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Progress and review of the studies on the end-Triassic mass extinction event

Science china Earth Sciences 2005年第12期48卷 2049-2060页

作者： DENG Shenghui1,2. LU Yuanzheng1,2.3 & XU Daoyi4 1. Research Institute of Petroleum Exploration and Development, beijing 100083, china 2. Key Laboratory of Oil and Gas Reservoir of Petrochina, beijing 100083, china 3. china University of Geosciences, beijing 100083, china 4. Institute of Geology, china Earthquake administration, beijing 10002., china 1. Research Institute of Petroleum Exploration and Development 100083 Beijing China 2. Key Laboratory of Oil and Gas Reservoir of Petrochina 100083 Beijing China 3. china University of Geosciences 100083 Beijing China 4. Institute of Geology China Earthquake Administration 100029 Beijing China

The mass extinction at the end-Triassic is one of the five biggest in the Phanerozoic. However,it is the least well understood among these five events, and only till last decade it became a great academic interesting subject to geologists. The evidences for this event come obviously from bivalves, brachiopods, ammonites, corals, radiolaria, ostracods and foraminifera of marine habitats, and plants and tetrapods of terrestrial realm. By contrast, for some of other groups, such as marine gastropods and marine vertebrates, no mass extinction has been recog-nized yet. The extinction event is strongly marked at specific level but shown a complicated situa-tion at generic and family levels. Dramatic changing of the environment, such as the temperature raise due to the greenhouse effect, the marine anoxic habitats caused by a sudden transgression after the regression at the end of Triassic, has been claimed to be the main cause of the extinction. Many hypotheses have been suggested to demonstrate the mechanisms of the environment changing, among which two popular ones are the bolide impact and volcanic eruption. The Triassic-Jurassic (Tr-J) boundary mass extinction event is still poorly understood because no enough data have been obtained from the Tr-J boundary successional sections of both marine and terrestrial sediments, and most of these studies were regionally restricted. The basic aspects of the event and its associated environmental conditions remain poorly characterized and the causal mechanism or mechanisms are equivocal. Some authors even doubt its occurrence. china has many successionally developed terrestrial and marine Tr-J sections. Detailed studies of these sections may be important and significant for well understanding of the event.

关键词： progress, review, end-Triassic, mass extinction, mechanism, Tr-J boundary.

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Evaluation of a 3dVAR system for the South china Sea

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Progress in Natural Science:Materials International 2008年第5期18卷 547-554页

作者： Xianjun Xiao a,b, Dongxiao Wang a, Changxiang Yan c, Jiang Zhu c a LED, South china Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, china b NCC, {2., beijing 100081, china c Institute of Atmospheric Physics, Chinese Academy of Sciences, beijing 10002., china LED South China Sea Institute of Oceanology Chinese Academy of Sciences Guangzhou 510301 China NCC China Meteorological Administration Beijing 100081 China Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

The authors evaluate a three-dimensional variational (3dVAR) system for the South china Sea (SCS) in this study. The assimilation method applied in the system takes into consideration error correlation along each ground track and uses recursive lter for optimiza- tion. Data from three R/V cruises during the spring and summer of 1998 and the summer of 2.00 are used to evaluate the system. The root-mean-square error and bias are reduced signi cantly and when the altimeter data are assimilated, the distribution of the error is much closer to the Gaussian distribution. Precipitation and river discharge in the southwestern SCS are reproduced, and the variability of sea surface height is e ciently transferred to the subsurface. The 3dVAR system performs well for each of the three cruises, suggesting that it is steady for routine usage.

关键词： South china Sea Three-dimensional variational data assimilation Recursive lter

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Vortex genesis over the Bay of Bengal in spring and its role in the onset of the Asian Summer Monsoon

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Science china Earth Sciences 2011年第1期54卷 1-9页

作者： WU GuoXiong1, GUAN Yue1,2. WANG TongMei3, LIU YiMin1, YAN JingHui4 & MAO JiangYu1 1 State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics, Chinese Academy of Sciences, beijing 10002., china 2.raduate University of Chinese Academy of Sciences, beijing 100049, china 3Department of Atmospheric Science, Sun Yat-Sen University, Guangzhou 5102.5, china 4national Climate Center, china meteorological administration, beijing 100080, china 1. State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG) Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China3. Department of Atmospheric Science Sun Yat-Sen University Guangzhou 510275 China4. National Climate Center China Meteorological Administration Beijing 100080 China

