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Multiscale spatiotemporal meteorological drought prediction:A deep learning approach

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Advances in Climate Change Research 2024年第2期15卷 211-221页

作者： Jia-Li ZHANG Xiao-Meng HUANG Yu-Ze SUN Department of earth system Science Ministry of Education Key Laboratory for Earth System ModellingInstitute for Global Change StudiesTsinghua UniversityBeijing 100084China

Reliable monitoring and thorough spatiotemporal prediction of meteorological drought are crucial for early warning and decision-making regarding drought-related disasters.The utilisation of multiscale methods is effective for a comprehensive evaluation of drought occurrence and progression,given the complex nature of meteorological drought.Nevertheless,the nonlinear spatiotemporal features of meteorological droughts,influenced by various climatological,physical and environmental factors,pose significant challenges to integrated prediction that considers multiple indicators and time scales.To address these constraints,we introduce an innovative deep learning framework based on the shifted window transformer,designed for executing spatiotemporal prediction of meteorological drought across multiple scales.We formulate four prediction indicators using the standardized precipitation index and the standard precipitation evaporation index as core methods for drought definition using the ERA5 reanalysis dataset.These indicators span time scales of approximately 30 d and one season.Short-term indicators capture more anomalous variations,whereas long-term indicators attain comparatively higher accuracy in predicting future trends.We focus on the East Asian region,notable for its diverse climate conditions and intricate terrains,to validate the model's efficacy in addressing the complexities of nonlinear spatiotemporal prediction.The model's performance is evaluated from diverse spatiotemporal viewpoints,and practical application values are analysed by representative drought events.Experimental results substantiate the effectiveness of our proposed model in providing accurate multiscale predictions and capturing the spatiotemporal evolution characteristics of drought.Each of the four drought indicators accurately delineates specific facets of the meteorological drought trend.Moreover,three representative drought events,namely flash drought,sustained drought and severe drought,underscore the significance of selecting appropr

关键词： Meteorological drought Spatiotemporal prediction Multiscale Swim transformer Deep learning

Applications of mercury stable isotopes for tracing volcanism in the geologic record

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Science China earth Sciences 2024年第5期67卷 1436-1458页

作者： Qing GONG Ming-Xing LING Wang ZHENG State Key Laboratory of Nuclear Resources and Environment East China University of TechnologyNanchang 330013China School of earth system Science Institute of Surface-Earth System ScienceTianjin UniversityTianjin 300072China

Mercury(Hg)enrichments in ancient sediments have been used as a proxy of volcanism,especially large igneous province(LIP)eruptions.However,considering the existence of other potential Hg sources besides volcanoes and the diverse factors(e.g.,organic matters,clay minerals,sulfide minerals and Fe oxides)that can affect Hg sequestration,there are considerable uncertainties to simply regard sedimentary Hg anomalies as signatures of volcanic activities.Mercury stable isotopes,a promising tool for tracing the origins and transformations of Hg,have been increasingly used for determining the causes of Hg spikes and understanding the geochemical behavior of Hg in the geologic record.To date,lots of researches have applied Hg concentrations and Hg isotopes to identify LIP volcanisms linking with significant geological events such as mass extinctions,ocean anoxic events and other environmental perturbations that mainly occurred in the Phanerozoic.However,the results in previous studies clearly show that not all Hg enrichments are derived from volcanic inputs,which emphasize the need for more caution in using Hg as a fingerprint of volcanism.With a better understanding of Hg isotopes in the future,there will be important implications for Hg isotopes to reconstruct volcanic activities in the rock records and their impacts on biological evolution.

关键词： Mercury stable isotopes Large igneous province Mass extinction event Ocean anoxic event

Influences of Graupel Microphysics on CMA-GFS Simulation of Summer Regional Precipitation

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Journal of Meteorological Research 2024年第1期38卷 27-38页

作者： Zhe LI Qijun LIU Zhanshan MA CMA earth system Modeling and Prediction Centre China Meteorological Administration(CMA)Beijing 100081

The horizontal resolution of global numerical weather prediction models is continuously developing. However, due to the imperfect precipitation simulation/forecast of these models, the demand for considering riming particles in cloud microphysical schemes in these models is increasing. This study employed the latest versions of global atmospheric reanalysis data (ERA5), the satellite retrieval data of the Global Precipitation Observation Program (GPM),and station precipitation observations to explore the impacts of adding graupel to the cloud microphysical scheme in the China Meteorological Administration-Global Forecast system (CMA-GFS) on summer regional precipitation simulations in four Chinese climate zones. The results verify that the new graupel scheme can enable CMA-GFS to decently predict global graupel distribution, especially in tropical and midlatitude regions. The addition of graupel in the cloud microphysics increases the precipitation simulation in North China, while that in Southwest China is weakened and dispersed. Moreover, graupel scheme increases the precipitation simulations of almost all magnitudes.The increase in light rain is obvious, and the absolute value of heavy rain is strengthened. This may be because graupel quickly melts into rain after falling out of the zero-temperature layer due to its large mass and fast falling speed, increasing surface precipitation. In summary, the addition of graupel in the cloud microphysical scheme can improve CMA-GFS’s underestimation of strong precipitation.

