Geochronology of the volcanic rocks in the Lu-Zong basin and its significance

The Lu-Zong (Lujiang-Zongyang) basin is one of the most important volcanic basins in the middle and lower reaches of the Yangtze River area, China. It comprises four shoshonitic volcanic units, which are, in an ascending order, the Longmenyuan, Zhuanqiao, Shuangmiao and Fushan Groups. The LA-ICP MS U-Pb zircon ages of the four units are: 134.8±1.8 Ma for the Longmenyuan Group, 134.1±1.6 Ma for the Zhuanqiao Group, 130.5±0.8 Ma for the Shuangmiao Group, and 127.1±1.2 Ma for the Fushan Group. The results indicate that all volcanic rocks in the Lu-Zong basin were formed in the Early Cretaceous from about 135 Ma to 127 Ma, lasting 8-10 Ma. There were no Jurassic volcanic activities in all the volcanic basins including the Lu-Zong basin in the middle and lower reaches of the Yangtze River area. This work has provided new chronological results for the further study and understanding of the tec- tonic, magmatic and metallogenic processes of eastern China in the Mesozoic.     

A scheme for regional rice yield estimation using ENVISAT ASAR data

Information on rice growing areas and rice production is critical for most rice growing countries to make state and economic policies. However, the areas where rice crop is cultivated are often cloudy and rainy, which entails the use of radar remote sensing data for rice monitoring. In this paper, a practical scheme to integrate multi-temporal and multi-polarization ENVISAT ASAR data into rice crop model for regional rice yield estimation has been presented. To achieve this, rice distribution information should be obtained first by rice mapping method to retrieve rice fields from ASAR images, and then an assimilation method is applied to use the observed multi-temporal rice backscattering coefficients which are grouped for each rice pixel to re-initialize ORYZA2000 to predict rice yield. The assimilation method re-initializes the model with optimal input parameters, allowing a better temporal agreement between the rice backscattering coefficients retrieved from ASAR data and the rice backscattering coefficients simulated by a coupled model, i.e., the combination of ORYZA2000 and a semi-empirical rice backscatter model through LAI. The SCE-UA optimization algorithm is employed to determine the optimal set of input parameters. After the re-initialization, rice yield for each rice pixel is calculated, and the yield map over the area of interest is produced. The scheme was validated over Xinghua study area located in the middle of Jiangsu Province of China by using the data set of an experimental campaign carried out during the 2006 rice season. The result shows that the obtained rice yield map generally overestimates the actual rice production by 13% on average and with a root mean square error of approximately 1133 kg/ha on validation sites, but the tendency of rice growth status and spatial variation of the rice yield are well predicted and highly consistent with the actual production variation. Supported by the ESA-NRSCC Dragon Cooperation Program (), the Project for Jiangsu Graduate in Scientific Research and Innovation (No. CX07B_048z), and the Special Program for Scientific Research in Public Welfare Meteorological Services (No. GYHY200806008)     

New discovery of Palaeontinid fossils from the Middle Jurassic in Daohugou, Inner Mongolia (Homoptera, Palaeontinidae)

Three new species of fossil Palaeontinidae are described from Daohugou Village, Inner Mongolia, China: Daohugoucossus shii sp. nov., D. parallelivenius sp. nov., D. lii sp. nov. The diagnosis of Dao- hugoucossus Wang, Zhang and Fang, 2006 is revised. These materials are the first complete fossil palaeontinids in the Middle Jurassic of the world. Based on observation of these new specimens, Sc of this new genus has the following combined characters: joined with R at base, diverged near M separa- tion, coalesced with R before the nodal line, extended beyond the nodal line and fused with R1 before distal end. Due to the Sc characteristics mentioned above, the genus Liaocossus Ren, Yin and Dou, 1998 can be well distinguished from “Ilerdocossus-complex”.     

