the role of the ocean in the global heat and energy redistribution under global warming hiatus; ④Investigating the predictability of the global warming hiatus. The key scientific issues to be resolved include: ①Identifying characteristics of the global warming hiatus and discerning the roles of decadal, multi-decadal oscillations; ②Revealing the role of ocean-atmosphere dynamical processes in the global redistribution of heat and energy; ③Understanding the predictability of the global warming hiatus. The research aims to predict the future development of the global warming hiatus, and to point out the possible impacts on China and other important areas, including “The Belt and Road” core area and the Polar Regions.     

Some aspects of export labour service in China

This paper focuses on the evolution and characteristics of the export labour service in China since the modern time especially since the reform of economic system in 1978. Historically the contract workers, central to the goal of making a living, were the main body of the international migration. And Guangdong and Fujian provinces were the main origin places of the migration but the destination of the migrants varied. Both pull and push forces for driving the migration were identified. Then analysis is turned to the characteristics of export labour service of China since the reform of economic system in 1978. 1) The export labour has increased rapidly despite a small quantity. 2) The export labour service is planned and organized. 3) The export workers are considered temporary migrants. 4) The dominant ways of export labour service are project contracts and pure labour export. And 5) the destinations of export labour are scattered over the world. Thirdly, the impact of the export labour service on the origin places and the emerging problems and contradictions were examined. In China, export labour service has alleviated the employment contradiction and gradually become one of sources of gaining foreign currency on the one hand, and China, through the service, has learnt the advanced technology and management experiences of other countries. However, some problems in the service such as small number, unsatisfactory quality of the export labour, and the weak link between the service and employment are emerging, which need to be solved. Finally, the prospects for China as a large country of export labour was discussed.     

An Amplification Mechanism of Intraseasonal Long Rossby Wave in Subtropical Ocean

The satellite altimeter data reveal that intraseasonal long Rossby wave is amplified in the western part of subtropical ocean. Based on a two and half layer ocean model we infer that the intraseasonal long Rossby wave may be amplified by the baroclinic instability. According to the baroclinic instability criterion derived from the two and half layer model, we calculate the baroclinic instability area of the Subtropical North Pacific Ocean based on Levitus98 data. The baroclinic instability area is well in accord with the amplification area of the intraseasonal long Rossby wave, and this also proves that the baroclinic instability is the main amplification mechanism of the intraseasonal long Rossby wave in the subtropical ocean. The consistency between the baroclinic instability area and potential vorticity (PV) pool is further proved in this paper, therefore, we have confidence that the intraseasonal long Rossby wave is amplified in the PV pool. Due to the relatively large ocean basin and weak ventilation, the PV pool is much larger in the North Pacific Ocean than in the North Atlantic Ocean, and this is the reason for the difference of wave amplification areas of these two Oceans.     

东海黑潮混沌特征的数值分析

以英国 OCCAM(The Ocean Circulation and Climate Advanced Modeling Project)全球环流模式的 1 994年计算结果作为初始场和边界条件 ,用 POM模式 ,对东中国海黑潮季节变化进行了数值模拟 ,特别注意了海水运动的混沌特点和质点移动轨迹。研究结果表明 :东海黑潮区地形引起的黑潮流剪切是导致混沌的主要原因 ;东海黑潮区混沌运动有明显的季节变化 ;黑潮主轴区基本是输运的屏障区。     

广州市零售商业中心消费活动时变模式及其影响因素

利用2016年在广州典型大型零售商业中心进行的客流量监测和居民消费行为问卷数据,分析基于客流时间变化的广州大型零售商业中心消费活动时变模式,构建多项Logistic回归模型,从消费者社会经济属性、消费活动特征和商业中心建成环境3方面探讨该时变模式的影响因素。结果显示：① 广州不同的大型零售商业中心内消费活动存在明显的时变特征差异,可分成稳定型、下午高峰型、傍晚高峰型和不规则波动型4类时变模式;② 这种时变模式受到消费者社会经济属性、消费活动特征和商业建成环境等变量的影响。其中,消费者社会经济属性和消费活动特征影响有限且影响差异较大,以稳定型为参照组,在广州居住时间、居住区位和家庭月收入等社会经济属性,以及消费结构、出行路径、交通方式和出行距离等消费活动特征能区分稳定型和下午高峰型商业中心,但只有在广州居住时间和出行距离、交通方式3个变量能显著地解释稳定型和傍晚高峰型商业中心的差异;建成环境是影响零售商业中心时变模式的首要因素,商业网点密度、用地混合度、公交与地铁站点密度、商业中心区位特征、到市中心距离等变量均对各个类型商业中心的形成作用显著。期望为城市零售商业中心的分类和评价提供一个新思路,为预测商业中心可能的消费活动时变模式、消费者属性和活动特征提供理论依据,对城市商业规划和商业中心开发运营有一定的现实指导意义。     

Ore-controllingRegularitiesof Structureinthe LehongLead-zinc Deposit, Northeastern Yunnan

<正>1 Introduction The Lehonglead-zincdeposit is a large-sized Pb-Zn depositnewly found in recent years in the Sichuan-Yunnan-Guizhou Lead-zinc Poly-metallic Mineralization Area,which occurrenceis strictly     

