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Geodesy and Geodynamics 2024年第1期15卷 13-26页

作者： Xianjie Li Jean-pierre Barriot Bernard Ducarme Marania Hopuare Yidong Lou Geodesy Observatory of Tahiti University of French PolynesiaFaa'a 98702French Polynesia Catholic University of Louvain Georges Lemaître Centre for Earth and Climate Research(ELI)1348 Louvain-la-NeuveBelgium GNSS Research Center Wuhan UniversityWuhan 430079China State Key laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhan 430079China

In this study,we estimate the absolute vertical land motions at three tidal stations with collocated Global Navigation Satellite System(GNSS)receivers over French Polynesia during the period 2007-2020,and obtain,as ancillary results,estimates of the absolute changes in sea level at the same *** verify our processing approach to determining vertical motion,we first modeled vertical motion at the International GNSS Service(IGS)THTI station located in the capital island of Tahiti and compared our estimate with previous independent determinations,with a good *** obtained the following estimates for the vertical land motions at the tide gauges:Tubuai island,Austral Archipelago-0.92±0.17 mm/yr,Vairao village,Tahiti Iti:-0.49±0.39 mm/yr,Rikitea,Gambier Archipelago-0.43±0.17 mm/*** absolute variations of the sea level are:Tubuai island,Austral Archipelago 5.25±0.60 mm/yr,Vairao village,Tahiti Iti:3.62±0.52 mm/yr,Rikitea,Gambier Archipelago 1.52±0.23 mm/*** discuss these absolute values in light of the values obtained from altimetric measurements and other means in French Polynesia.

关键词： GPS Tide gauges Sea level changes Vertical land motion

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火山喷发对陆地植被与碳循环影响的研究进展

科学通报 2024年第2期69卷 160-168页

作者：张原梁尔源汪涛朴世龙中国科学院青藏高原研究所高寒生态重点实验室北京100101 laboratory for Sciences of climate and Environment Institute Pierre-Simon LaplaceFrench Alternative Energies and Atomic Energy Commission/French National Centre for Scientific Research/Versailles-St-Quentin UniversityGif sur Yvette 91191France 中国科学院青藏高原地球科学卓越创新中心北京100101 北京大学城市与环境学院北京100871

1991年,Pinatubo火山喷发导致全球大气二氧化碳浓度上升态势出现停滞,这一现象揭示了地球内部系统可以通过火山活动对地表生物地球化学循环产生重大影响.近些年,火山喷发对陆地生态系统的影响及其驱动机制引起科学界的广泛讨论.本文系... 详细信息

1991年,Pinatubo火山喷发导致全球大气二氧化碳浓度上升态势出现停滞,这一现象揭示了地球内部系统可以通过火山活动对地表生物地球化学循环产生重大影响.近些年,火山喷发对陆地生态系统的影响及其驱动机制引起科学界的广泛讨论.本文系统梳理了火山喷发对陆地生态系统影响的研究,总结了火山活动的辐射效应和气候效应对树木生长和陆地碳循环产生影响的机制.大型火山喷发形成的平流层气溶胶一方面引起散射辐射增加促进光合作用,另一方面,还引起总辐射减弱抑制光合作用,由于散射辐射的影响相比更强,总体上火山辐射效应有利于陆地碳汇的增加.火山的气候效应体现在全球尺度的降温和区域降水的改变.降温作用在低纬地区促进植被的光合作用,在高纬地区抑制光合作用,同时在全球尺度减弱生态系统的呼吸作用,总体上也有利于增加碳汇.对火山造成降水变化影响的评估目前还存在较大不确定性.在对这些机制总结的基础上,本文评述了当前的认识盲点和研究难点,以期为未来进一步推进火山喷发影响的研究、完善地球内外系统联动机制的认识提供参考.