城市化对北京气象站极端气温指数趋势变化的影响

利用5个乡村气象站和北京气象站(简称北京站)1960~2008年日最高、最低气温资料,比较分析了北京地区城市和乡村极端气温指数年、季节的时间变化以及城市化对北京站各极端气温指数趋势变化的影响.结果表明:1960~2008年北京站霜冻日数、冷夜日数、冷昼日数和平均日较差均显著减少,暖夜日数、暖昼日数、平均最高气温和平均最低气温均显著上升,这些指数的趋势变化全部通过了0.01显著性水平检验,其中霜冻日数、冷夜日数、暖夜日数、平均最低气温、平均气温日较差等与最低气温有关的极端气温指数比冷昼日数、暖昼日数、平均最高气温等基于最高气温记录的极端气温指数变化趋势更明显;城市化因素已致使北京站1960~2008年期间霜冻日数、冷夜日数和平均气温日较差显著减少,暖夜日数和平均最低气温显著增加,这些与最低气温有关的极端气温指数序列,其城市化影响都通过了0.01显著性水平检验.在北京站的霜冻日数、冷夜日数和平均气温日较差长期减少趋势中,城市化影响分别达到-5.78 d/10a、-17.83 d/10a和-0.73 ℃/10a,而在北京站暖夜日数和平均最低气温增加趋势中,城市化影响分别为14.76 d/10a和0.70 ℃/10a.在所有与最低气温有关的年平均极端气温指数的趋势变化中,城市化影响贡献率均达到100%,即观测到的趋势变化完全是由城市化因素造成的.城市化致使四季北京站冷夜日数、平均气温日较差均显著减少,暖夜日数、平均最低气温均显著增加,其中平均最低气温和平均气温日较差序列中的城市化影响在冬季最大,暖夜日数序列中的城市化影响在夏季最显著.     

Urban effects and summer thunderstorms in a tropical cyclone affected situation over Guangzhou city

With data mainly from Guangzhou mesonet Automatic Weather Stations (AWS), Guangzhou Doppler Radar and satellite T _BB data, characteristics and evolution of the urban heat island (UHI) over Guangzhou City were analyzed in a tropical cyclone affected situation for early August 2005. In particular, two thunderstorms occurring during this period respectively at the night of 4 August and in the afternoon of 7 August were investigated to study the relationships between the development of thunderstorms and the UHI. Results showed that two thunderstorms were associated with the UHI effects. UHI induced local air convergence and initiated the thunderstorm convections. Both cases showed a general agreement in time and space for the locations of maximum UHI, convergence, convection, and precipitation. Convection was found to be more favorable to developing in time periods and locations with stronger intensity of UHI. Analysis also showed that, due to the urban effects, both thunderstorms got strengthened when moving over Guangzhou City, with maximum radar echoes observed right over the urban area and precipitation located within the city. All these features reveal that two thunderstorms were urban-induced storms. Supported jointly by the R&D Infrastructure and Facility Developemnt Program (2003DIB4J145) from the Ministry of Science and Technology of China, Urban Meteorological Science Research Fund (UMRF200504) and the Open Research Fund from the State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences     

Effect of urbanization on the winter precipitation distribution in Beijing area

According to the urbanization extent of Beijing area, and with 1980 as a turning point, the duration from 1961 to 2000 is divided into two periods: one is defined as the slow urbanization period from 1961 to 1980, and other one as the fast urbanization period from 1981 to 2000. Based on the 40-year’s precipi-tation data of 14 standard weather stations in Beijing area, the effect of urbanization on precipitation distribution is studied. It is found that there has been a noticeable and systematic change of wi...     

