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Advances in Atmospheric Sciences 2008年第4期25卷 555-562页

作者：辛晓歌 Zhaoxin LI 宇如聪周天军 State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 Graduate University of Chinese Academy of Sciences Beijing 100049 laboratoire de Mdteorologie dynamique IPSL/CNRS Universite Pierre et Marie Curie Paris France National Climate Center China Meteorological Administration Beijing 100081 State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences China Meteorological Administration Beijing 100081

Responses of late spring （21 April 20 May） rainfall to the upper tropospheric cooling over East Asia are investigated with a regional climate model based on laboratoire de M6t6orologie dynamique Zoom （LMDZ4-RCM）. A control experiment is performed with two runs driven by the mean ERA-40 data during 1958-1977 and 1981 2000, respectively. The model reproduces the major decadal-scale circulation changes in late spring over East Asia, including a cooling in the upper troposphere and an anomalous meridional cell. Accordingly, the precipitation decrease is also captured in the southeast of the upper-level cooling region. To quantify the role of the upper-level cooling in the drought mechanism, a sensitivity experiment is further conducted with the cooling imposed in the upper troposphere. It is demonstrated that the upper-level cooling can generate the anomalous meridional cell and consequently the drought to the southeast of the cooling center. Therefore, upper tropospheric cooling should have played a dominant role in the observed late spring drought over Southeast China in recent decades.

关键词： Southeast China spring drought inter-decadal variability regional climate modeling

Multi-Model Ensemble Projection of Precipitation Changes over China under Global Warming of 1.5 and 2℃ with Consideration of Model Performance and Independence

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Journal of Meteorological Research 2021年第1期35卷 184-197页

作者： Tong LI Zhihong JIANG Lilong ZHAO Laurent LI Joint International Research Laboratory of Climate and Environmental Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD) Nanjing University of Information Science&TechnologyNanjing 210044China Key Laboratory of Meteorological Disaster Ministry of Education(KLME)/CIC-FEMDNanjing University of Information Science&TechnologyNanjing 210044China laboratoire de Météorologie dynamique L’Institut Pierre-Simon Laplace(IPSL)Centre National de la Recherche Scientifique(CNRS)Sorbonne UniversitéEcole Normale SupérieureEcole PolytechniqueParis 75005France

A weighting scheme jointly considering model performance and independence(PI-based weighting scheme) is employed to deal with multi-model ensemble prediction of precipitation over China from 17 global climate models. Four precipitation metrics on mean and extremes are used to evaluate the model performance and independence. The PIbased scheme is also compared with a rank-based weighting scheme and the simple arithmetic mean(AM) scheme. It is shown that the PI-based scheme achieves notable improvements in western China, with biases decreasing for all parameters. However, improvements are small and almost insignificant in eastern China. After calibration and validation, the scheme is used for future precipitation projection under the 1.5 and 2℃ global warming targets(above preindustrial level). There is a general tendency to wetness for most regions in China, especially in terms of extreme precipitation. The PI scheme shows larger inhomogeneity in spatial distribution. For the total precipitation PRCPTOT(95 th percentile extreme precipitation R95 P), the land fraction for a change larger than 10%(20%) is 22.8%(53.4%)in PI, while 13.3%(36.8%) in AM, under 2℃ global warming. Most noticeable increase exists in central and east parts of western China.

关键词： model performance and independence multi-model ensemble mean and extreme precipitation future projection 1.5 and 2℃global warming

Mineralogy and Geochemistry of EtekéEburnean Gold deposit (Gabon)

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Open Journal of Geology 2022年第3期12卷 294-311页

作者： Makarim Dalil Nazaire Nzaou Mabika Amina Wafik Zohir Baroudi Abdelmalek Ouadjou Mohamed Gharrabi Amine Bouwafoud Nouamane El Aouad Youssef Zerhouni Saida Alikouss laboratoire géosciences et applications Faculté des sciences Ben M’sik Casablanca Morocco laboratoire dynamique de la Lithosphère et Genèse des Ressources Faculté des Sciences Semlalia Marrakech Morocco Managem Group Twin Center Casablanca Morocco

The Gabon geology offered favorable and natural environments for the formation of various types of mineralization. The Etéké gold district, aim of this study, is located in the Ngounié province (southern Gabon) on the western edge of the Chaillu massif. Geologically, the gold mineralization is associated with the Eburnean orogeny and hosted in the Archean greenstone belts. Also, this deposit is covered by a significant vegetation cover and a very extensive lateritic weathering profile, which hinders the most accurate study. Through this paper, we aim to propose a genesis pattern of this mineralization via a multidisciplinary approach. To do this, a petrographic, metallogenic, and geochemical characterization has been established in the different sectors of the Etéké deposit. The studied deposits display varied facies which are encased in granitoid. They are essentially formed of abundant granitoid, and amphibolite compared to the volcano-sedimentary formations. These rocks display magmatic textures, affected by metamorphism, and not sufficiently preserved. Based on our multidisciplinary approach, the studied samples collected from the core’s boreholes allowed us to decipher a volcanogenic and metamorphosed origin of the gold genesis.

