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Assessment of Interannual Sea Surface Salinity Variability and Its Effects on the Barrier Layer in the Equatorial Pacific Using BNU-ESM

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Advances in Atmospheric Sciences 2016年第3期33卷 339-351页

作者： Hai ZHI Rong-Hua ZHANG Fei ZHENG Pengfei LIN Lanning WANG Peng YU Earth System Modeling Center and College of Atmospheric Sciences Nanjing University of Information Science and Technology Key Laboratory of Ocean Circulation and Waves Institute of OceanologyChinese Academy of Sciences International Center for Climate and Environment Science 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 College of Global Change and Earth System Science Beijing Normal University Cooperative Institute for Climate and Satellites University of MarylandCollege Park

As salinity stratification is necessary to form the barrier layer （BL）, the quantification of its role in BL interannual variability is crucial. This study assessed salinity variability and its effect on the BL in the equatorial Pacific using outputs from Beijing Normal University earth system Model （BNU-ESM） simulations. A comparison between observations and the BNU-ESM simulations demonstrated that BNU-ESM has good capability in reproducing most of the interannual features observed in nature. Despite some discrepancies in both magnitude and location of the interannual variability centers, the displacements of sea surface salinity （SSS）, barrier layer thickness （BLT）, and SST simulated by BNU-ESM in the equatorial Pacific are realistic. During E1 Nifio, for example, the modeled interannual anomalies of BLT, mixed layer depth, and isothermal layer depth, exhibit good correspondence with observations, including the development and decay of E1 Nifio in the central Pacific, whereas the intensity of the interannual variabilities is weaker relative to observations. Due to the bias in salinity simulations, the SSS front extends farther west along the equator, whereas BLT variability is weaker in the central Pacific than in observations. Further, the BNU-ESM simulations were examined to assess the relative effects of salinity and temperature variability on BLT. Consistent with previous observation-based analyses, the interannual salinity variability can make a significant contribution to BLT relative to temperature in the western-central equatorial Pacific.

关键词： feedback interannual variability sea surface salinity barrier layer thickness

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A Theoretical Explanation of Anomalous Atmospheric Circulation Associated with ENSO Modoki during Boreal Winter

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Atmospheric and Oceanic Science Letters 2014年第4期7卷 352-357页

作者： XING Nan LI Jian-Ping LI Yao-Kun State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences University of the Chinese Academy of Sciences College of Global Change and Earth System Science Beijing Normal University

Based on a linear model, the present study provides analytical solutions for ideal triple forcing sources similar to sea surface temperature anomaly （SSTA） pat- terns associated with El Nino-Southern Oscillation （ENSO） Modoki in winter. The ideal triple pattern is composed of an equatorially symmetric heat source in the middle and equatoriaUy asymmetric cold forcing in the southeast and northwest. The equatorially symmetric heat source excites low-level cyclonic circulation anomalies associated with Rossby waves in both hemispheres, while the northwest- ern and southeastern equatorially asymmetric cold sources induce low-level anomalous anticyclones associated with Rossby waves in the hemisphere where the forcing source is located. Low-level zonal winds converge toward the heat sources associated with Kelvin and Rossby waves. Due to unequal forcing intensity in the northwest and southeast, atmospheric responses around the equatorially symmetric forcing become asymmetric, and low-level cyclonic circulation anomalies in the Southern Hemisphere become greater than those in the Northern Hemisphere. Ascending （descending） flows coincide with heat （cold） sources, resulting in a double-cell structure over the regions of forcing sources. Ideal triple patterns similar to SSTA patterns associated with La Nina Modoki produce opposite atmospheric responses. The theoretical atmospheric responses are consistent with observed circulation anomalies associated with ENSO Modoki. Therefore, the theoretical solutions can explain the dynamics responsible for atmospheric circulation anomalies associated with ENSO Modoki events.

关键词： external forcing sources atmospheric responses ENSO Modoki

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Assimilating the LAI Data to the VEGAS Model Using the Local Ensemble Transform Kalman Filter: An Observing system Simulation Experiment

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Atmospheric and Oceanic Science Letters 2014年第4期7卷 314-319页

作者： JIA Bing-Hao Ning ZENG XIE Zheng-Hui State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG) Institute of Atmospheric Physics Chinese Academy of Sciences Department of Atmospheric and Oceanic Science & Earth System Science Interdisciplinary Center University of Maryland College Park

Information on the spatial and temporal patterns of surface carbon flux is crucial to understanding of source/sink mechanisms and projection of future atmospheric CO2 concentrations and climate. This study presents the construction and implementation of a terrestrial carbon cycle data assimilation system based on a dynamic vegetation and terrestrial carbon model Vegetation-Global-Atmosphere-Soil(VEGAS) with an advanced assimilation algorithm, the local ensemble transform Kalman filter(LETKF, hereafter LETKF-VEGAS). An observing system simulation experiment(OSSE) framework was designed to evaluate the reliability of this system, and numerical experiments conducted by the OSSE using leaf area index(LAI) observations suggest that the LETKF-VEGAS can improve the estimations of leaf carbon pool and LAI significantly, with reduced root mean square errors and increased correlation coefficients with true values, as compared to a control run without assimilation. Furthermore, the LETKF-VEGAS has the potential to provide more accurate estimations of the net primary productivity(NPP) and carbon flux to atmosphere(CFta).