Bifurcation of Pacific North Equatorial Current at the surface

The grid altimetry data between 1993 and 2006 near the Philippines were analyzed by the method of Empirical Orthogonal Function (EOF) to study the variation of bifurcation of the North Equatorial Current at the surface of the Pacific. The relatively short-term signals with periods of about 6 months, 4 months, 3 months and 2 months are found besides seasonal and interannual variations mentioned in previous studies. Local wind stress curl plays an important role in controlling variation of bifurcation latitude except in the interannual timescale. The bifurcation latitude is about 13.3°N in annual mean state and it lies at the northernmost position (14.0°N) in January, at the southernmost position (12.5°N) in July. The amplitude of variation of bifurcation latitude in a year is 1.5°, which can mainly be explained as the contributions of the signals with periods of about 1 year (1.2°) and 0.5 year (0.3°). Supported by National Basic Research Program of China (Grant No. 2007CB411802), National Natural Science Foundation of China (Grant Nos. 40806012, 40876013), Open Fund of the Key Laboratory of Ocean Circulation and Waves, Chinese Academy of Sciences (Grant No. KLOCAW0803) and Scientific Research Foundation for Talent, Guangdong Ocean University (Grant No. E06118)     

Conditional nonlinear optimal perturbation: Applications to stability,sensitivity, and predictability

Conditional nonlinear optimal perturbation (CNOP) is a nonlinear generalization of linear singular vector (LSV) and features the largest nonlinear evolution at prediction time for the initial perturbations in a given constraint. It was proposed initially for predicting the limitation of predictability of weather or climate. Then CNOP has been applied to the studies of the problems related to predictability for weather and climate. In this paper, we focus on reviewing the recent advances of CNOP’s applications, which involves the ones of CNOP in problems of ENSO amplitude asymmetry, block onset, and the sensitivity analysis of ecosystem and ocean’s circulations, etc. Especially, CNOP has been primarily used to construct the initial perturbation fields of ensemble forecasting, and to determine the sensitive area of target observation for precipitations. These works extend CNOP’s applications to investigating the nonlinear dynamical behaviors of atmospheric or oceanic systems, even a coupled system, and studying the problem of the transition between the equilibrium states. These contributions not only attack the particular physical problems, but also show the superiority of CNOP to LSV in revealing the effect of nonlinear physical processes. Consequently, CNOP represents the optimal precursors for a weather or climate event; in predictability studies, CNOP stands for the initial error that has the largest negative effect on prediction; and in sensitivity analysis, CNOP is the most unstable (sensitive) mode. In multi-equilibrium state regime, CNOP is the initial perturbation that induces the transition between equilibriums most probably. Furthermore, CNOP has been used to construct ensemble perturbation fields in ensemble forecast studies and to identify sensitive area of target observation. CNOP theory has become more and more substantial. It is expected that CNOP also serves to improve the predictability of the realistic predictions for weather and climate events plays an increasingly important role in exploring the nonlinear dynamics of atmospheric, oceanic and coupled atmosphere-ocean system. Supported by National Basic Research Program of China (Grant Nos. 2006CB403606, 2007CB411800), National Natural Science Foundation of China (Grant Nos. 40830955, 40675030, 40505013), Institute of Atmospheric Physics, Chinese Academy of Sciences (Grant No. IAP07202), and LASG State Key Laboratory Special Fund     

Microbial and molecular fossils from the Permian Zoophycos in South China

The trace fossil Zoophycos was enriched in the lower part of the Guadalupian Maokou Formation of Permian in Laibin, Guangxi of South China, and characterized by observable lamellae within its spreiten. Associated with these lamellae are the prolific coccus- and spirillum-shaped microbe fossils. These microbes morphologically identified are 0.4―3.0 μm in diameter or length. Molecular fossils, including normal alkanes (dominated by C18, without an odd-over-even predominance), acyclic isoprenoids (such as pristane (Pr) and phytane (Ph)), extended tricyclic terpanes, pentacyclic triterpanes, steranes, al-kylcyclohexanes, dibenzothiophenes, benzonaphthothiophenes, benzobisbenzothiophenes, were in-strumentally identified in the wackestone characterized by the occurrence of abundant Zoophycos (composite ichnofabric indices are 4) and crowded microbial fossils. The value of the Pr/Ph ratio is less than 1, indicative of a dysoxic condition. The identification of abundant sulfur compounds (the thio-phene series) related to the contribution of reductive sulfur favors the occurrence of sulphate-reducing bacteria. The association of abundant microbial colonies with microbial molecular fossils within the spreiten suggests that trace fossils Zoophycos would be a multifunctional garden carefully constructed by the Zoophycos-producer, where different microbial colonies were orderly and carefully planted and cultured in different minor lamellae within spreiten. Hence, it is proposed that the Zoophycos-producer symbiosed with microbial colonies on the mutual basis of food supply and the redox conditions.     

