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Seismic and geological evidence of hidden faults in the Yinpan Reservoir area based on a dense seismic array

Science China earth Sciences 2024年第7期67卷 2401-2407页

作者： Guangyao YIN Huai ZHANG Liwen GONG Q ipeng BAI Yicun GUO Bing ZHANG Yaolin SHI Key Laboratoryof Earth System Numerical Modeling and Application(Chinese Academyof Sciences) College of Earth and Planetary SciencesUniversity of Chinese Academy of SciencesBeijing 100049China Key Laboratory of Computational Geodynamics Chinese Academy of SciencesBeijing 100049China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519080China Beijing Yanshan Critical Zone National Field Scientific Observation and Research Station Beijing 101408China Chongqing Earthquake Agency Chongqing 401147 China Institute of Earthquake Forecasting China Earthquake AdministrationBeijing 100036China Hangzhou Applied Acoustics Research Institute Hangzhou 311100China State Key Laboratory of Geodesy and Earths Dynamics Innovation Academy for Precision Measurement Science and TechnologyCASWuhan 430077China

*** November 23,2017,an M_(S)5.0 earthquake occurred in Wulong,Chongqing,China,resulting in tens of casualties and considerable economic ***,the epicenter of this earthquake was located in the transition zone from the... 详细信息

关键词： earthquake southeast seismic

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Meridional Displacement of the East Asian Upper-tropospheric Westerly Jet and Its Relationship with the East Asian Summer Rainfall in CMIP5 Simulations

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Advances in Atmospheric Sciences 2019年第11期36卷 1203-1216页

作者： Yuhan YAN Chaofan LI Riyu LU State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China College of Earth and Planetary Sciences University of the Chinese Academy of Sciences Beijing 100029 China Center for Monsoon System Research Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

As the first leading mode of upper-tropospheric circulation in observations, the meridional displacement of the East Asian westerly jet (EAJ) varies closely with the East Asian rainfall in summer. In this study, the interannual variation of the EAJ meridional displacement and its relationship with the East Asian summer rainfall are evaluated, using the historical simulations of CMIP5 (phase 5 of the Coupled Model Intercomparison Project). The models can generally reproduce the meridional displacement of the EAJ, which is mainly manifested as the first principal mode in most of the simulations. For the relationship between the meridional displacement of the EAJ and East Asian rainfall, almost all the models depict a weaker correlation than observations and exhibit considerably large spread across the models. It is found that the discrepancy in the interannual relationship is closely related to the simulation of the climate mean state, including the climatological location of the westerly jet in Eurasia and rainfall bias in South Asia and the western North Pacific. In addition, a close relationship between the simulation discrepancy and intensity of EAJ variability is also found: the models with a stronger intensity of the EAJ meridional displacement tend to reproduce a closer interannual relationship, and vice versa.

关键词： East Asian westerly jet meridional teleconnection East Asian rainband model simulation

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Differences and Links between the East Asian and South Asian Summer Monsoon systems:Characteristics and Variability

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Advances in Atmospheric Sciences 2017年第10期34卷 1204-1218页

作者： Ronghui HUANG Yong LIU Zhencai DU Jilong CHEN Jingliang HUANGFU Center for Monsoon System Research Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100190China State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of ScienceBeijing 100029China Institute of Earth Sciences University of Chinese Academy of SciencesBeijing 100049China

This paper analyzes the differences in the characteristics and spatio–temporal variabilities of summertime rainfall and water vapor transport between the East Asian summer monsoon（EASM） and South Asian summer monsoon（SASM） systems. The results show obvious differences in summertime rainfall characteristics between these two monsoon systems. The summertime rainfall cloud systems of the EASM show a mixed stratiform and cumulus cloud system, while cumulus cloud dominates the SASM. These differences may be caused by differences in the vertical shear of zonal and meridional circulations and the convergence of water vapor transport fluxes. Moreover, the leading modes of the two systems＇ summertime rainfall anomalies also differ in terms of their spatiotemporal features on the interannual and interdecadal timescales. Nevertheless, several close links with respect to the spatiotemporal variabilities of summertime rainfall and water vapor transport exist between the two monsoon systems. The first modes of summertime rainfall in the SASM and EASM regions reveal a significant negative correlation on the interannual and the interdecadal timescales. This close relationship may be linked by a meridional teleconnection in the regressed summertime rainfall anomalies from India to North China through the southeastern part over the Tibetan Plateau, which we refer to as the South Asia/East Asia teleconnection pattern of Asian summer monsoon rainfall. The authors wish to dedicate this paper to Prof. Duzheng YE, and commemorate his 100 thanniversary and his great contributions to the development of atmospheric dynamics.