Physical processes associated with onset of the 1998 Asian summer monsoon were examined in detail using multi-source datasets. We demonstrated that strong ocean-atmosphere-land interaction in the northern Indian Ocean and tropical Asian area during spring is a fundamental factor that induces the genesis and development of a monsoon onset vortex over the Bay of Bengal (BOB), with the vortex in turn triggering onset of the Asian summer monsoon. In spring, strong surface sensible heating over India and the Indochina Peninsula is transferred to the atmosphere, forming prominent in situ cyclonic circulation, with anticyclonic circulations over the Arabian Sea and northern BOB where the ocean receives abundant solar radiation. The corresponding surface winds along the North Indian Ocean coastal areas cause the ocean to produce the in situ offshore currents and upwelling, resulting in sea surface temperature (SST) cooling. With precipitation on the Indochina Peninsula increasing from late April to early May, the offshore current disappears in the eastern BOB or develops into an onshore current, leading to SST increasing. A southwest-northeast oriented spring BOB warm pool with SST >31°C forms in a band from the southeastern Arabian Sea to the eastern BOB. In early May, the Somali cross-equatorial flow forms due to the meridional SST gradient between the two hemispheres, and surface sensible heat over the African land surface. The Somali flow overlaps in phase with the anticyclone over the northern Arabian Sea in the course of its inertial fluctuation along the equator. The convergent cold northerlies on the eastern side of the anticyclone cause the westerly in the inertial trough to increase rapidly, so that enhanced sensible heat is released from the sea surface into the atmosphere. The cyclonic vorticity forced by such sensible heating is superimposed on the inertial trough, leading to its further increase in vorticity strength. Since atmospheric inertial motion is destr

关键词： air-sea interaction spring BOB warm pool monsoon onset vortex inertial oscillation Asian summer monsoon onset

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Water-vapor source shift of Xinjiang region during the recent twenty years

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Progress in Natural Science:Materials International 2007年第5期17卷 569-575页

作者： Dai Xingang , Li Weijing , Ma Zhuguo and Wang Ping (Key Laboratory of Regional Climate-Environment for Temperate East Asia, Institute of Atmospheric Physics, Chinese Academy of Sciences, beijing 10002., china Laboratory for Climate Change, Chinese {2. administration, beijing 100081, china) [a]Key Laboratory of Regional Climate-Environment for Temperate East Asia Institute of Atmospheric PhysicsChinese Academy of Sciences Beijing China [b]Laboratory for Climate Change Chinese meteorological administration Beijing China

The aim of this paper is to investigate the climate water-vapor sources of Xinjiang region and their shifts during the past 2. years. First, the principle and steps are roughly regulated to seek the water-vapor sources. Second, the climate stationary water-vapor transport in troposphere is calculated to distinguish where the water vapor comes from by ERA-40 reanalysis. In addition, the collocation between the transport and the atmospheric column water vapor content is analyzed. The results show that the major vapor comes from the west side of Xinjiang for mid-month of seasons, apart from July while the water vapor comes from the north or northwest direction. The water vapor sources are different for different seasons, for example, the Caspian Sea and Mediterranean are the sources in January and April, the North Atlantic and the Arctic sea in July, and the Black Sea and Caspian Sea in October, respectively. In recent ten years more water vapor above Xinjiang comes from the high latitudes and the Arctic sea with global warming, and less from Mediterranean in comparison with the case of 1973—1986. In fact, the air over subtropics becomes dry and the anomalous water vapor transport direction turns to west or southwest during 1987—2.00. By contrast, the air over middle and high latitudes is warmer and wetter than 14 years ago.

关键词： global warming water-vapor source water-vapor transport precipitable water Xinjiang climate inter-decadal change.

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umerical tests of efficiency of the retrospective time integration scheme in the self-memory model

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Progress in Natural Science:Materials International 2004年第9期 89-92页

作者： GU Xiangqian 1*, YOU Xingtian 2. ZHU He 2.and CAO Hongxing 1(1. Chinese Academy of meteorological Sciences, beijing 100081, {2. 2. Training Center of china meteorological administration, beijing 100081, {2.)

A set of numerical tests was carried out to compare the retrospective time integral scheme in a self memory model, whose dynamic kernel is the barotropical quasi geostrophic model, with the ordinary centered difference scheme in the barotropical quasi geostrophic model. The Rossby Haurwitz wave function was taken as the initial fields for both schemes. The results show that in comparison with the ordinary centered difference scheme, the retrospective time integral scheme reduces by 2.orders of magnitude the forecast error, and the forecast error increases very little with lengthening of the time step. Therefore, the retrospective time integral scheme has advantages of improving the forecast accuracy, extending the predictable duration and reducing the computation amount.