Coupling relationships between brachiopods and Girvanella during the Late Devonian F-F transition in Guilin, South China

The abundance curves derived from area proportions of brachiopods and Girvanella in the thin sections from the Yangdi section, South China, exhibits complex relationships during the Late Devonian Frasnian-Famennian transition. The living activity of brachiopods such as grazing and borrowing did great damage to the growth of Girvanella. However, there was more to just a mere a survival competing relationship between them, Girvanella actually improved marine environments by oxygenating the dysoxic ambient sea-water through photosynthesis in the lower Kellwasser Horizon. Profited from this improvement brachiopods’ abundance increased subsequently and suppressed Girvanella again. Nonetheless, without Girvanella’s photosynthesis, brachiopods were wiped out by the farther anoxic environments in the upper Kellwasser Horizon. The complex relationships between Girvanella and brachiopods may be a key to unlocking the relationships between geomicrobes and metazoans in the geological overturn periods. Supported by NSFC Innovation Research Group Program (Grant No. 40621002), MOE Innovative Research Team Program (Grant No. IRT0546), the National Natural Science Foundation of China (Grant Nos. 40472020, 40730209, 40802005 and 40872001) and SINOPEC Project (Grant No. G0800-06-ZS-319)     

The trend,seasonal cycle,and sources of tropospheric NO<Subscript>2</Subscript> over China during 1997–2006 based on satellite measurement

The characteristics of spatial and temporal distribution of tropospheric NO2 column density concentration over China are presented, on the basis of measurements from the satellite instruments GOME and SCIAMACHY. From these observations, monthly averaged tropospheric NO2 variations are determined for the period of 1997 to 2006. The trend and seasonal cycle are also investigated. The possible source of tropospheric NO2 over megacity area is discussed in this paper. The results show a large growth of tropospheric NO2 over eastern China, especially above the industrial areas with a fast economical growth, such as, Yangtze Rive Delta region and Pearl River Delta region because of the prominent anthropogenic activity. There is a rapid increase of tropospheric NO2 over megacities in China. For instance, Shanghai had a linear significant increase in NO2 columns of ～20% per year (reference year 1997) in the period of 1997-2006, which is the rapidest increase among all the selected cities. The seasonal pattern of the NO2 concentration shows a difference between the east and west in China. In the eastern part of China, an expected winter maximum in seasonal cycle is found because of the prominent anthropogenic activity and meteorological conditions. In the western part this cycle shows a NO2 maximum in summer time, which is attributed to natural emissions, especially soil emissions and lightning. A quickly increasing vehicle population may contribute to the increase of tropospheric NO2 over megacities in China for the remarkable correlation for vehicle population with tropospheric NO2.     

Characteristics of landscape information Tupu of the Yellow River swings and its subdeltas during 1855―2000

Based on the theories and methods of cartography on spatial pattern and temporal evolution in Geo-information Tupu (Carto-methodology in Geo-information, CMGI) and the quantitative measurements of pattern and process in landscape ecology, the methodology of landscape information Tupu in studying the swing process of the Yellow River (YR) over the Yellow River Delta (YRD) during 1855―2000 has been demonstrated. The main content includes (1) methodology of landscape information Tupu; (2) evolution process Tupu of YR rump channels; (3) evolution process Tupu of the 7 pieces of subdeltas in YRD during 1855―2000; (4) landscape information Tupu of the modern YRD and the current YRD; (5) landscape information Tupu of YR rump channels on the 7 pieces of subdeltas during 1855―2000; and (6) corridor-matrix landscape information Tupu by YR swings. The methodology of landscape information Tupu here is still primary but we hope that it could provide a new tool for exploring an integrated research on spatiotemporal approaches for landscape "pattern and process".     