Statistical analyses of sea state conditions in South China Sea

The statistical characterization of sea conditions in the South China Sea(SCS) was investigated by analyzing a 30-year(1976–2005) numerically simulated daily wave height and wind speed data. The monthly variation of these parameters shows that wave height and wind speed have minimum values of 0.54 m and 4.15 ms~(-1), respectively in May and peak values of 2.04 m and 8.12 ms~(-1), respectively in December. Statistical analysis of the daily wave height and wind speed and the subsequent characterization of the annual, seasonal and monthly mean sea state based on these parameters were also done. Results showed that, in general, the slight sea state prevails in the SCS and has nearly the highest occurrence in all seasons and months. The moderate sea condition prevails in the winter months of December and January while the smooth(wavelets) sea state prevails in May. Furthermore, spatial variation of sea states showed that calm and smooth sea conditions have high occurrences(25%–80%) in the southern SCS. The slight sea condition shows the largest occurrence(25%–55%) over most parts of the SCS. High occurrences(8%–17%) of the rough and very rough seas distribute over some regions in the central SCS. Sea states from high to phenomenal conditions show rare occurrence(12%) in the northern SCS. The calm(glassy) sea condition shows no occurrence in the SCS.     

河西走廊入口区下垫面对沙尘天气影响的模拟研究

在利用常规观测资料统计分析2000—2011年和沙尘天气多发年河西走廊入口区代表站点春季风速分布特征的基础上,采用区域气候模式（Regcm4.3.5.6）和欧洲中心更新的4DVar同化的ERA-interim资料,分析了河西走廊入口区下垫面类型改变对2007年4月13日一次沙尘天气过程的影响。结果表明：沙尘暴爆发时,河西走廊为风速大值区,风速8～10 m·s^-1;区域气候模式模拟的沙尘特征量与站点观测的沙尘天气分布对比发现,模拟的沙尘区的发展变化能较好地表征这次沙尘天气过程的变化;河西走廊入口区植被由沙漠改为落叶阔叶林后,发生沙尘天气时该地区风速有所减小,减小平均值为3 m·s^-1,且风速越大,减小越明显。不同粒径沙尘的起沙率和沙尘粒子柱含量对下垫面类型改变的响应有所不同,减小量最大分别达到-50 mg·m^-2·d^-1和-50 mg·m^-2,0.01～5.0 μm粒径沙尘减小范围和强度相差不大,5.0～20 μm粒径沙尘由于粒径最大减小最明显,由于模式中考虑的2.5～5.0 μm粒径沙尘在大气中所占比例小,减小量级和范围最弱。改变下垫面类型使得起沙率和沙尘粒子柱含量在沙尘天气最强时刻减少最显著。     

Application of shallow high-resolution transient electromagnetic method( TEM) in geological investigation of debris flow

In the investigation of debris flow, the detection of the source area of the post-disaster debris flow is an important basis for evaluating the distribution of the debris flow accumulation layer and the subsequent control. In this paper, a shallow high-resolution TEM is used to detect the debris flow source area in Dashigou village, Yongji County, Jilin Province. The purpose of this investigation is to determine the depth range of debris flow damage. The detection results show that there is an obvious low resistance zone at about 10 m depth along the survey line, which is in good agreement with the drilling data and the high density electrical detection. It is proved that the depth is the maximum impact depth of the debris flow. The practical engineering proves that the method has high resolution in shallow layer detection, high efficiency and convenience in field acquisition. The maximum detection depth range of this method is 30--40 m, which meets the requirements of high efficiency and accurate detection for regional debris flow source area, and has high practical application value.     

Quantifying the non-conservative production of potential temperature over the past 22000 years

The energy budgets of the ocean play a crucial role in the analysis of climate change. Potential temperature is traditionally used as a conservative quantity to express variations associated with "heat"in oceanography, such as the heat content and heat transport. However, potential temperature is usually not conserved during turbulent mixing, so the use of conservative temperature is more accurate. Based on climatological simulations under the modern and Last Glacial Maximum(LGM; ～21 ka; ka=thousand years ago), as well as a transient climate simulation of the past 22 000 years, we quantify the errors induced by the neglect of the non-conservation of potential temperature in paleo-climate research for the first time. The temperature error reaches 0.9°C near the coasts af fected by river discharges but is much smaller in the open oceans, typically 0.03°C above the main thermocline and less than 0.01°C elsewhere. The error of the ocean heat content(OHC) is roughly 3×10 22 J and is relatively steady over the past 22 000 years. However, the OHC increases to six times the original value during the last glacial termination from 20 ka to 7 ka. As a result, the relative OHC error decreases from 1.2% in the LGM climate to 0.14% in the modern climate. The error of the ocean meridional heat transport(OMHT) is generally smaller than 0.005 PW(1 PW=10 15 W),with very small temporal variations(typically 0.000 4 PW), and induces a relative OMHT error of typically0.3% over the past 22 000 years. Therefore, the neglect of the non-conservation of potential temperature induces a relative error of generally less than 1% in the analyses of basin-scale climate variations.