关键词： numerical tests self-memory model retrospective time integral scheme.

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Size-dependent hydroxyl radicals generation induced by SiO_2.ultra-fine particles: The role of surface iron

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Science china Chemistry 2009年第7期52卷 1033-1041页

作者： SHANG Yu1, ZHU Tong1, LI Yi1,2.& ZHAO JinCai3 1 College of Environmental Sciences and Engineering, Peking University, beijing 100871, china 2.Chinese Academy of {2. Sciences, beijing 100871, china 3 Institute of Chemistry, Chinese Academy of Sciences, beijing 100871, china 1. College of Environmental Sciences and Engineering Peking University Beijing 100871 China 2. Chinese Academy of meteorological Sciences Beijing 100871 China 3. Institute of Chemistry Chinese Academy of Sciences Beijing 100871 China

Oxidative stress and hydroxyl radicals (·OH) play important roles in adverse health effects caused by inhalable ambient air particles (PM10). The ultra-fine fraction of PM10 has been hypothesized as one of the critical contributors to ·OH generation. Both in vivo and in vitro studies have shown that ultra-fine particles (UFPs) or nano-particles generate more ·OH than larger particles with identical mass and composition. Both the surface area and surface-adsorbed redox-active metals have been suggested as factors to determine the oxidative capacity of UFPs. In this study, the ·OH-generating capability of dif-ferent sizes of SiO2.particles was investigated in order to determine which factor influences particle-induced ·OH generation. The amount of ·OH generated in both acellular and cellular systems was quantified using a capillary electrophoresis method following exposure to SiO2.particles with diameters of 14, 100, and 500 nm. The amount of ·OH was strongly dependent on particle size, and a significant enhancement was observed only with 14 nm particles. Further studies indicated a close association between ·OH and iron ion concentration (R2.= 0.812. p2.particles is presented as a possible mechanism of UPFs-induced ·OH generation. The SiO2.acted as an inert substrate, and the surface of ultra-fine SiO2.particles acted as a carrier for iron.

关键词： ultra-fine particles nano-particles ·OH oxidative stress size-effect

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PRESIDENT JIANG ZEMING CARES FOR THE meteorological UNDERTAKING

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Natural Disaster Reduction in china 1996年第2期 49-50页

作者： Xue Zhifen(china meteorological administration, beijing 100081 )

ＰＲＥＳＩＤＥＮＴＪＩＡＮＧＺＥＭＩＮＧＣＡＲＥＳＦＯＲＴＨＥＭＥＴＥＯＲＯＬＯＧＩＣＡＬＵＮＤＥＲＴＡＫＩＮＧＸｕｅＺｈｉｆｅｎ（ＣｈｉｎａＭｅｔｅｏｒｏｌｏｇｉｃａｌＡｄｍｉｎｉｓｔｒａｔｉｏｎ，Ｂｅｉｊｉｎｇ１... 详细信息

ＰＲＥＳＩＤＥＮＴＪＩＡＮＧＺＥＭＩＮＧＣＡＲＥＳＦＯＲＴＨＥＭＥＴＥＯＲＯＬＯＧＩＣＡＬＵＮＤＥＲＴＡＫＩＮＧＸｕｅＺｈｉｆｅｎ（ＣｈｉｎａＭｅｔｅｏｒｏｌｏｇｉｃａｌＡｄｍｉｎｉｓｔｒａｔｉｏｎ，Ｂｅｉｊｉｎｇ１０００８１）ＩｎＪａｎｕａｒｙ１７...

关键词： JIANG

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Semi-analytical analysis of the response of the air temperature over the land surface to the global vegetation distribution

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Chinese Science Bulletin 2009年第14期54卷 2499-2505页

作者： LIU Fei1,2.& CHAO JiPing3,4 1 Institute of Atmospheric Physics, Chinese Academy of Sciences, beijing 10002., china 2.Graduate University of Chinese Academy of Sciences, beijing 100049, china 3 national Marine Environmental Forecasting Center, beijing 100081, china 4 First Institute of Oceanography, State Oceanic administration of china, Qingdao 2.6061, china Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Graduate University of Chinese Academy of Sciences Beijing 100049 China national Marine Environmental Forecasting Center Beijing 100081 China First Institute of Oceanography State Oceanic Administration of China Qingdao 266061 China