SNR changes of VLF radio signals detected onboard the DEMETER satellite and their possible relationship to the Wenchuan earthquake

Here we used the VLF signal data received by the DEMETER satellite, transmitted from various ground VLF transmitters which are located around China, to study the changes in the signal to noise ratio (SNR) before and after the Wenchuan earthquake, which had a magnitude of 8.0. We also found that the SNRs of different frequency signals decreased significantly over the epicenter region before the earthquake, and reverted to their original levels after the earthquake. This phenomenon may be related to the earthquake. Special Foundation of Basic Research from Institute of Geophysics, China Earthquake Administration (Grant No. DQJB08Z08), National Key Technology R & D Program (Grant No. 2008BAC35B01)     

Starch grain analysis reveals function of grinding stone tools at Shangzhai site,Beijing

Prehistoric groundstone tools including slabs (metate, mo-pan) and mullers (mano, mo-bang) are often considered to be tools that were used to process cereals in ancient China. Most archaeologists believe that groundstone tools are indicators of an agrarian economy. This study employed starch grain analysis to examine a slab and a muller excavated from the Shangzhai Site (7500–7000 cal a BP), Beijing. Identifiable starch grains recovered from the stone tools were classified into 9 genera and 12 species, most of which were from acorns and foxtail millets. Remains from the oak species Q. mongolicus, Q. acuttssima, and Q. dentate were identified as well as a few starch grains from broomcorn (Panicum miliaseum) and bean (Vigna sp.). Other starch grains were from unidentifiable roots and grasses. A variety of starch grains indicates that the grinding stone tools were used to process not only cereals, but also other seeds or roots that had to be ground or husked, thus bringing into question the aforementioned cereal hypothesis. Because the numbers of starch grains from nuts and millets were so large, both gathering and cultivation might have been important economic patterns before 7000 years ago in Beijing area. Moreover, the starch remains are derived from plants that indicate that the paleoclimate of Beijing was wetter and warmer than today’s. Supported by National Natural Science Foundation of China (Grant No. 40771205), National Science Fund for Distinguished Young Scholars (Grant No. 40625002) and Knowledge Innovation Project from Chinese Academy of Sciences (Grant No. KZC2-YW-315-5)     

Distributed modeling of monthly air temperatures over the rugged terrain of the Yellow River Basin

Our analyses of the monthly mean air temperature of meteorological stations show that altitude, global solar radiation and surface effective radiation have a significant impact on air temperature. We set up a physically-based empirical model for monthly air temperature simulation. Combined the proposed model with the distributed modeling results of global solar radiation and routine meteorological observation data, we also developed a method for the distributed simulation of monthly air temperatures over rugged terrain. Spatial distribution maps are generated at a resolution of 1 km×1 km for the monthly mean, the monthly mean maximum and the monthly mean minimum air temperatures for the Yellow River Basin. Analysis shows that the simulation results reflect to a considerable extent the macro and local distribution characteristics of air temperature. Cross-validation shows that the proposed model displays good stability with mean absolute bias errors of 0.19°C–0.35°C. Tests carried out on local meteorological station data and case year data show that the model has good spatial and temporal simulation capacity. The proposed model solely uses routine meteorological data and can be applied easily to other regions. Supported by China Meteorological Administration key Project on New Technique Diffusion (Grant No. CMATG2006Z10) and Jiangsu Key Laboratory of Meteorological Disasters (Grant No. KLME050102)     

Petrogenetic significance of high Fe/Mn ratios of the Cenozoic basalts from eastern China

The Cenozoic basalts from eastern China show commonly high Fe/Mn ratios (average = 68.6 ± 11.5) coupled with OIB-type trace element signature. The Cenozoic basalts form the northern margin and the southern margin of the North China Craton are studied in detail. Model calculations point out that the coupling feature of high Fe/Mn ratio with OIB-type trace element signature of these basalts cannot be produced by neither pyroxene/olivine crystallization nor remelting of previously melted mantle, but require partial melting of a garnet pyroxenite-rich mantle source. Combining these features of the Cenozoic basalts with the Phanerozoic lithospheric evolution of the eastern China, we suggest that the Cenozoic basalts were derived from a garnet pyroxenite-rich mantle source associated with continental crust delamination or oceanic crust subduction.     

