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Progress in China’s climate change study in the 2.th century

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Journal of Geographical Sciences 2004年第S1期 5-13页

作者： ZHAI Panmao1,2. CHAO Qingchen1,2. ZOU Xukai1,2.1. laboratory for climate{2., China meteorological administration, beijing 100081, China 2. National climate Center, China meteorological administration, beijing 100081, China)

studies on the 2.th century climate change in China have revealed that under the background of global warming over the past century, climate in China has also experienced significant change with mean annual temperature increased by about 0.5 oC. More reliable results for the latter part of the 2.th century indicate that the largest warming occurred in Northwest China, North China and Northeast China, and the warming in winter is most significant. Although no obvious increase or decrease trends were detected for mean precipitation over China in the past half century, regional differences are very distinct. In the middle and lower reaches of the Yangtze River, precipitation increased, while that in the Yellow River Basin markedly decreased. studies suggest that climate change in China seems to be related not only with the internal factors such as ENSO, PDO, and the others, but also with the anthropogenic effects such as greenhouse gas emissions, and land use. The future climate change studies in China seem to be important in narrowing understanding the nature of China's climate change and its main causes, since it is significant for projection and for impact assessment of climate change in the future.

关键词： th century climate change China

Possible mechanism of the effect of convection over Asian-Australian “land bridge” on the East Asian summer monsoon onset

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Science China Earth Sciences 2006年第11期49卷 1223-1232页

作者： HE Jinhai1, WEN Min2. DING Yihui3 & ZHANG Renhe2.1. Jiangsu Key laboratory of meteorological Disaster (KLME), Nanjing Institute of Meteorology, Nanjing University of Informa- tion Science and Technology, Nanjing 2.0044, China 2. State Key laboratory of Severe Weather (LaSW), Chinese Academy of meteorological Sciences, beijing 100081, China 3. National climate Center, Chinese meteorological administration, beijing 100081, China Jiangsu Key laboratory of meteorological Disaster (KLME) Nanjing Institute of Meteorology Nanjing University of Information Science and Technology Nanjing China State Key laboratory of Severe Weather (LaSW) Chinese Academy of Meteorological Sciences Beijing China National climate Center Chinese Meteorological Administration Beijing China

The Asian-Australian “land bridge” is an area with the most vigorous convection in Asian monsoon region in boreal spring, where the onset and march of convection are well associated with the onset of East Asian summer monsoon. The convection occurs over Indo-China Peninsula as early as mid-April, which exerts critical impact on the evolution of monsoon circulation. Before mid-April there are primarily sensible heatings to the atmosphere over Indo-China Peninsula and Indian Peninsula, so the apparent heating ratios over them decrease with height. However, after mid-April it changes into latent heating over Indo-China Peninsula due to the onset of convection, and the apparent heating ratio increases with height in mid- and lower troposphere. The vertical distribution of heating ratio and its differences between Indo-China Peninsula and Indian Peninsula are the key factors leading to the splitting of boreal subtropical high belt over the Bay of Bengal. Such mechanism is strongly supported by the fact that the evolution of the vertical heating ratio gradient above Indo-China Peninsula leads that of 850 hPa vorticity over the Bay of Bengal. Convections over Indo-China Peninsula and its surrounding areas further increase after the splitting. Since then, there is a positive feedback lying among the convective heating, the eastward retreat of the subtropical high and the march of monsoon, which is a possible mechanism of the advance of summer monsoon and convection from Indo-China Peninsula to South China Sea.

关键词： Asian-Australian 'land bridge', tropical convection, Indo-China Peninsula, the splitting of boreal subtropical high belt, East Asian summer monsoon onset.

Predictor-based error correction method in short-term climate prediction

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Progress in Natural Science:Materials International 2008年第1期18卷 129-135页

作者： Hongli Ren laboratory for climate{2.,National climate Center,China meteorological administration,beijing 100081,China laboratory for climate{2. National Climate Center China Meteorological Administration Beijing 100081 China

In terms of the basic idea of combining dynamical and statistical methods in short-term climate prediction,a new prediction method of predictor-based error correction(PREC)is put forward in order to effectively use statistical experiences in dynamical ***- yses show that the PREC can reasonably utilize the significant correlations between predictors and model prediction errors and correct prediction errors by establishing statistical prediction ***,the PREC is further applied to the cross-validation experiments of dynamical seasonal prediction on the operational atmosphere-ocean coupled general circulation model of China meteorological Admin- istration/National climate Center by selecting the sea surface temperature index in Ninflo3 region as the physical predictor that represents the prevailing ENSO-cycle mode of interannual variability in climate *** is shown from the prediction results of summer mean circulation and total precipitation that the PREC can improve predictive skills to some *** the PREC provides a new approach for improving short-term climate prediction.