关键词： graupel cloud microphysical scheme precipitation China Meteorological Administration-Global Forecast system(CMA-GFS) climate zone

Analysis of amino acid enantiomers in ambient aerosols:Effects and removal of coexistent aerosol matrix

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Journal of Environmental Sciences 2024年第3期137卷 732-740页

作者： Ying Li Xiaoying Li Libin Wu Luhan Shi ShanWang Pingqing Fu Yingyi Zhang Senchao Lai The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters Ministry of EducationSchool of Environment and EnergySouth China University of TechnologyGuangzhou 510006China Institute of Surface-earth system Science School of Earth System ScienceTianjin UniversityTianjin 300072China now at Hong Kong University of Science and Technology Hong Kong 00852China

Amino acids(AAs)including D-and L-enantiomers are a group of organic nitrogen species in ambient aerosol.Due to the low abundances of AAs(level of ng/m^(3))and the matrix effects by coexistent components,it is challenging to quantify AA enantiomers in ambient aerosols especially under pollution conditions.In this study,we present an optimized method for analyzing AA enantiomers in atmospheric aerosol samples including a pretreatment process and the detection by high performance liquid chromatography coupled to a fuorescence detector(HPLC-FLD).Matrix effects caused by coexistent chemicals on AA enantiomers analysis in ambient aerosol samples were investigated especially for those collected in pollution episodes.The results revealed that the determination of AA enantiomers is significantly affected by the coexistent organic carbon(as a proxy of organic matter)and water-soluble ion of NH_(4)^(+).To remove the matrix effects,we applied a pretreatment using the solid phase extraction column coupled with alkaline adjustment to sample extract.After pretreatment,18 AAs including 6 pairs of D-and L-enantiomers(i.e.,leucine,isoleucine,valine,alanine,serine,and aspartic acid)can be successfully separated and quantified in aerosol samples by HPLC-FLD.The recoveries are in the range of 67%-106%.This method was successfully applied to the urban aerosol samples from pollution and non-pollution periods for AA enantiomers determination.We suggest that the concentrations of D-AAs and the ratio of D-AA/L-AA are indicative of the contribution of bacterial sources and the infuence of biomass burning.

关键词： Amino acid enantiomers Atmospheric aerosol Organic carbon Ammonia Chiral ratio

Does the continuous wetting of the Tibetan Plateau contribute to the accelerated degradation of permafrost?

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Science China earth Sciences 2024年第5期67卷 1714-1718页

作者： Yuyang WANG Jinzhi DING Shilong PIAO Sino-French Institute for earth system Science College of Urban and Environmental SciencesPeking UniversityBeijing 100871China State Key Laboratory of Tibetan Plateau earth system Environment and ResourcesInstitute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China

Global warming is causing the Tibetan permafrost to degrade, as evidenced by rising ground temperatures, thicker active layer thickness, thinner permafrost layer, and melting underground ice, etc.(Ran et al., 2018;Wang et al., 2020).The degradation of permafrost not only profoundly alters the carbon cycling processes in high-altitude ecosystems,thereby influencing the regional climate system, but also affects landscape hydrological connectivity。

关键词： Tibetan landscape altitude

Quick and automatic detection of co-seismic landslides with multifeature deep learning model

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Science China earth Sciences 2024年第7期67卷 2311-2325页

作者： Wenchao HUANGFU Haijun QIU Peng CUI Dongdong YANG Ya LIU Bingzhe TANG Zijing LIU Mohib ULLAH College of Urban and Environmental Sciences Northwest UniversityXi'an 710127China Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610041China Shaanxi Key Laboratory of earth Surface system and Environmental Carrying Capacity Northwest UniversityXi'an 710127China Institute of earth Surface system and Hazards Northwest UniversityXi'an 710127China

Co-seismic landslide detection is essential for post-disaster rescue and risk assessment after an earthquake event.However,a variety of ground objects,including roads and bare land,have spectral characteristics similar to those of co-seismic landslides,making it difficult to gather information and assess their impact rapidly and accurately.Therefore,an automatic detection method based on a deep learning model,named ENVINet5,with multiple features(ENVINet5_MF)was proposed to solve this problem and improve the detection accuracy of co-seismic landslides.The ENVINet5_MF method is advantageous for co-seismic landslide detection because it features a landslide gain index(LGI)that effectively eliminates the spectral interference of bare land and roads.We conducted two experiments using multi-temporal PlanetScope images acquired in Hokkaido,Japan,and Mainling,China.The accuracy evaluation and rationality analysis show that ENVINet5_MF performed better than comparative methods and that the co-seismic landslide areas detected by ENVINet5_MF were the most consistent with ground reference data.The findings of this study suggest that ENVINet5_MF can provide an efficient and accurate method for coseismic landslide detection to ensure a rapid response to co-seismic landslide disasters.