关键词： Eburnean Orogeny Gabon Gold Greenstone Granitoids Amphibolite

Active Control of Chaotic Oscillations in Nonlinear Chemical Dynamics

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Journal of Applied Mathematics and Physics 2019年第3期7卷 547-558页

作者： Dagbégnon Luc Olabodé Batablinlè Lamboni Jean Bio Chabi Orou laboratoire de Mécanique des Fluides de la Dynamique Nonlinéaire et de la Modélisation des Systèmes Biologiques (LMFDNMSB) Institut de Mathématiques et de Sciences Physiques (IMSP) Porto-Novo Bénin Institut de Mathématiques et de Sciences Physiques (IMSP) Porto-Novo Bénin

Abstract: This work studies the active control of chemical oscillations governed by a forced modified Van der Pol-Duffing oscillator. We considered the dynamics of nonlinear chemical systems subjected to an external sinusoidal excitation. The approximative solution to the first order of the modified Van der Pol-Duffing oscillator is found using the Lindstedt’s perturbation method. The harmonic balance method is used to find the amplitudes of the oscillatory states of the system under control. The effects of the constraint parameter and the control parameter of the model on the amplitude of oscillations are presented. The effects of the active control on the behaviors of the model are analyzed and it appears that with the appropriate selection of the coupling parameter, the chaotic behavior of the model has given way to periodic movements. Numerical simulations are used to validate and complete the analytical results obtained.

关键词： Forced Modified Van der Pol-Duffing Oscillator Chemical Dynamics Active Control and Bifurcations

detection and Attribution of Changes in Summer Compound Hot and Dry Events over Northeastern China with CMIP6 Models

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Journal of Meteorological Research 2022年第1期36卷 37-48页

作者： Wei LI Zhihong JIANG Laurent ZXLI Jing-Jia LUO Panmao ZHAI Key Laboratory of Meteorological Disaster of Ministry of Education/Joint International Research Laboratory of Climate and Environment Change/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science&TechnologyNanjing 210044China Laboratory of Severe Weather Fujian Institute of Meteorological SciencesFuzhou 350001China laboratoire de Météorologie dynamique Centre National de la Recherche ScientifiqueSorbonne UniversitéEcole Normale SupérieureEcole PolytechniqueParis 75252France State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesChina Meteorological AdministrationBeijing 100081China

Northeastern China has experienced a significant increase in summer compound hot and dry events(CHdes),posing a threat to local agricultural production and sustainable *** study investigates the detectable anthropogenic signal in the long-term trend of CHde and quantifies the contribution of different external forcings.A probability-based index(PI)is constructed through the joint probability distribution to measure the severity of CHde,with lower values representing more severe *** of CHde to external forcing was assessed with simulations from the Coupled Model Intercomparison Project phase 6(CMIP6).The results show a significant increase in the severity of CHde over northeastern China during the past *** trend of regional averaged PI is-0.28(90%confidence interval:-0.43 to-0.13)per 54 yr and it is well reproduced in the historical forcing *** attribution method of optimal fingerprinting was firstly applied to a two-signal configuration with anthropogenic forcing and natural forcing;the anthropogenic impact was robustly detected and it explains most of the observed trend of ***,three-signal analysis further demonstrated that the anthropogenic greenhouse gases dominantly contribute to the observed change,while the anthropogenic aerosol and natural forcing have almost no contribution to the observed *** a compound event concurrently exceeding the 95 th percentile of surface air temperature and precipitation reversal in the current period,its likelihood exhibits little change at 1.5℃global warming,but almost doubled at 2.0℃global warming.

关键词： compound hot and dry event(CHde) detection and attribution northeastern China future projection

Statistical Study of foF2 Diurnal Variation at Dakar Station from 1971 to 1996:Effect of Geomagnetic Classes of Activity on Seasonal Variation at Solar Minimum and Maximum

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International Journal of Geosciences 2015年第3期6卷 201-208页

作者： Ali Mahamat Nour Ouattara Frederic Zerbo Jean Louis Gyebre Aristide Marie Frederic Nanema Emmanuel Zougmore Francois laboratoire de Materiaux et Environnement(LAME) UFR SEA Universite de OuagadougouOuagadougouBurkina Faso laboratoire de Recherche en Energetique et meteorologie de l’Espace(LAREME) Universite de KoudougouKoudougouBurkina Faso Institut des Sciences Exactes et Appliquees(ISEA) Universite Polytechnique de Bobo DioulassoBobo DioulassoBurkina Faso Centre National de Recherches Scientifiques et Techniques(CNRST) Institut de Recherches Scientifiques Appliquees et Technologies(IRSAT)OuagadougouBurkina Faso