Development and deployment of an instrument for measurement of atmospheric peroxy radical by chemical amplification

An instrument for measurement of peroxy radical by chemical amplification (PERCA) has been devel- oped at Peking University (PKU) and deployed in several field campaigns. PKU PERCA measures per- oxy radical via amplification of NO2 by peroxy radical in the presence of NO and CO through a chain reaction. The amount of amplified NO2 is detected by a NO2-luminal chemiluminescence detector. The chain length (CL) of 75±20 (1σ ) was determined routinely during field campaigns using a HO2 source from photolysis of...     

A semi-implicit semi-Lagrangian global nonhydrostatic model and the polar discretization scheme

The Global/Regional Assimilation and PrEdiction System(GRAPES) is a newly developed global non-hydrostatic numerical prediction model,which will become the next generation medium-range opera-tional model at China Meteorological Administration(CMA).The dynamic framework of GRAPES is featuring with fully compressible equations,nonhydrostatic or hydrostatic optionally,two-level time semi-Lagrangian and semi-implicit time integration,Charney-Phillips vertical staggering,and complex three-dimensional pre-conditioned Helmholtz solver,etc.Concerning the singularity of horizontal momentum equations at the poles,the polar discretization schemes are described,which include adoption of Arakawa C horizontal grid with ν at poles,incorporation of polar filtering to maintain the computational stability,the correction to Helmholtz equation near the poles,as well as the treatment of semi-Lagrangian interpolation to improve the departure point accuracy,etc.The balanced flow tests validate the rationality of the treatment of semi-Lagrangian departure point calculation and the polar discretization during long time integration.Held and Suarez tests show that the conservation proper-ties of GRAPES model are quite good.     

谈地震科学基金课题档案管理

根据实际情况确定了地震科学基金课题档案归档范围，就如何做好地震科学基金课题档案管理，从行政监督制约、档案人员的管理作用等方面进行探索，并通过实践取得了较好效果。     

Seismic anisotropy of upper mantle in eastern China

Based on the polarization analysis of teleseismic SKS waveform data recorded at 65 seismic stations which respectively involved in the permanent and temporary broadband seismograph networks deployed in eastern China, the SKS fast-wave direction and the delay time between the fast and slow shear waves at each station were determined by use of SC method and the stacking analysis method, and then the image of upper mantle anisotropy in eastern China was acquired. In the study region, from south to north, the fast-wave polarization directions are basically EW in South China, gradually clockwise rotate to NWW-SEE in North China, then to NW-SE in Northeast China. The delay time falls into the interval [0.41 s, 1.52 s]. Anisotropic characteristics in eastern China indicate that the upper mantle anisotropy is possibly caused by both the collision between the Indian and Eurasian Plates and the subduction from the Pacific and Philippine Sea Plates to the Eurasian Plate. The collision between two plates made the crust of western China thickening and uplifting and the material eastwards extruding, and then caused the upper mantle flow eastwards and southeastwards. The subduction of Pacific Plate and Philippine Sea Plate has resulted in the lithosphere and the asthenosphere deformation in eastern China, and made the alignment of upper mantle peridotite lattice parallel to the deformation direction. The fast-wave polarization direction is consistent with the direction of lithosphere extension and the GPS velocity direction, implying that the crust-upper mantle deformation is possibly a vertically coherent deformation. Supported by Special Project for the Fundamental R & D of Institute of Geophysics, China Earthquake Administration (Grant No. DQJB06B06), Special Program of the Ministry of Science and Technology of China (Grant No. 2006FY110100), China Digital Earthquake Observation Network Project “North China Seismic Array”, and National Natural Science Foundation of China (Grant Nos. 40334041 and 40774037)