关键词： East Asian summer monsoon South Asian summer monsoon spatiotemporal variability rainfall water vapor transport

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Reducing the climate shift in a new coupled model

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Science Bulletin 2016年第12期61卷 488-494页

作者： Yanli Tang Lijuan Li Wenjie Dong Bin Wang State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG) Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029 China School of Atmospheric Sciences Sun Yat-sen UniversityZhuhai 519082 China CAS Center for Excellent in Tibetan Plateau Earth Sciences Beijing 100101 China Ministry of Education Key Laboratory for Earth System Modeling Center of Earth System Science (CESS)Tsinghua University Beijing 100084 China

Climate drift refers to spurious long-term changes that may be inherent in coupled models when external forcing factors are fixed. Understanding the sources of this drift and tuning the drift are crucial for obtaining reasonable simulations from coupled models. To prepare for the upcoming Coupled Model Intercomparison Project Phase 6, a new coupled model has been constructed based on the Community earth system Model and the Grid-point Atmospheric Model of IAP LASG version 2. However, the surface temperature predicted by the new model is too underestimated, and this underestimation is caused by a type of climate drift, i.e., ‘‘initial shock.'' This study analyzes the source of the cold surface temperature from the perspective of energy balance and attempts to reduce the surface temperature drift by tuning the relative humidity threshold for low cloud.

关键词： Climate drift CESM–GAMIL2 Initial shock Relative humidity threshold

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Strengthening of the annual temperature cycle in the mid-latitudes of Northern Hemisphere

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Discover Geoscience 2024年第1期2卷 1-6页

作者： Tang, Tao Lee, Xuhui Cao, Junji Science Center for Earth System Numerical Simulation Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China Key Laboratory of Earth System Numerical Modeling and Application Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China School of the Environment Yale University New Haven USA

The annual temperature cycle (ATC), defined as the surface temperature difference between summer and winter, plays a crucial role in controlling the phenology of biological systems (Sparks and Menzel in Int J Climatol 22(14):1715–25, 2002) and in global and regional circulation patterns (Schott and McCreary in Prog Oceanogr 51(1):1–123, 2001), (Adam et al. in J Clim 29(9): 3219–3230, 2016). Contrary to previous studies which report a decreasing trend in the ATC worldwide (Mann and Park in Geophys Res Lett 23(10):1111–4, 1996), (Wallace and Osborn in Climate Res 22(1):1–11, 2002), recent studies suggest an increasing ATC trend in the mid-latitude regions (Wang and Dillon in Nat Clim Chang 4(11):988–92, 2014). Although the trend may bear anthropogenic fingerprints, the underlying mechanism remains elusive. Using atmospheric reanalysis data and observational records, we confirm that the increasing trend in the ATC occurred during 1980–2020, mainly in the West North America, Mediterranean region and part of North Asia. The main driver of this ATC change is the faster increase in the incoming radiation on the land surface in the summer as a result of the buildup of water vapor and reduction in cloudiness. This increase was further amplified by continental dryness in the summer.

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CONDITIONAL NONLINEAR OPTIMAL PERTURBATIONS: application IN TROPICAL CYCLONE FORECASTS

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Journal of Tropical Meteorology 2019年第4期25卷 421-436页

作者： TIAN Hong-jun LI Ze-chun WANG Dong-liang WANG Bin Nanjing University of Information Science and Technology Nanjing 210044 China Shanghai Central Meteorological Observatory Shanghai 200030 China National Meteorological Centre Beijing 100081 China Shanghai Typhoon Institute CMAShanghai 200030 China State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of ScienceBeijing 100029 China Ministry of Education Key Laboratory for Earth System Modeling Tsinghua UniversityBeijing 100084 China

Considering the feature of tropical cyclones(TCs) that strong positive vorticity exists in the lower layers of troposphere, this study proposed to use vorticity at 850 hPa as cost function to find the conditional nonlinear optimal perturbation(CNOP), which was largely different from previous studies using total energy of perturbed forecast variables. The CNOP was obtained by an ensemble-based approach. All of the sensitive areas determined by CNOP with vorticity at 850 hPa as cost function for the three cases were located over the TC core region and its vicinity. The impact of the CNOP-based adaptive observations on TC forecasts was evaluated with three cases via observational system simulation experiments(OSSEs). Results showed obvious improvements in TC intensity or track forecasts due to the CNOP-based adaptive observations, which were related to the main error source of the verification area, i.e.,intensity error or location error.