The statistical study of F2 layer critical frequency at Dakar station from 1971 to 1996 is carried out. This paper shows foF2 statistical diurnal for all geomagnetic activities and all seasons and that during solar maximum and minimum phases. It emerges that foF2 diurnal variation graphs at Dakar station exhibits the different types of foF2 profiles in African EIA regions. The type of profile depends on solar activity, season and solar phase. During solar minimum and under quiet time condition, data show?the signature of a strength electrojet that is coupled with intense counter electrojet in the afternoon. Under disturbed conditions,?mean intense electrojet is observed in winter?during fluctuating and recurrent activities. Intense counter electrojet is seen under fluctuating and shock activities in all seasons coupled with strength electrojet in autumn. In summer?and spring under all geomagnetic activity condition, there is intense counter electrojet. During solar maximum, in summer and spring there is no electrojet under geomagnetic activity conditions.?Winter shows a mean intense electrojet. Winter and autumn are marked by the signature of the reversal electric field.

关键词： foF2 Diurnal Variation Solar Cycle Phases Geomagnetic Activity Classes Seasonal Effects E Region Electric Currents

A Spectroscopic Approach to Assess Heavy Metals Contents of the Mine Waste of Jalta and Bougrine in the North of Tunisia

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Journal of Geographic Information System 2012年第3期4卷 242-253页

作者： Sonia Gannouni Noamen Rebai Saadi Abdeljaoued Département de Géologie Université Tunis El Manar Faculté des Sciences de Tunis Dynamique des Bassins Sédimentaires Paléoenvironnements et Structures Géologiques laboratoire des Ressources Minérales et Environnement Faculté des Sciences de Tunis El Manar

Near InfraRed Spectroscopy (NIRS) has become an extremely important analytical technique in recent years and been applied in various geoscience areas such as mineral exploration and environmental studies. It is used for studying the physico-chemical properties of earth materials by enabling the interpretation of mineral composition and the study of its variability based on the diagnostic of spectral features. In this research, the application of laboratory reflectance spectroscopy in assessing heavy metals pollution is investigated. The potential use of reflectance spectroscopy in detecting Fe-related and clay minerals as well as the quantitative characterization of pollutants is studied for the mine waste of Jalta and Bougrine in the North of Tunisia. Mining activities of lead/Zn, have led to extensive pollution. The analysis of geochemical results outlined the level and spatial pattern of pollutants concentration. Results of the study showed that a relationship exists between reflectance spectra and geochemical measures of pollutants. The Spectral interpretation of Fe-related minerals and clay minerals showed that they are related to the pollutants and can be used as indirect spectral indicators of the pollution. The Fe-minerals include: jarosite, goethite, hematite/goethite, and hematite;clay minerals and feature-less (aspectral) materials. A direct quantitative relationship between pollutants and spectral parameters shows that Pb-Zn-Mn are the best correlated with a ratio of 610/500 nm range while Ni-Cr have a best correlation with a slope around 980 nm. Outputs from Partial Least Square Regression (PLSR) confirmed these relationships and also indicated that spectral parameters and reflectance values within 400 - 2500 nm range can better predict the contamination for Mn, Pb and Zn than for Ni and Cr but not for Fe, Cu, Cd, EC and pH.

关键词： Acid Mine Drainage Metals Leaching Geochemical Properties Spectral Properties Spectral Parameters PLSR (Partial Least Square Regression)

Upper-Ocean Lateral Heat Transports in the Nino3.4 Region and Their Connection with ENSO

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Journal of Meteorological Research 2022年第2期36卷 360-373页

作者： He ZHAO Tongwen WU Laurent ZXLI Fanghua WU Weihua JIE Xiangwen LIU Ronghua ZHANG Chengjun XIE Chinese Academy of Meteorological Sciences China Meteorological AdministrationBeijing 100081China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China Beijing Climate Center China Meteorological AdministrationBeijing 100081China laboratoire de Météorologie dynamique Centre National de la Recherche ScientifiqueSorbonne UniversitéEcole Normale SupérieureEcole PolytechniqueParis 75252France Key Laboratory of Ocean Circulation and Waves Institute of Oceanologyand Center for Ocean Mega-ScienceChinese Academy of SciencesQingdao 266071China Center for Excellence in Quaternary Science and Global Change Chinese Academy of SciencesXi’an 710061China

