Projections of wind changes for 21st century in China by three regional climate models

This paper examines the capability of three regional climate models(RCMs),i.e.,RegCM3(the International Centre for Theoretical Physics Regional Climate Model),PRECIS(Providing Regional Climates for Impacts Studies)and CMM5(the fifth-generation Pennsylvania State University-the National Center for Atmospheric Research of USA,NCAR Mesoscale Model)to simulate the near-surface-layer winds(10 m above surface)all over China in the late 20th century.Results suggest that like global climate models(GCMs),these RCMs have the certain capability of imitating the distribution of mean wind speed and fail to simulate the greatly weakening wind trends for the past 50 years in the country.However,RCMs especially RegCM3 have the better capability than that of GCMs to simulate the distribution and change feature of mean wind speed.In view of their merits,these RCMs were used to project the variability of near-surface-layer winds over China for the 21st century.The results show that 1)summer mean wind speed for 2020-2029 will be lower compared to those in 1990-1999 in most area of China; 2)annual and winter mean wind speed for 2081-2100 will be lower than those of 1971-1990 in the whole China; and 3)the changes of summer mean wind speed for 2081-2100 are uncertain.As a result,although climate models are absolutely necessary for projecting climate change to come,there are great uncertainties in projections,especially for wind speed,and these issues need to be further explored.     

论21世纪教育技术在教育中的作用

对教育、信息技术本质及相互之间关系的认识，有利于加深们们对21世纪教育的理解，随着教育技术的日趋完善和成熟，教育技术将在21世纪的教育中广泛使用，并将对21世纪的教育产生巨大的影响，使其在目的、内容、形式、手段方法等方面发生根本性的改变，真正实现“平等教育”和“个性化教育”等教育思想。     

Recent changes of Northern Indian Ocean summer rainfall based on CMIP5 multi-model

This study evaluates the simulation of summer rainfall changes in the Northern Indian Ocean (NIO) based on the fifth phase of Coupled Model Intercomparison Project (CMIP5). The historical runs of 20 CMIP5 coupled General Circulation Models (GCMs) are analyzed. The Multi-Model ensemble (MME) of the CMIP5 models well reproduces the general feature of NIO summer rainfall. For a short period 1979–2005, 14 out of 20 models show an increased trend in the mean rainfall and a similar spatial distribution to the Global Precipitation Climatology Project (GPCP) observations in MME. The increasing of the convergence in the equatorial IO results in the increase of rainfall significantly. The equatorial rainfall trend patterns seem modulated by the SST warming in the tropical Indian Ocean, which confirm the mechanism of ‘warmer-get-wetter’ theory. For a long period 1950–2005, the trend of monsoon rainfall over India shows a decrease over the most parts of the India except an increase over the south corn er of the Indian Peninsula, due to a weakened summer monsoon circulation. The pattern is well simulated in half of the CMIP5 models. The rainfall over the north India is different for a short period, in which rainfall increases in 1979–2005, implying possible decadal variation in the NIO summer climate.     

Wind energy input in coastal seas east of China

This study investigates the wind energy input, an important source of mechanical energy, in the coastal seas east of China. Using the wind field from the high-resolution sea surface meteorology dataset in the Bohai Sea, Yellow Sea, and East China Sea, we studied the wind energy input through surface ageostrophic currents and surface waves. Using a simple analytical formula for the Ekman Spiral with timedependent wind, the wind energy input through ageostrophic currents was estimated at ～22 GW averaged from 1960 to 2007, and through use of an empirical formula, the wind energy input through surface waves was estimated at ～169 GW. We also examined the seasonal variation and long-term tendency of mechanical energy from wind stress, and found that the wind energy input to the East China Sea decreased before the 1980s, and then subsequently increased, which is contrary to what has been found for the Bohai Sea and Yellow Sea. More complicated physical processes and varying diffusivity need to be taken into account in future studies.     

The distribution and variability of simulated chlorophyll concentration over the tropical Indian Ocean from five CMIP5 models

Performances of 5 models from the Coupled Model Intercomparison Project Phase 5 (CMIP5) in simulating the chlorophyll concentration over the tropical Indian Ocean are evaluated. Results show that these models are able to capture the dominant spatial distribution of observed chlorophyll concentration and reproduce the maximum chlorophyll concentration over the western part of the Arabian Sea, around the tip of the Indian subcontinent, and in the southeast tropical Indian Ocean. The seasonal evolution of chlorophyll concentration over these regions is also reproduced with significant amplitude diversity among models. All of 5 models is able to simulate the interannual variability of chlorophyll concentration. The maximum interannual variation occurs at the same regions where the maximum climatological chlorophyll concentration is located. Further analysis also reveals that the Indian Ocean Dipole events have great impact on chlorophyll concentration in the tropical Indian Ocean. In the general successful simulation of chlorophyll concentration, most of the CMIP5 models present higher than normal chlorophyll concentration in the eastern equatorial Indian Ocean.     