关键词： carbon cycle data assimilation VEGAS,land-atmosphere CO2 flux LETKF OSSE

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Intermodel Diversity of Simulated Long-term Changes in the Austral Winter Southern Annular Mode:Role of the Southern Ocean Dipole

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Advances in Atmospheric Sciences 2021年第3期38卷 375-386页

作者： Fei ZHENG Jianping LI Shuailei YAO State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 10029China Frontiers Science Center for Deep Ocean Multispheres and Earth System(FDOMES)/Key Laboratory of Physical Oceanography/Institute for Advanced Ocean Studies Ocean University of ChinaQingdao 266100China Laboratory for Ocean Dynamics and Climate Pilot Qingdao National Laboratory for Marine Science

The Southern Annular Mode(SAM)plays an important role in regulating Southern Hemisphere extratropical ***-of-the-art models exhibit intermodel spread in simulating long-term changes in the *** from Atmospheric Model Intercomparison Project(AMIP)experiments from 28 models archived in CMIP5 show that the intermodel spread in the linear trend in the austral winter(June−July−August)SAM is significant,with an intermodel standard deviation of 0.28(10 yr)−1,larger than the multimodel ensemble mean of 0.18(10 yr)−*** study explores potential factors underlying the model difference from the aspect of extratropical sea surface temperature(SST).Extratropical SST anomalies related to the SAM exhibit a dipole-like structure between middle and high latitudes,referred to as the Southern Ocean Dipole(SOD).The role of SOD-like SST anomalies in influencing the SAM is found in the AMIP *** performance in simulating the SAM trend is linked with model skill in reflecting the SOD−SAM *** with stronger linkage between the SOD and the SAM tend to simulate a stronger SAM *** explained variance is about 40%in the AMIP *** results suggest improved simulation of the SOD−SAM relationship may help reproduce long-term changes in the SAM.

关键词： Southern Annular Mode Southern Ocean Dipole intermodel spread air−sea interactions

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Pathways of Influence of the Northern Hemisphere Mid–high Latitudes on East Asian Climate: A Review

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Advances in Atmospheric Sciences 2019年第9期36卷 902-921页

作者： Jianping LI Fei ZHENG Cheng SUN Juan FENG Jing WANG Key Laboratory of Physical Oceanography–Institute for Advanced Ocean Studies Ocean University of China and Qingdao National Laboratory for Marine Science and TechnologyQingdao 266003China College of Global Change and Earth System Science Beijing Normal UniversityBeijing 100875China State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

This paper reviews recent progress made by Chinese scientists on the pathways of influence of the Northern Hemisphere mid-high latitudes on East Asian climate within the framework of a“coupled oceanic-atmospheric(land-atmospheric or seaice-atmospheric)bridge”and“chain coupled bridge”.Four major categories of pathways are concentrated upon,as follows:Pathway A—from North Atlantic to East Asia;Pathway B—from the North Pacific to East Asia;Pathway C—from the Arctic to East Asia;and Pathway D—the synergistic effects of the mid-high latitudes and *** addition,definitions of the terms“combined effect”,“synergistic effect”and“antagonistic effect”of two or more factors of influence or processes and their criteria are introduced,so as to objectively investigate those effects in future research.

关键词： East Asian climate Northern Hemisphere mid-high latitudes coupled oceanic-land-sea-ice-atmospheric bridge chain coupled bridge pathway synergistic effect

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application of a Neural Network to Store and Compute the Optical Properties of Non-Spherical Particles

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Advances in Atmospheric Sciences 2022年第12期39卷 2024-2039页

作者： Jinhe YU Lei BI Wei HAN Xiaoye ZHANG Key Laboratory of Geoscience Big Data and Deep Resource of Zhejiang Province School of Earth SciencesZhejiang UniversityHangzhou 310027China Center for Earth System Modeling and Prediction China Meteorological AdministrationBeijing 100081China Numerical Weather Prediction Center China Meteorological AdministrationBeijing 100081China Key Laboratory of Atmospheric Chemistry of China Meteorological Administration Institute of Atmospheric CompositionChinese Academy of Meteorological SciencesBeijing 100081China