关键词： Short-term climate prediction Seasonal prediction Predictor Error correction

Debating about the climate warming

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Progress in Natural Science:Materials International 2006年第1期16卷 1-6页

作者： WANG Shaowu1, LUO Yong2. ZHAO Zongci2. DONG Wenje2.and YANG Bao3 (1.Department of Atmospheric Sciences, School of Physics, Peking University, beijing 100871, China 2. laboratory for climate studies, China{2. administration, beijing 100081, China 3. Institute of Cold and Arid Regions Environmental and Engineering, Chinese Academy of Sciences, Lanzhou 730000, China) Department of Atmospheric Sciences School of Physics Peking University Beijing 100871 China laboratory for climate{2. China Meteorological Administration Beijing 100081 China Institute of Cold and Arid Regions Environmental and Engineering Chinese Academy of Sciences Lanzhou 730000 China

Debating about the climate warming is reviewed. Discussions have focused on the validity of the temperature reconstruction for the last millennium made by Mann et al. Arguments against and for the reconstruction are introduced. Temperature reconstructions by other authors are examined, including the one carried out by Wang et al. in 1996. It is concluded that: (1) Ability of reproducing temperature variability of time scale less than 10 a is limited, so no sufficient evidence proves that the 1990s was the warmest decade, and 1998 was the warmest year over the last millennium. (2. All of the temperature reconstructions by different authors demonstrate the occurrence of the MWP (Medieval Warm Period) and LIA (Little Ice Age) in low frequency band of temperature variations, though the peak in the MWP and trough in LIA varies from one reconstruction to the others. Therefore, terms of MWP and LIA can be used in studies of climate change. (3) The warming from 1975 to 2.00 was significant, but we do not know if it was the strongest for the last millennium, which needs to be proved by more evidence.

关键词： climate warming MWP LIA the 2.th century.

Sea-salt aerosol transport patterns over the Northern Hemisphere inferred from two subarctic ice core records

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Science China Earth Sciences 2005年第4期48卷 576-584页

作者： YAN Yuping1,2. KANG Shichang2.3,5, SUN Junying4,5, Paul A. Mayewski2.& QIN Dahe5 1. National climate Center, China meteorological{2., beijing 100081, China 2. climate Change Institute, University of Maine, Orono, ME 04469, USA 3. Institute of Tibetan Plateau Research, Chinese Academy of Sciences, beijing 100085, China 4. Chinese Academy of meteorological Sciences, beijing 100081, China 5. Key laboratory of Ice Core and Cold Regions Environment, Cold and Arid Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China National climate Center China Meteorological Administration Beijing China climate Change Institute University of Maine Orono ME USA Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing China Key laboratory of Ice Core and Cold Regions Environment Cold and Arid Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou China Chinese Academy of meteorological Sciences Beijing China

Atmospheric circulation reconstruction based on glaciochemical records requires knowledge of chemical concentration controls, such as source, transport pathway and strength. To gain insight into these processes, the relationships between glaciochemical records from two Northern Hemisphere sites (Mt. Logan in Yukon Territory and 2.D in southern Greenland) and instrumental sea level pressure (SLP) series are investigated. Calibrations between Mt. Logan sea-salt sodium (ssNa+) concentration and SLP series show that ssNa+ concentrations are closely correlated with the autumntime (SON) Aleutian Low and the summertime (JJA) North Pacific Subtropical High. Both the deepened Aleutian Low and enhanced North Pacific Sub- tropical High strengthen the transport of sea-salt aerosols from the North Pacific to the Mt. Logan region. Calibrations between 2.D ssNa+ concentrations and SLP series indicate that ssNa+ concentrations are closely related to the wintertime (Jan.) Icelandic Low. A deepening of the Icelandic Low strengthens winter storms and frequent cyclogenesis over the North Atlantic and pushes more sea-salt laden air masses to the Greenland ice sheet. Therefore, ice core ssNa+ records from the Mt. Logan region can be considered as a proxy for reconstructing the au- tumntime Aleutian Low and summertime North Pacific Subtropical High, and the ssNa+ records from Greenland ice core (2.D) may provide a proxy for reconstructing the wintertime Icelandic Low.

关键词： sea-salt aerosol, ice core records, sea level pressure, subarctic regions.