网络化教育和培训将是21世纪的重要教育方式

在即将进入 2 1世纪的今天 ,世界各国尤其是西方科技发达国家都在积极构建和提升国家信息基础 (NationalInformationInfrastructure)建设。其重要目的之一就是要适应即将来临的信息社会对教育训练的极高需求。本文将要阐述教育学习需求转变的原因 ,信息网络(web)教学的意义以及它在未来学习中将要扮演的角色 ,以及西方国家网络教育训练技术的现状与发展方向     

Interpretation of sea surface wind interannual vector EOFs over the China seas

Using interpolation and averaging methods, we analyzed the sea surface wind data obtained from December 1992 to November 2008 by the scatterometers ERS-1, ERS-2, and QuikSCAT in the area of 2°N–39 °N, 105°E–130°E, and we reported the monthly mean distributions of the sea surface wind field. A vector empirical orthogonal function (VEOF) method was employed to study the data and three temporal and spatial patterns were obtained. The first interannual VEOF accounts for 26% of the interannual variance and displays the interannual variability of the East Asian monsoon. The second interannual VEOF accounts for 21% of the variance and reflects the response of China sea winds to El Nio events. The temporal mode of VEOF-2 is in good agreement with the curve of the Nio 3.4 index with a four-month lag. The spatial mode of VEOF-2 indicates that four months after an El Nio event, the southwesterly anomalous winds over the northern South China Sea, the East China Sea, the Yellow Sea, and the Bohai Sea can weaken the prevailing winds in winter, and can strengthen the prevailing winds in summer. The third interannual VEOF accounts for 10% of the variance and also reflects the influence of the ENSO events to China Sea winds. The temporal mode of VEOF-3 is similar to the curve of the Southern Oscillation Index. The spatial mode of VEOF-3 shows that the northeasterly anomalous winds over the South China Sea and the southern part of the East China Sea can weaken the prevailing winds, and southwesterly anomalous winds over the northern part of the East China Sea, the Yellow Sea, and the Bohai Sea can strengthen the prevailing winds when El Nio occurs in winter. If El Nio happens in summer, the reverse is true.     

Interpretation of sea surface wind interannual vector EOFs over the China seas

Using interpolation and averaging methods, we analyzed the sea surface wind data obtained from December 1992 to November 2008 by the scatterometers ERS-1, ERS-2, and QuikSCAT in the area of 2°N–39 °N, 105°E–130°E, and we reported the monthly mean distributions of the sea surface wind field. A vector empirical orthogonal function (VEOF) method was employed to study the data and three temporal and spatial patterns were obtained. The first interannual VEOF accounts for 26% of the interannual variance and displays the interannual variability of the East Asian monsoon. The second interannual VEOF accounts for 21% of the variance and reflects the response of China sea winds to El Niño events. The temporal mode of VEOF-2 is in good agreement with the curve of the Niño 3.4 index with a four-month lag. The spatial mode of VEOF-2 indicates that four months after an El Niño event, the southwesterly anomalous winds over the northern South China Sea, the East China Sea, the Yellow Sea, and the Bohai Sea can weaken the prevailing winds in winter, and can strengthen the prevailing winds in summer. The third interannual VEOF accounts for 10% of the variance and also reflects the influence of the ENSO events to China Sea winds. The temporal mode of VEOF-3 is similar to the curve of the Southern Oscillation Index. The spatial mode of VEOF-3 shows that the northeasterly anomalous winds over the South China Sea and the southern part of the East China Sea can weaken the prevailing winds, and southwesterly anomalous winds over the northern part of the East China Sea, the Yellow Sea, and the Bohai Sea can strengthen the prevailing winds when El Niño occurs in winter. If El Niño happens in summer, the reverse is true.     