关键词：火山爆发陆地生态系统火山冷却效应散射辐射碳循环

Modelling marine DOC degradation time scales

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National Science Review 2018年第4期5卷 468-474页

作者： Luca Polimene Richard B.Rivkin Ya-Wei Luo Eun Young Kwon Marion Gehlen M.Angelica Pe?a Nannan Wang Yantao Liang Hermanni Kaartokallio Nianzhi Jiao Plymouth Marine laboratory Department of Ocean Sciences Memorial University of Newfoundland State Key laboratory of Marine Environmental Science College of Ocean and Earth SciencesXiamen University Center for climate Physics Institute for Basic ScienceSouth Korea Laboratoire des Sciences du Climat et de l'Environnement Institut Pierre Simon LaplaceCEA-CNRS-UVSQ Institute of Ocean Sciences Fisheries and Oceans Canada Key laboratory of Biofuels Shandong Provincial Key Laboratory of Energy Genetics Qingdao Institute of Bioenergy and Bioprocess TechnologyChinese Academy of Sciences Finnish Environment Institute Marine Research Centre

INTRODUCTION Marine dissolved organic carbon(DOC)is formed of a large number of highly diverse *** on the environmental conditions,a fraction of these molecules may become progressively resistant to bacterial degradation and accumulate in the ocean for extended time *** longlived DOC(the so-called recalcitrant DOC,RDOC)is thought to play an

关键词： DOC Modelling marine DOC degradation time scales

The Sword of Damocles behind the Curtain of the Earth’s Global Warming: A Review

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International Journal of Geosciences 2024年第2期15卷 119-136页

作者： Jacques Bourgois Institut des Sciences de la Terre Paris (iSTeP) Unité Mixte de Recherche (UMR) 7193 Université Pierre et Marie Curie (UPMC)/Université Paris 06 Paris France iSTeP UMR 7193 Centre National de la Recherche Scientifique (CNRS) Paris France

The “mainstream” climatology (MSC)—i.e. which includes the Intergovernmental Panel on climate Change (IPCC) community—considers the present day massive release of greenhouse gases into the atmosphere as the main cause of the current global warming trend. The main inference from this stance is that the increase in temperature must occur after the release of greenhouse gases originating from the anthropic activities. However, no scientific evidence has been provided for this basic notion. Earth paleoclimatic records document the antecedence of temperature over CO2 levels. For the past 65 Ma, the temperature parameter has controlled the subsequent increase in CO2. This includes the three rapid aberrant shifts and extreme climate transients at 55 Ma, 34 Ma, and 23 Ma REF _Ref159913672 \r \h \* MERGEFORMAT [1]. The simple fact of their existence points to the potential for highly nonlinear responses in climate forcing. Whatever these shifts and transients are, CO2 remains a second order parameter in their evolution through time. Confronted with the past, a suitable response must therefore be given to the unresolved question of whether the CO2 trends precede the temperature trends in the current period, or not. The assertion that the current global warming is anthropogenic in origin implicitly presupposes a change of paradigm, with the consequence (the increase in CO2 levels) that occurred in Earth’s past being positioned as the cause of the warming for its present day climatic evolution. The compulsory assumption regarding the antecedence of CO2 levels over the temperature trends is associated with the haziness of the methodological framework—i.e. the paradigm—and tightens the research fields on the likely origins of global warming. The possible involvement of an “aberrant” natural event, hidden behind the massive release of greenhouse gases, has not been considered by the MSC.

关键词： climate CO2 Temperature Paleoclimate Warming

Impacts of Upper Tropospheric Cooling upon the Late Spring Drought in East Asia Simulated by a Regional climate Model

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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

Modelling the Current and Future Spatial Distribution Area of Shea Tree (<i>Vittelaria paradoxa</i>C. F. Gaertn) in the Context of climate Change in Benin

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American Journal of climate Change 2021年第3期10卷 263-281页

作者： Yasminath Judith Follone Avaligbé Faki Oyédékpo Chabi Césaire Paul Gnanglè Orou Daouda Bello Ibouraïma Yabi Léonard Ahoton Aliou Saïdou Integrated Soil and Crop Management Research Unit Laboratory of Soil Sciences Crop Sciences School Faculty of Agronomic Sciences University of Abomey-Calavi Abomey-Calavi Benin Agricultural Research Centre (CRA) of Agonkanmey National Agricultural Research Institute of Benin (INRAB) Cotonou Benin laboratory pierre pagney “climate Water Ecosystem and Development (LACEEDE)” Department of Geography and Land Management (DAGT) Faculty of Human and Social Sciences (FASHS) University of Abomey-Calavi Abomey-Calavi Benin