关键词： Co-seismic landslide Automatic detection Deep learning Landslide gain index PlanetScope images

Comparison of tropical cyclone thermal structures derived from ATMS and synthetic AMSU-A/MHS

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Atmospheric and Oceanic Science Letters 2024年第4期17卷 29-34页

作者： Wenyu Li Fuzhong Weng Chinese Academy of Meteorological Sciences BeijingChina Center for earth system Modeling and Prediction of CMA BeijingChina

热带气旋(TC)的暖心反映了其强度和变化.微波探测数据被广泛用于探测TC暖心,但观测到的TC暖心强度可能因仪器而异.本研究利用先进技术微波探测仪(ATMS)的过采样数据重采样至与先进微波探测仪(AMSU-A)一致的亮温,称为类AMSU数据.通过对... 详细信息

热带气旋(TC)的暖心反映了其强度和变化.微波探测数据被广泛用于探测TC暖心,但观测到的TC暖心强度可能因仪器而异.本研究利用先进技术微波探测仪(ATMS)的过采样数据重采样至与先进微波探测仪(AMSU-A)一致的亮温,称为类AMSU数据.通过对比发现,ATMS的观测更加细致,较好地刻画了TC眼区和云带.使用ATMS和类-AMSU数据反演多个TC的暖心发现,在250 hPa,使用ATMS数据反演的暖心强度比类-AMSU高约1-2K,并且其暖心结构更详细.

关键词：热带气旋暖心 ATMS AMSU-A 微波探测数据

Characterizing the behavior of surge-type glaciers in the Puruogangri Ice Field, Tibetan Plateau

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Journal of Geographical Sciences 2024年第6期34卷 1174-1194页

作者： ZHOU Sugang WANG Ninglian LI Zhijie YAO Xiaojun ZHANG Yuje QIN Gexia Shaanxi Key Laboratory of earth Surface system and Environmental Carrying Capacity College of Urban and Environmental SciencesNorthwest UniversityXi'an 710127China Institute of earth Surface system and Hazards College of Urban and Environmental SciencesNorthwest UniversityXi'an 710127China College of Geography and Environmental Science Northwest Normal UniversityLanzhou 730070China

The Puruogangri Ice Field(PIF), classified as an ultra-continental glacier, is considered extremely stable. However, several glaciers in this area have recently experienced surge events with significant instability and information on surge-type glaciers(STGs) in this region remains scarce. In this study, we identified six STGs and reported the observed characteristics of their surging behavior in the region by mapping glacier boundaries, surface flow velocity information, and glacier surface elevation changes using recent Landsat satellite imagery and shuttle radar topography mission(SRTM), TanDEM, and ASTER digital elevation model(AST14DEM) data. These data provide valuable insights into recent glacial processes, flow instability, and rapid glacial movement. During the active phase of the glaciers,all exhibited frontal advances and changes in surface elevation. Owing to limitations in the satellite imagery, flow velocity profiles were only available for glaciers N1(G089071E33998N),NE1(G089128E33943N), and SE3(G089278E33913N) during the active phase. However,these results effectively reflect the velocity variations in both glaciers before, during, and after the surge. Based on the characteristics of the STG, scientific expeditions, and meteorological data, we believe that the surge in PIF was largely influenced by glacier meltwater and changes in subglacial drainage systems.

关键词： glacier surge glacier surface elevation changes glacier surface velocity Puruogangri Ice Field

Holocene Hydroclimatic Variations in the Asian Drylands:Current Understanding and Future Perspectives

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Journal of earth Science 2024年第1期35卷 292-295页

作者： Guoqiang Ding Shengqian Chen Yuanhao Sun Shuai Ma Jianhui Chen MOE Key Laboratory of West China's Environmental system College of Earth and Environmental SciencesLanzhou UniversityLanzhou 730000China Alpine Paleoecology and Human Adaptation Group State Key Laboratory of Tibetan Plateau Earth SystemEnvironment and ResourcesInstitute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China

0 INTRODUCTION.The intensification of global warming is generating increasing risks to human society and sustainable development,which are of growing concern to the international scientific community and policymakers(Sun,2023).The ecosystems of the Asian drylands are fragile and highly sensitive to global changes;moreover,while these drylands are the most important areas of oasis agriculture on earth,their water resources are being adversely impacted by ongoing climate change(Zhang et al.,2023).Hence,an improved understanding of the patterns of climate change in this region is important and attracting increasing research attention.

关键词： Asian Holocene climatic