基于CMIP6的中国未来高温危险性变化评估

评估高温灾害的危险性变化,能够为区域高温灾害风险管理和制定减灾措施提供决策依据。本研究选取高温日数、最高温度和平均高温强度3个指标,基于1961—2020年中国2517个气象站点日最高温数据和CMIP6情景模式比较计划中SSP2-4.5情景下12个气候模式提供的2031—2099年未来气候预测数据集,用核密度概率估计方法计算了4个重现期（即5、10、20和50年）下3个指标的取值,对中国未来高温危险性变化进行了评估。结果表明：① 在SSP2.4-5情景下,中国的高温日数呈现出4个危险中心,分别是：西北干旱（半干旱）地区中部、华北和华中地区的交汇区域、西南地区中部和华南地区南部,并且高温日数从这4个中心向外逐渐减少;最高温度在空间上的分布北部大于南部,东部大于西部。平均高温强度的分布则呈现出从华北地区南部、西北干旱（半干旱）地区西部和东部地区西部向我国除青藏高原地区外的其它地区减少的趋势; ② 在SSP2.4-5情景下,随着重现期年限的增长,中国地区3个高温指标均呈增长趋势且增幅较大,并且高值范围也在不断扩大;③ 3个高温指标变化值均呈现出了明显的空间聚集性,3个指标共同显示的热点区域包括西南地区北部和南部、西北干旱（半干旱）地区中部和华北、华中地区的少部分区域,这些地区发生高温灾害的可能最大,同时根据高温日数变化和最高温度变化,东部地区西部发生高温灾害可能也较大,3个指标共同显示的冷点区域包括青藏高原地区东南部、西北干旱（半干旱）地区的西部和我国东南沿海地区,这些地区几乎不会发生高温危险。     

21世纪我国国土资源规划工作

党的“十六大”明确提出了全面建设小康社会的奋斗目标,“十六大”报告中提出的全面建设的小康社会将：经济更加发展;民主更加健全;科教更加进步;文化更加繁荣社会更加和谐;人民生活更加殷实。并且明确了全面建设中国特色社会主义经济、政治、文化各个方面的部署要求,如推进经济结构战略性调整、大力实施可持续发展战略、搞好国土资源综合整治、促进区域经济协调发展等。     

展望新世纪努力开创地矿工作新局面

明确了当前和今后一段时间地矿行政管理、地勘经济发展和科技创新工作的任务.指出:全面推进依法治矿,努力提高矿产资源规划、管理、保护和合理利用水平,加快矿业秩序根本好转的进度,加大地质灾害的防治力度;在地勘队伍属地化的基础上,加大改革调整力度,加速发展地勘经济,加快推进地勘队伍企业化的进程;大力实施科技创新,努力实现地矿科技工作的新突破.     

Relationships of interannual variability between the equatorial pacific and tropical Indian Ocean in 17 CMIP5 models

Seventeen coupled general circulation models from the Coupled Model Intercomparison Project Phase 5 (CMIP5) are employed to assess the relationships of interannual variations of sea surface temperature (SST) between the tropical Pacific (TP) and tropical Indian Ocean (TIO). The eastern/central equatorial Pacific features the strongest SST interannual variability in the models except for the model CSIRO-Mk3-6-0, and the simulated maximum and minimum are produced by models GFDL-ESM2M and GISS-E2-H respectively. However, It remains a challenge for these models to simulate the correct climate mean SST with the warm pool-cold tongue structure in the equatorial Pacific. Almost all models reproduce El Niño-Southern Oscillation (ENSO), Indian Ocean Dipole mode (IOD) and Indian Ocean Basin-wide mode (IOB) together with their seasonal phase lock features being simulated; but the relationship between the ENSO and IOD is different for different models. Consistent with the observation, an Indian Ocean basin-wide warming (cooling) takes place over the tropical Indian Ocean in the spring following an El Niño (La Niña) in almost all the models. In some models (e.g., GFDL-ESM2G and MIROC5), positive ENSO and IOB events are stronger than the negative events as shown in the observation. However, this asymmetry is reversed in some other models (e.g., HadGEM2-CC and HadGEM2-ES).     

二十一世纪城市地质工作的思考

本文阐述了城市地质工作的历史发展,着重论述了城市地质工作的内容,进而对城市地质工作的思路、方法和组织管理提出了设想。     

Impact of two typhoons on the marine environment in the Yellow Sea and East China Sea