In Benin, Shea tree (Vitellaria paradoxa) is one of the agroforestry species of great socio-economic importance for local populations. Given the actual variation in the climate parameters, it is necessary to anticipate the future spatial distribution of Shea trees as an adaptation strategy and for designing relevant conservation strategies. The aim of the present research was to evaluate the influence of climate change on the distribution areas of Shea trees in Benin. Occurrence data consisting of geographic coordinates of Shea trees in Benin as well as bioclimatic variables were recorded. Furthemore, additional presence points were collected from the Global Biodiversity Information Facility database website. Current and future environmental data for the study area were obtained from the Africlim website. Bioclimatic variables (moisture and temperature), monthly maximum and minimum temperatures and annual rainfall were collected from Worldclim synoptic stations website for the period 1970-2000. The aridity index was created from the potential evapotranspiration (PET) and annual rainfall, using spatial analysis tools of ArcGIS. The impact of current and future environmental conditions on favourable Shea trees’ growing area was assessed following the maximum entropy (MaxEnt) approach under two climate scenarios (RCP 4.5 and RCP 8.5). Under the current climate conditions, 80% of Benin territory and 79% of the protected areas were highly favourable for Shea trees growing and conservation. However, all climate scenarios projected the significant decrease of 14% to 19% of the distribution of favourable for Shea tree growing area and 26% to 30% of the protected areas by 2055 in favour of non-favourable for the trees’ distribution. The protection of habitats favourable for the species development, coupled with a quick restoration of the species through the use of appropriate vegetative propagation techniques are required to sustain the species’ conservation in Benin and mai

关键词： Bioclimatic Variables Agroforestry Scenario Analysis Adaptation Strategy Conservation

Paleoenvironmental implications of the calcium isotope characteristics in the MD81349 from the Nintyeast Ridge in the Indian Ocean

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Acta Oceanologica Sinica 2018年第9期37卷 59-66页

作者： WANG Feng FANG Nianqiao HU Chaoyong GOLDSMITH Sarah XU Yonghang DING Xuan WANG Aijun CHEN Ping BAO Rui Third Institute of Oceanography State Oceanic Administration Xiamen 361005 China Institute of Marine Geology and Geophysics China University of Geosciences (Beijing) Beijing 100083 China School of Earth Sciences China University of Geosciences Wuhan 430074 China Demo laboratory Ctd. MicroMass Mantchestt M139PL United Kingdom School of Earth Science Environmental Engineering Anhui University of Science and Technology Huainan 232001 China climate and Environment Sciences laboratory of the institute pierre Simon Laplace (LSCE) Gif sur Yvette 75000 France

A δ^（44） Ca curve from shells of the planktonic foraminifera Globigerinoides sacculifer in calcareous biogenic oozes has been extracted from the Nintyeast Ridge in the Indian Ocean since 300 ka. By combining terrigenous inputs（e.g., grain size, magnetic susceptibility, and turbidite frequency） with the oceanic productivity（e.g., biogenic content and Neogloboquadrina dutertrei content）, it is found that the curve＇s variations are closely related to the historical evolution of the oceanic calcium cycle. The δ^（44）Ca value is in lower tendency and has small oscillation during Marine Isotope Stage（MIS） 6, when the supply of terrigenous detrital is highest. In contrast, during MIS 3,5 and 7, the δ^（44） Ca values are in higher tendency, and their fluctuations are consistent with the variations of the productivity proxies. These results suggest that the calcium isotopes are mainly influenced by the input of the Himalayan erosion products to the northern Indian Ocean. In addition, the developmental stages of calcareous planktons may have a secondary impact on the fluctuations of the calcium isotope ratio of sea water.