Response of the air temperature over the land surface to the global vegetation distribution is investigated, using a three-dimensional governing equation to simulate the steady, large-scale, limited amplitude perturbation of the free, inviscid and adiabatic atmosphere. The adoption of the static equation leads to a temperature governing equation in the terrain following coordinate. With the prescribed temperature as the upper boundary condition and the radiation balance as the lower boundary condition, the semi-analytical solution of the global circulation temperature can be calculated. In this article, only the air temperature (at 2.m height) over the land surface is analyzed, and the result suggests that this model can simulate the air temperature pattern over the land surface reasonably. A better simulation occurs when a simple feedback of the albedo on the temperature is included. Two sensitivity experiments are analyzed through this model. One suggests that the air temperature over the land surface descends obviously when the land surface is covered with ice all over, while another suggests that the air temperature rises a little when the land surface is covered with forest except the ice-covered area. This model appears to be a good tool to study the response of the air temperature to the vegetation distribution. Limitations of the model are also discussed.

关键词：空气温度植被分布陆地表面反应解析分析模拟模式控制方程边界条件

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High-resolution Rayleigh wave phase velocity maps from ambient noise tomography in North china

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Earthquake Science 2012年第3期25卷 241-251页

作者： Jiatie Pan Institute of Geophysics, china Earthquake administration, {2., china 1. Institute of Geophysics China Earthquake Administration Beijing 100081 China

We presented high-resolution Rayleigh wave phase velocity maps at periods ranging from 5 s to 30 s in the northeast part of the North china Craton (NNCC). Continuous time-series of vertical component between October 2.06 and December 2.08, recorded by 187 broadband stations temporarily deployed in the NNCC region, have been cross-correlated to obtain estimated fundamental mode Rayleigh wave Green’s functions. Using the frequency and time analysis technique based on continuous wavelet transformation, we measured 3 667 Rayleigh wave phase velocity dispersion curves. High-resolution phase velocity maps at periods of 5, 10, 2. and 30 s were reconstructed with grid size 0.2.°× 0.2.°, which reveal lateral heterogeneity of shear wave structure in the crust and upper mantle of NNCC. For periods shorter than 10 s, the phase velocity variations are well correlated with the principal geological units in the NNCC, with low-speed anomalies corresponding to the major sedimentary basins and high-speed anomalies coinciding with the main mountain ranges. Within the period range from 2. s to 30 s, high phase velocity observed in eastern NCC is coincident with the thin crust, whereas low phase velocities imaged in central NCC is correlated to the thick crust. However, the low-velocity anomaly in the beijing-Tianjin-Tangshan region displayed in the 2. s and 30 s phase maps may be associated with fluids.

关键词： Rayleigh wave phase velocity ambient noise tomography wavelet transformation North china Craton

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An improvement on summer regional climate simulation over East china: Importance of data assimilation of soil moisture

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Chinese Science Bulletin 2010年第9期55卷 867-873页

作者： HU YaMin1,2.3, DING YiHui4 & LIAO Fei2.1 Institute of Tropical and Marine Meteorology, china meteorological administration, Guangzhou 510080, china 2.Guangdong Climate Center, Guangzhou 510080, china 3 Chinese Academy of meteorological Sciences, beijing 100081, china 4 national Climate Center, china meteorological administration, beijing 100081, china

The Newtonian relaxation is used to assimilate data from the Second Global Soil Wetness Project (GSWP2. into the initial field for soil moisture in a regional climate model (i.e., BCC_RegCM 1.0, hereinafter called RegCM). The results show that different nudging parameters can improve the simulation of the air temperature and the precipitation to some extent in summertime season over East china. When the nudging intensity is 0.5 and nudging duration is 5 days, the result is desirable. Introducing the data assimilation of soil moisture into RegCM, the amelioration is not only in the spatial distribution pattern but also in the magnitude of the temperature and the precipitation. More specifically, the assimilation experiments have corrected the systematical cold bias of the air temperature and the precipitation on the low side, which is much closer to the observation compared with the control experiment. On the whole, the assimilation experiments shed light on the fact that the simulated bias in the original RegCM may be affected by the description of soil moisture in the land surface process. Therefore, the effect of soil moisture in RegCM should be paid more attention in the future.

关键词： soil moisture Newtonian relaxation data assimilation regional climate simulation

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