This study investigated the ef fects of two typhoons(Nari and Wipha) on sea surface temperature(SST) and chlorophyll- a(Chl- a) concentration. Typhoons Nari and Wipha passed through the Yellow Sea on September 13, 2007 and the East China Sea(ECS) on September 16, 2007, respectively. The SST and Chl- a data were obtained from the Aqua/Terra MODIS and NOAA18, respectively, and the temperature and salinity in the southeast of the study area were observed in situ from Argo. The average SST within the study area dropped from 26.33°C on September 10 to a minimum of 22.79°C on September 16. Without the usual phenomenon of ‘right bias', the most striking response of SST was in the middle of the typhoons' tracks, near to coastal waters. Strong cooling of the upper layers of the water column was probably due to increased vertical mixing, discharge from the Changjiang River estuary, and heavy rainfall. During the typhoons, average Chl-a increased by 11.54% within the study area and by 21.69% in the off shore area near to the southeast ECS. From September 1 to 13, average Chl-a was only 0.10 mg/m~3 in the of fshore waters but it reached a peak of 0.17 mg/m~3 on September 18. This large increase in Chl-a concentration in of fshore waters might have been triggered by strong vertical mixing, upwelling induced by strong typhoons, and sedimentation and nutrient infl ux following heavy rainfall.     

Daily changes of spatial patterns of meteorological elements over Pearl River Delta based on GIS and MM5

The spatial distribution of meteorological elements is important for understanding the regional meteorology and climate changes. However, previous studies rarely focused on the daily changes of the spatial patterns of meteorological elements due to the limitation of remote sensing (RS) techniques and traditional meteorological methods. In this paper, the regional meteorological elements were simulated by the fifth-generation non-hydrostatic Mesoscale Model (MM5), and the spatial patterns of meteorological elements and their diurnal variations were analyzed in landscape level over the Pearl (Zhujiang) River Delta (PRD), China. The results showed that there were several centers of urban heat islands, cold islands, dry islands, wet islands, high wind over the PRD at noon. The diurnal changes of Moran I of meteorological elements were obvious and they reached the extremum at noon and 2-3 hours after the sunrise. The landscape indices of meteorological elements, such as area-weighted mean Fractal Dimension Index (FRAC_AM), Landscape Shape Index (LSI), Shannon's Diversity Index (SHDI) and Contagion Index (CONTAG), were more variable at about the sunrise, noon and sunset. The occurrence of wave crests and vales of landscape indices was affected by the surface net radiation, turbulence and local circumfluence. The spatial patterns of meteorological elements correlated well with the land surface, thermal exchanges and local circumfluence. A new approach combining GIS, RS and numerical simulatious technologies and the landscape ecology method was presented to analyze spatial patterns of meteorological elements, which may be useful for studying global and regional climate changes.     

21世纪世界的资源和环境

20世纪世界人口从15亿增长到60亿.而经济成长更为快速,自1950年至今已增长4倍.目前世界人口每年增加8000余万人,至2050年将达到90亿,世界经济是否能持续发展以提升或维持现有的生活水准,值得研讨.资源的消长和环境的变迁是具有决定性的两大重要议题.     

Relative sea level rise and its effects on environment and resources in China’s coastal areas

Due to global climate warming and natural and man-made land subsidence etc., relative sea level rise in the coastal plains of China will exceed 2–3 times over the golbal mean value during the first half part of the 21st century. It will result in a series of adverse impacts on evolution of natural environment and socioeconomic development of the coastal area. This paper analyses environmental and resource effects induced by relative sea level rise in China’s coastal areas on the basis of rough estimate of future relative sea level rise. These effects include inundating tidal flat and wetlands and increase in inundated risk of coastal habitable land, exacerbating storm surge. coastal erosion, flooding and salt water intrusion hazards, as well as endangering land, water, tourism and living resources and their utilization.     

Influence of reclamation works on the marine environment in a semi-enclosed bay

1Introduction GamakBay,anegg shapedseasurfaceareaofap proximately112km2,isasemi enclosedshallowwaterareawithameandepthof9mandhasbotheastandsouthchannelstoreceiveseawaterfromoutside(seeFig.1).Similarscalesoftidalwavesalmostsimultane ouslyenterorexitthrough…     

Distribution and Sources of Polycyclic Aromatic Hydrocarbon （PAH） in Marine Environment of China

1INTRODUCTIONPolycyclicaromatichydrocarbons (PAHs)depo sit edinmarineenvironmentsfromavarietyofsourcessuchaswastewater,industrialanddomesticdischarges,andoilspills.Themajorityofthesesourcesfrompetrogenicoriginischaracterizedbyadominanceoflowmolecularweightaromaticcompounds,especiallynaphthaleneandalkylatedPAHs(Sportoletal.,1 983 ) .Crudeoilanditsrefinedproductssuchasgasoline,keroseneandotherfu eloilshaveahighcontentofalkylatedPAHsduetotheirslowformationattemperatureslowerthanthatofcomb…