Radiative transfer simulations and remote sensing studies fundamentally require accurate and efficient computation of the optical properties of non-spherical *** paper proposes a deep learning(DL)scheme in conjunction with an optical property database to achieve this *** neural network(DNN)architectures were obtained from a dataset of the optical properties of super-spheroids with extensive shape parameters,size parameters,and refractive *** dataset was computed through the invariant imbedding T-matrix *** separate DNN architectures were created to compute the extinction efficiency factor,single-scattering albedo,asymmetry factor,and phase *** criterion for designing these neural networks was the achievement of the highest prediction accuracy with minimal DNN *** numerical results demonstrate that the determination coefficients are greater than 0.999 between the prediction values from the neural networks and the truth values from the database,which indicates that the DNN can reproduce the optical properties in the dataset with high *** addition,the DNN model can robustly predict the optical properties of particles with high accuracy for shape parameters or refractive indices that are unavailable in the ***,the ratio of the database size(~127 GB)to that of the DNN parameters(~20 MB)is approximately 6810,implying that the DNN model can be treated as a highly compressed database that can be used as an alternative to the original database for real-time computing of the optical properties of non-spherical particles in radiative transfer and atmospheric models.

关键词： non-spherical particles light scattering super-spheroid model deep learning neural network

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Relationships among the Monsoon-like Southwest Australian Circulation,the Southern Annular Mode, and Winter Rainfall over Southwest Western Australia

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Advances in Atmospheric Sciences 2015年第8期32卷 1063-1076页

作者： FENG Juan LI Jianping Yun LI ZHU Jianlei XIE Fei College of Global Change and Earth System Science Beijing Normal University State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Joint Center for Global Change Studies Data Analytics CSIRO Digital Productivity Flagship Floreat6083 Western Australia Australia

This study examines the relationships among the monsoon-like southwest Australian circulation （SWAC）, the South- ern Annular Mode （SAM）, and southwest Western Australia winter rainfall （SWR）, based on observed rainfall, reanalysis datasets, and the results of numerical modeling. By decomposing the SWAC into two components using a linear model, i.e. the component related to SAM （RSAM） and the component unrelated to SAM （SWACI＊）, we find it is the SWACI＊ that shows a significant influence on SWR. Similarly, it is the component of SAM associated with SWAC that exhibits an impact on SWR, whereas the component unrelated to SAM. A similar result is obtained in terms of the circulation associated with SWAC and the SAM. These facts suggest the SAM plays an indirect role in influencing SWR, and raise the possibility that SWAC acts as a bridge between the SAM and SWR, by which the SAM passes its influences onto SWR. This is due to the fact that the variations of SWAC are closely linked to the thermal contrast between land and sea across the southern Indian Ocean and southwest Australia. By contrast, the SAM does not significantly relate to this thermal structure, particularly for the component unrelated to SWAC. The variations of surface sea temperature over the southern Indian Ocean contribute to the favored rainfall circulation patterns. This finding is supported by the numerical modeling results. The strong coupling between SWAC and SWR may be instrumental for understanding the interactions between SWR and the southern Indian Ocean, and provides another perspective in examining the variations in SWR.

关键词： monsoon-like Southwest Australian Circulation Southern Annular Mode southwest Western Australian winterrainfall

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Simulation of the Equatorially Asymmetric Mode of the Hadley Circulation in CMIP5 Models

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Advances in Atmospheric Sciences 2015年第8期32卷 1129-1142页

作者： FENG Juan LI Jianping ZHU Jianlei LI Fei SUN Cheng College of Global Change and Earth System Science Beijing Normal University State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Joint Center for Global Change Studies Department of Lower Atmosphere Observation Research Institute of Atmospheric PhysicsChinese Academy of Sciences

The tropical Hadley circulation （HC） plays an important role in influencing the climate in the tropics and extra-tropics. The realism of the climatological characteristics, spatial structure, and temporal evolution of the long-term variation of the principal mode of the annual mean HC （i.e., the equatorially asymmetric mode, EAM） was examined in model simulations from the Coupled Model Intercomparison Project Phase 5 （CMIP5）. The results showed that all the models are moderately successful in capturing the HC＇s climatological features, including the spatial pattern, meridional extent, and intensity, but not the spatial or temporal variation of the EAM. The possible reasons for the poor simulation of the long-term variability of the EAM were explored. None of the models can successfully capture the differences in the warming rate between the tropical Southern Hemisphere （SH） and Northern Hemisphere （NH）, which is considered to be an important driver for the variation of the AM. Most of the models produce a faster warming in the NH than in the SH, which is the reverse of the observed trend. This leads to a reversed trend in the meridional gradient between the SH and NH, and contributes to the poor simulation of EAM variability. Thus, this aspect of the models should be improved to provide better simulations of the variability of the HC. This study suggests a possible reason for the poor simulation of the HC, which may be helpful for improving the skill of the CMIP5 models in the future.