In the Nino3.4 region(tropical Pacific,5°S-5°N,170°-120°W),sea surface temperature(SST)changes are highly correlated with temperature variations in the upper 40-m *** study explores the upper-ocean heat budget in the Nino3.4 region using Ocean Reanalysis System 5(ORAS5)monthly data from 1979 to 2018,with a focus on ocean heat transports at lateral boundaries in the top 40-m layer and their correlation with temperature *** the region,there is a well-defined structure of opposite meridional circulation in the upper and lower parts of the thermocline,characterized by divergence in the upper layer above 40 m and convergence in the lower *** change of mean temperature in the upper layer is determined by the sum of zonal,meridional,and vertical heat transports,which,however,tend to largely compensate for each *** general,part of the surface heat flux from the atmosphere to the ocean and the heat transport from the subsurface ocean are transported out of the domain by meridional and zonal currents,leaving only a tiny part to warm or cool the upper *** amplitude of the net surface heat flux effective for the entire 40-m layer of the ocean is weaker than the lateral heat *** an interannual timescale,variations of heat transports in both zonal and meridional are positively correlated with temperature anomalies,while the vertical heat transport from the subsurface ocean is negatively *** analyses for five El Nino events and five La Nina events also revealed that there is a positive contribution of horizontal transport convergence to temperature anomalies during the evolution of El Nino(warming)and La Nina(cooling),while vertical transport acts against temperature variations.

关键词： heat budget lateral heat transport surface heat flux Ni?o3.4 region El Nino–Southern Oscillation(ENSO)

Modelling Uncertainty of Stream Networks derived from Elevation Data Using Two Free Softwares: R and SAGA

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Journal of Geographic Information System 2012年第2期4卷 153-160页

作者： Hammadi Achour Noamen Rebai Jean Van den Driessche Samir Bouaziz Compus de Beaulieu Université de Rennes Rennes France laboratoire 3E Ecole Nationale des Ingénieurs de Sfax Sfax Tunisia Unité de Recherche dynamique des Bassins Sédimentaires Paléoenvironnements et Structures Géologiques Département de Géologie Faculté des Sciences de Tunis Université Tunis El Manar Tunis Tunisie

Stream networks are considered important units in many environmental decision making processes. The extraction of streams using digital elevation models (deMs) presents many advantages. However it is very sensitive to the uncertainty of the elevation datasets used. The main aim of this paper is to implement geostatistical simulations and assess the propagated uncertainty and map the error of location streams. First, point sampled elevations are used to fit a variogram model. Next two hundred deM realizations are generated using conditional sequential Gaussian simulation;the stream network map is extracted for each of these realizations, and the collection of stream networks is analyzed to quantify the error propagation. At each grid cell, the probability of the occurrence of a stream and the propagated error are estimated. The more probable stream network are delineated and compared with the digital stream network derived from topographic map. The method is illustrated using a small dataset (8742 sampled elevations) for Anaguid Saharan platform. All computations are run in two free softwares: R and SAGA. R is used to fit variogram and to run sequential Gaussian simulation. SAGA is used to extract streams via RSAGA library.

关键词： deM Stream Network Uncertainty Modeling R SAGA

气候系统模式FGOALS_gl模拟的小冰期气候

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第四纪研究 2009年第6期29卷 1125-1134页

作者：张洁周天军满文敏李肇新中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室北京100029 中国科学院研究生院北京100049 laboratoire de meteorologie dynamique/CNRS Universite Paris 6 France

利用1650～1750年逐年变化的太阳辐照度等外强迫资料,驱动中国科学院大气物理研究所LASG发展的快速气候系统模式FGOALS_gl,模拟了小冰期(LIA)气候。把模拟的LIA表面温度变化与重建资料进行对比,结果表明FGOALS_gl对LIA气候具有较强的模... 详细信息

利用1650～1750年逐年变化的太阳辐照度等外强迫资料,驱动中国科学院大气物理研究所LASG发展的快速气候系统模式FGOALS_gl,模拟了小冰期(LIA)气候。把模拟的LIA表面温度变化与重建资料进行对比,结果表明FGOALS_gl对LIA气候具有较强的模拟能力,说明太阳辐照度的自然变化是导致小冰期气候的重要成因。模拟结果显示,LIA时期纬向平均温度变化表现为整个对流层降温,低纬度地区的降温中心位于对流层中层,北半球降温幅度大于南半球,高纬地区的降温幅度大于低纬地区。分析发现,中高纬地区的局地温度变化主要与环流异常相对应的冷暖平流有关;低纬地区的降温主要与赤道东风加强有关,东风增强通过增大蒸发和引起次表层冷海水上翻而令表层温度降低。LIA时期的降水变化主要位于中低纬地区,表现为日界线东(西)侧降水的负(正)异常。与降水异常相对应,Walker环流加强,东太平洋对流活动减弱,它与低纬地区对流层中层冷异常相联系。与大气层顶净短波辐射异常的季节变化相对应,南、北半球夏季平均表面温度异常较之冬季低0.28℃左右。

关键词：小冰期气候耦合模式模拟温度