关键词： conditional nonlinear optimal perturbations tropical cyclone intensity track

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Comparison of Nonlinear Local Lyapunov Vectors with Bred Vectors, Random Perturbations and Ensemble Transform Kalman Filter Strategies in a Barotropic Model

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Advances in Atmospheric Sciences 2016年第9期33卷 1036-1046页

作者： Jie FENG Ruiqiang DING Jianping LI Deqiang LIU State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029 College of Earth Science University of Chinese Academy of SciencesBeijing 100049 Global Systems Division Earth System Research Laboratory/Oceanic and Atmospheric Research/National Oceanic and Atmospheric AdministrationBoulderCO80305USA Plateau Atmosphere and Environment Key Laboratory of Sichuan Province Chengdu University of Information TechnologyChengdu 610225 College of Global Change and Earth System Sciences Beijing Normal UniversityBeijing 100875 Joint Center for Global Change Studies Beijing 100875 Fujian Meteorological Observatory Fuzhou 350001

The breeding method has been widely used to generate ensemble perturbations in ensemble forecasting due to its simple concept and low computational cost. This method produces the fastest growing perturbation modes to catch the growing components in analysis errors. However, the bred vectors （BVs） are evolved on the same dynamical flow, which may increase the dependence of perturbations. In contrast, the nonlinear local Lyapunov vector （NLLV） scheme generates flow-dependent perturbations as in the breeding method, but regularly conducts the Gram-Schmidt reorthonormalization processes on the perturbations. The resulting NLLVs span the fast-growing perturbation subspace efficiently, and thus may grasp more com- ponents in analysis errors than the BVs. In this paper, the NLLVs are employed to generate initial ensemble perturbations in a barotropic quasi-geostrophic model. The performances of the ensemble forecasts of the NLLV method are systematically compared to those of the random pertur- bation （RP） technique, and the BV method, as well as its improved version--the ensemble transform Kalman filter （ETKF） method. The results demonstrate that the RP technique has the worst performance in ensemble forecasts, which indicates the importance of a flow-dependent initialization scheme. The ensemble perturbation subspaces of the NLLV and ETKF methods are preliminarily shown to catch similar components of analysis errors, which exceed that of the BVs. However, the NLLV scheme demonstrates slightly higher ensemble forecast skill than the ETKF scheme. In addition, the NLLV scheme involves a significantly simpler algorithm and less computation time than the ETKF method, and both demonstrate better ensemble forecast skill than the BV scheme.

关键词： ensemble forecasting bred vector nonlinear local Lyapunov vector ensemble transform Kalman filter

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A Machine Learning-Based Observation Operator for FY-4B GIIRS Brightness Temperatures Considering the Uncertainty of Label Data

Journal of Geophysical Research: Machine Learning and Comput...

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Journal of Geophysical Research: Machine Learning and Computation 2025年第1期2卷

作者： Yonghui Li Wei Han Wansuo Duan Zeting Li Hao Li State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China University of Chinese Academy of Sciences Beijing China State Key Laboratory of Severe Weather Meteorological Science and Technology (LASW) Beijing China CMA Earth System Modeling and Prediction Centre (CEMC) China Meteorological Administration Beijing China Key Laboratory of Meteorological Disaster Ministry of Education (KLME)/Joint International Research Laboratory of Climate and Environment Change (ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD) Nanjing University of Information Science & Technology Nanjing China Artificial Intelligence Innovation and Incubation Institute Fudan University Shanghai China Shanghai Academy of Artificial Intelligence for Science (SAIS) Shanghai China

The increasing volume of satellite data, particularly hyperspectral infrared data, combined with the real-time monitoring requirements of numerical weather prediction (NWP) systems, has heightened the demand for computational efficiency and accuracy in radiative transfer models (RTM). Machine learning (ML) offers a promising approach, and numerous studies on ML-based RTM have emerged recently. However, existing ML-based RTMs for hyperspectral infrared were not end-to-end. Moreover, since the label data do not represent truth, models trained with loss functions like mean squared error (MSE) or mean absolute error (MAE) fail to account for its uncertainty. This limitation can lead to suboptimal model parameters, as training may assign higher weights to labels with larger errors. This study construct an end-to-end ML-based RTM focused on clear sky conditions over the ocean for the FengYun-4B satellite (FY-4B) Geostationary Interferometric Infrared Sounder (GIIRS), using maximum likelihood estimation (MLE) and MSE for training, respectively. MLE accounts for the uncertainty of labels. The results indicate both models achieve high accuracy, with mean errors within 0.1 K (K) and standard deviation (STD) of errors within 0.04 K compared to the labels. The model trained with MLE exhibits a mean error closer to 0 and a STD similar to the error STD of labels, suggesting better parameter configurations to reflect the actual error distribution of the labels. Additionally, the temperature and water vapor Jacobian computed by both models are comparable to those obtained from RTTOV, highlighting their potential for application as observational operator in satellite data assimilation for hyperspectral infrared sounder. An end-to-end machine learning-based radiative transfer model for clear sky has been developed for FY-4B GIIRS The model, trained using a likelihood-based loss function that weights each channel differently, captures the uncertainty of labels The Jacobian matrix calc