Virtual ChuanDian--A parallel numerical modeling of Sichuan-Yunnan regional strong earthquake activities: Model construction and parallel simulation

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Science China Earth Sciences 2009年第10期52卷 1585-1598页

作者： ZHANG Huai1, WU ZhongLiang1,2. ZHANG DongNing2. LIU Jie2. WANG Hui2. YAN ZhenZhen1,2.& SHI YaoLin11 laboratory of Computational Geodynamics, Graduate University of Chinese Academy of Sciences, beijing 100049, China 2.Institute of Geophysics, Chinese Earthquake{2., beijing 100081, China laboratory of Computational Geodynamics Graduate University of Chinese Academy of Sciences Beijing China Institute of Geophysics Chinese Earthquake Administration Beijing China

Reasonable use of mathematical modeling and numerical simulation of regional earthquake activities has attracted more and more attentions in realistic seismicity studies in recent years. The inherent nature of their attendant multi-scale properties, from either the temporal or the spatial direction, necessitates the use of the cutting-edge massive parallel data processing techniques. Our study here is focused on the model construction and numerical simulation of the regional stress evolution after large earthquake sequences along the fault zones in Sichuan and Yunnan areas, using large-scale parallel finite element approximations with tens of millions of unstructured meshes on the distributed systems. The objective of our study is to provide a state-of-the-art model and a large-scale numerical simulation platform, on which estimation of the risk of large earthquake triggering sequences can be carried out in a middle or long-term time scale with realistic data and constrains inputted from field observation and geological survey.

关键词： Sichuan-Yunan area seismic processing parallel simulation initial stress field

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

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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 Research Institute of Petroleum Exploration and Development Beijing China Key laboratory of Oil and Gas Reservoir of PetroChina Beijing China China University of Geosciences Beijing China Institute of Geology China Earthquake Administration 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.

Anatexis in Himalayan crust:Evidence from geochemical and chronological investigations of Higher Himalayan Crystallines

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Science China Earth Sciences 2005年第9期48卷 1347-1356页

作者： YANG Xiaosong1, JIN Zhenmin2.& MA Jin1 1. State Key laboratory of Earthquake Dynamics, Institute of Geology, China Earthquake administration,{2. 10002., China 2. Faculty of Earth Sciences, China University of Geosciences, Wuhan 430074, China State Key laboratory of Earthquake Dynamics Institute of Geology China Earthquake Administration Beijing China Faculty of Earth Sciences China University of Geosciences Wuhan China

Migmatization in Higher Himalayan Crystallines (HHC) results from anatexis. The widely distributed migmatites in HHC are an important clue to investigate the relationship be- tween anatexis and the origins of Higher Himalayan leucogranites (HHL), and to understand the effect of anatexis on crustal evolution during the post-collision period. We studied in detail the chemical features of three basic constituent parts of the migmatites, i.e. leucosome, mesosome and melanosome, and determined the K-Ar ages of leucosomes. Our studies indicate that type-I leucosome is the product of crystallization of melt generated by partial melting of mesosome at source region, but type-II leucosome and HHL probably underwent crystallization differentiation of plagioclase during melt aggregation and migration. The age of 2..67 Ma of Type-I leucosome, which is a little older than the beginning of MCT movement, indicates that anatexis may have played an important role in the formation of MCT. That the ages of type-II leucosome (ranging from 14.82.to 18.37 Ma) are consistent with that of HHL provides new chronological evidence for the relationship between migmatization and HHL. We obtained a very young age of 6.2. Ma of Type-II leucosome that provides new time constraint on magma activity in the central segment of Higher Himalayas.

关键词： Higher Himalayan Crystallines, migmatite, anatexis, leucosome, K-Ar age.

Some characteristics of the atmosphere during an adiabatic process

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Progress in Natural Science:Materials International 2006年第6期16卷 644-648页

作者： GAO Li, LI Jianping and REN Hongli (LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences, beijing 10002., China Graduate School of Chinese Academy of Sciences, beijing 100049, China National{2. Center, laboratory of{2. studies, China meteorological administration, beijing 100081, China) LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Graduate School of Chinese Academy of Sciences Beijing 100049 China National climate Center Laboratory of Climatic Studies China Meterological Administration Beijing 100081 China

Some important characteristics of the atmosphere during an adiabatic process are investigated, which include the invariability of atmospheric entropy range and local surface potential temperature, the conservation of the atmospheric mass intervened between any isentropic surface and the ground, and the isentropic surface intersecting with the ground. The analysis shows that the atmospheric reference state (ARS) for investigation on available potential energy (APE) should be defined objectively as the state which could be approached from the existing atmosphere by adiabatic adjustment, and be related to initial atmospheric state before adjustment. For the initial atmosphere state at any time, its corresponding ARS is different from the one at another time. Based on the above-mentioned conclusions, the reference state proposed by Lorenz cannot be obtained physically, so a new conception, the conditional minimum total potential energy, is put forward in order to objectively investigate atmospheric APE.

关键词： available potential energy adiabatic isentropic surface atmospheric reference state conditional minimum total potential energy.