关键词： Nintyeast Ridge calcium isotope paleoceanography Indian Ocean

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

Thermal convection in ice sheets: New data, new tests

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Natural Science 2012年第7期4卷 409-418页

作者： Terence J. Hughes Emeritus of Earth Sciences and climate Change University of Maine 404 North Sixth Street Fort Pierre South Dakota 57532 USA

Thermal convection in the Antarctic Ice Sheet was proposed in 1970. Demonstrating its existence proved to be elusive. In 2009, tributaries to ice streams were postulated as the surface expression of underlying thermal convection rolls aligned in directions of advective ice flow. Two definitive tests of this hypothesis are now possible, using highly accurate ice elevations and velocities provided by the European, Japanese, and Canadian Space Agencies that allow icestream tributaries and their velocities to be mapped. These tests are 1) measuring lowering of tributary surfaces to see if lowering is due only to advective ice thinning, or also requires lowering en masse in the broad descending part of convective flow, and 2) measuring transverse surface ice velocities to see if ice entering tributaries from the sides increases while crossing lateral shear zones, as would be required if this flow is augmented by convective flow ascending in the narrow side shear zones and diverted into tributaries by advective ice flow. If (1) and (2) are applied to tributaries converging on Byrd Glacier, the same measurements can be conducted when tributaries pack together to become “flow stripes” down Byrd Glacier and onto the Ross Ice Shelf to see if (2) is reduced when lateral advection stops. This could determine if thermal convection remains active or shuts down as ice thins. Thermal convection in the Antarctic Ice Sheet would raise three questions. Can it cause the ice sheet to self-destruct as convective flow turns on and off? Does it render invalid climate records extracted at depth from ice cores? Can the ice sheet be studied as a miniature mantle analogous in some respects to Earth’s mantle?

关键词： Thermal Convection Antarctic Ice Sheet climate Change Rising Sea Level

Effect of climate Variability on Yams (<i>Dioscorea spp</i>.) Production in Central and Northern Benin

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American Journal of climate Change 2020年第4期9卷 423-440页

作者： Fiacre Hermann Adifon Gilbert Atindogbé Daouda Orou Bello Ibouraïman Balogoun Ibouraïma Yabi Joseph Dossou Léonard Ahoton Aliou Saïdou Integrated Soil and Crop Management (ISCM) Unit Soil Sciences Laboratory School of Plant Production Sciences and Techniques Faculty of Agronomic Sciences University of Abomey-Calavi Cotonou Benin laboratory of Study and Research in Applied and Biometric Statistics (LERSAB) Faculty of Agronomic Sciences (FSA) of the University of Abomey-Calavi Cotonou Benin Plant Biology laboratory School of Plant Production Sciences and Techniques Faculty of Agronomic Sciences University of Abomey-Calavi Cotonou Benin pierre pagney laboratory “climate Water Ecosystem and Development” University of Abomey-Calavi Faculty of Letters Arts and Human Sciences Department of Geography and Spatial Planning Cotonou Benin laboratory of Bioengineering of Food Processes (LABIOPA) Faculty of Agronomic Sciences (FSA) University of Abomey-Calavi Cotonou Benin

climate change poses an important constraint to agricultural sector and food security in tropical African countries dominated by rain-fed agriculture. This research focuses on the effects of climate variability on yam production in central and northern Benin. Daily climate data such as temperatures, precipitation, potential evapotranspiration, relative humidity and insolation from 1981 to 2016 were collected at the direction of METEO-Benin. A survey was then conducted with 351 producers to collect their perceptions of the effect of climate variability on the yams production. Descriptive statistics, principal component analysis (PCA) followed by trend analyses, Lamb index calculations and the agro-climatic stress index were carried out. The distribution of rain during the yam cycle (91.5% of those surveyed), the ambient temperature (84.9%), insolation (83.5%), the amount of rainwater that fell during the rainy season (82.2%) and the harmattan (53.3%) are perceived by sociolinguistic groups as climatic factors affecting the growth, the tuberization and yield of yams according to the producers. The results indicate an upward trend in temperature over the period 2001 to 2016 in the transition zone (28.4°C) and in the Northeast (27.76°C) and over the period from 2001 to 2011 in the North-West of Benin (27.71°C), where the average annual temperature during these periods is higher than normal (27.82°C in the center, 27.44°C in the Northeast and 27.42°C to the northwest). This research also shows an instability of the rains with a regular decrease in the rainfall in the Centre and the North-East of the country. The agro-climatic stress index (ISA) and above all the annual rainfall constitute the main climatic factors which determine

关键词： Yam climate Variability Yield Food Security Benin