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The Characteristics of Mesoscale Convective systems (MCSs) over East Asia in Warm Seasons

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Atmospheric and Oceanic Science Letters 2012年第2期5卷 102-107页

作者： Li Jun Wang Bin Wang Dong-Hai State Key Laboratory of Numerical modeling for Atmospheric Science and Geophysical Fluid Dynamics (LASG) Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Center for Earth System Science Tsinghua University Beijing 100084 China State Key Laboratory of Severe Weather Chinese Academy of Meteorology Beijing 100081 China

Mesoscale convective system (MCS) cloud clusters,defined using an objective recognition analysis based on hourly geostationary infrared satellite data over East Asia during the warm seasons of 1996-2008 (except 2004),were investigated in this *** geographical pattern of MCS distribution over East Asia shows several high-frequency centers at low latitudes,including the Indo-China peninsula,the Bay of Bengal,the Andaman Sea,the Brahmaputra river delta,the south China coastal region,and the Philippine *** are several middle-frequency centers in the middle latitudes,e.g.,the central-east of the Tibet Plateau,the Plateau of west Sichuan,Mount Wuyi,and the Sayan Mountains in Russia;whereas in Lake Baikal,the Tarim Basin,the Taklimakan Desert,the Sea of Japan,and the Sea of Okhotsk,rare MCS distributions are *** are most intensely active in summer,with the highest monthly frequency in July,which is partly associated with the breaking out and prevailing of the summer monsoon in East *** obvious diurnal cycle feature is also found in MCS activities,which shows that MCSs are triggered in the afternoon,mature in the evening,and dissipate at *** patterns over East Asia can be characterized as small,short-lived,or elongated,which move slowly and usually lead to heavy rains or floods.

关键词： Mesoscale Convective system infrared satellite data distribution monthly variation diurnal cycle

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Synergistic Contribution of Precipitation Anomalies over Northwestern India and the South China Sea to High Temperature over the Yangtze River Valley

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Advances in Atmospheric Sciences 2015年第9期32卷 1255-1265页

作者： LIU Ge WU Renguang SUN Shuqing WANG Huimei Chinese Academy of Meteorological Sciences Institute of Space and Earth Information Science/Department of Geography and Resource Management/Shenzhen Research Institute Chinese University of Hong Kong Center for Monsoon System Research Institute of Atmospheric PhysicsChinese Academy of Sciences State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of Sciences

This study explores the characteristics of high temperature anomalies over eastern China and associated influencing factors using observations and model *** show that more long-duration（over 8 days） high temperature events occur over the middle and lower reaches of the Yangtze River Valley（YRV） than over the surrounding regions,and control most of the interannual variation of summer mean temperature in *** synergistic effect of summer precipitation over the South China Sea（SCS） region（18°–27°N,115°–124°E） and the northwestern India and Arabian Sea（IAS） region（18°–27°N,60°–80°E） contributes more significantly to the variation of summer YRV temperature,relative to the respective SCS or IAS precipitation *** precipitation（enhanced condensational heating） over the SCS region strengthens the western Pacific subtropical high（WPSH） and simultaneously weakens the westerly trough over the east coast of Asia,and accordingly results in associated high temperature anomalies over the YRV region through stimulating an East Asia–Pacific（EAP） *** precipitation over the IAS region further adjusts the variations of the WPSH and westerly trough,and eventually reinforces high temperature anomalies over the YRV ***,the condensational heating related to more IAS precipitation can adjust upper-tropospheric easterly anomalies over the YRV region by exciting a circumglobal teleconnection,inducing cold horizontal temperature advection and related anomalous descent,which is also conducive to the YRV high temperature *** reproduction of the above association in the model results indicates that the above results can be explained both statistically and dynamically.

关键词： high temperature events Yangtze River Valley precipitation ECHAM5

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