关键词： tropical Hadley circulation equatorially asymmetric mode CMIP5 sea surface temperature

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Influence of the NAO on Wintertime Surface Air Temperature over East Asia:Multidecadal Variability and Decadal Prediction

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Advances in Atmospheric Sciences 2022年第4期39卷 625-642页

作者： Jianping LI Tiejun XIE Xinxin TANG Hao WANG Cheng SUN Juan FENG Fei ZHENG Ruiqiang DING Frontiers Science Center for Deep Ocean Multispheres and Earth System-Key Laboratory of Physical Oceanography-Institute for Advanced Ocean Studies-Academy of the Future Ocean Ocean University of ChinaQingdao 266100China Laboratory for Ocean Dynamics and Climate Pilot Qingdao National Laboratory for Marine Science and TechnologyQingdao 266237China College of Global Change and Earth System Sciences Beijing Normal UniversityBeijing 100875China State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal UniversityBeijing 100875China

In this paper,we investigate the influence of the winter NAO on the multidecadal variability of winter East Asian surface air temperature(EASAT)and EASAT decadal *** observational analysis shows that the winter EASAT and East Asian minimum SAT(EAmSAT)display strong in-phase fluctuations and a significant 60-80-year multidecadal variability,apart from a long-term warming *** winter EASAT experienced a decreasing trend in the last two decades,which is consistent with the occurrence of extremely cold events in East Asia winters in recent *** winter NAO leads the detrended winter EASAT by 12-18 years with the greatest significant positive correlation at the lead time of 15 *** analysis shows that ENSO may affect winter EASAT interannual variability,but does not affect the robust lead relationship between the winter NAO and *** present the coupled oceanic-atmospheric bridge(COAB)mechanism of the NAO influences on winter EASAT multidecadal variability through its accumulated delayed effect of~15 years on the Atlantic Multidecadal Oscillation(AMO)and Africa-Asia multidecadal teleconnection(AAMT)*** NAO-based linear model for predicting winter decadal EASAT is constructed on the principle of the COAB mechanism,with good hindcast *** winter EASAT for 2020-34 is predicted to keep on fluctuating downward until~2025,implying a high probability of occurrence of extremely cold events in coming winters in East Asia,followed by a sudden turn towards sharp *** predicted 2020/21 winter EASAT is almost the same as the 2019/20 winter.

关键词： winter East Asian surface air temperature North Atlantic Oscillation Atlantic Multidecadal Oscillation Africa-Asia multidecadal teleconnection pattern coupled oceanic-atmospheric bridge multidecadal variability

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Prediction of ENSO using multivariable deep learning

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Atmospheric and Oceanic Science Letters 2023年第4期16卷 51-56页

作者： Yue Chen Xiaomeng Huang Jing-Jia Luo Yanluan Lin Jonathon S.Wright Youyu Lu Xingrong Chen Hua Jiang Pengfei Lin Ministry of Education Key Laboratory for Earth System Modeling and Department for Earth System Science Tsinghua UniversityBeijingChina Institute for Climate and Application Research(ICAR)/CICFEM/KLME/ILCEC Nanjing University of Information Science and TechnologyNanjingChina Ocean and Ecosystem Sciences Division Fisheries and Oceans CanadaBedford Institute of OceanographyDartmouthNova ScotiaCanada National Marine Environmental Forecasting Center State Oceanic AdministrationBeijingChina State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina

本文基于残差神经网络和观测数据构建了一套深度学习多因子预报测模型,以改进厄尔尼诺-南方涛动(ENSO)的预报.该模型基于最大信息系数进行因子时空特征提取,并根据泰勒图的评估标准可自动确定关键预报因子进行预报.该模型在超前8个月以... 详细信息

本文基于残差神经网络和观测数据构建了一套深度学习多因子预报测模型,以改进厄尔尼诺-南方涛动(ENSO)的预报.该模型基于最大信息系数进行因子时空特征提取,并根据泰勒图的评估标准可自动确定关键预报因子进行预报.该模型在超前8个月以内的预报性能要优于当前传统的业务预报模式.2011–2018年间,该模型的预报性能优于多模式集成预报的结果.在超前6个月预报时效上,模型预报相关性可达0.82,标准化后的均方根误差仅为0.58°C,多模式集成预报的相关性和标准化后的均方根误差分别为0.70和0.73°C.该模型春季预报障碍问题有所缓解,并且自动选取的关键预报因子可用于解释热带和副热带热动力过程对于ENSO变化的影响.

关键词： ENSO预报深度学习春季预报障碍多维时空预报因子

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