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Validation of the multi-satellite merged sea surface salinity in the South China Sea

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Journal of Oceanology and Limnology 2023年第6期41卷 2033-2044页

作者： Huipeng WANG Junqiang SONG Chengwu ZHAO Xiangrong YANG Hongze LENG Nan ZHOU College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410073China troop 61741 PLABeijing 100094China

Sea surface salinity(SSS)is an essential variable of ocean dynamics and climate research.The Soil Moisture and Ocean Salinity(SMOS),Aquarius,and Soil Moisture Active Passive(SMAP)satellite missions all provide SSS measurements.The European Space Agency(ESA)Climate Change Initiative Sea Surface Salinity(CCI-SSS)project merged these three satellite SSS data to produce CCI L4SSS products.We validated the accuracy of the four satellite products(CCI,SMOS,Aquarius,and SMAP)using in-situ gridded data and Argo floats in the South China Sea(SCS).Compared with in-situ gridded data,it shows that the CCI achieved the best performance(RMSD:0.365)on monthly time scales.The RMSD of SMOS,Aquarius,and SMAP(SMOS:0.389;Aquarius:0.409;SMAP:0.391)are close,and the SMOS takes a slight advantage in contrast with Aquarius and SMAP.Large discrepancies can be found near the coastline and in the shelf seas.Meanwhile,CCI with lower RMSD(0.295)perform better than single satellite data(SMOS:0.517;SMAP:0.297)on weekly time scales compared with Argo floats.Overall,the merged CCI have the smallest RMSD among the four satellite products in the SCS on both weekly time scales and monthly time scales,which illustrates the improved accuracy of merged CCI compared with the individual satellite data.

关键词： sea surface salinity(SSS) South China Sea(SCS) Argo multi-satellite merged data validation

Projection of China's Near- and Long-Term Climate in a New High-Resolution Daily Downscaled Dataset NEX-GDDP

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Journal of Meteorological Research 2017年第1期31卷 236-249页

作者： Yun BAO Xinyu WEN Department of Atmospheric and Oceanic Sciences School of Physics Peking University troop 61741 People's Liberation Army of China

The projection of China＇s near- and long-term future climate is revisited with a new-generation statistically down- scaled dataset, NEX-GDDP （NASA Earth Exchange Global Daily Downscaled Projections）. This dataset presents a high-resolution seamless climate projection from 1950 to 2100 by combining observations and GCM results, and re- markably improves CMIP5 hindcasts and projections from large scale to regional-to-local scales with an unchanged long-term trend. Three aspects are significantly improved：（1） the climatology in the past as compared against the ob- servations; （2） more reliable near- and long-term projections, with a modified range of absolute value and reduced inter-model spread as compared to CMIP5 GCMs; and （3） much added value at regional-to-local scales compared to GCM outputs. NEX-GDDP has great potential to become a widely-used high-resolution dataset and a benchmark of modem climate change for diverse earth science communities.

关键词： statistical downscaling climate projection climate change CMIP5 NEX-GDDP

Assimilation of temperature and salinity using isotropic and anisotropic recursive filters in Tropic Pacific

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Acta Oceanologica Sinica 2011年第1期30卷 15-23页

作者： LIU Ye ZHAO Yanling National Marine Environmental Forecasting Center Beijing 100081 China No 61741 Army troop Beijing 10081 China

A data assimilation scheme used in the updated Ocean three-dimensional Variational Assimila- tion System （OVALS）, OVALS2, is described. Based on a recursive filter （RF） to estimate the background error covariance （BEC） over a predetermined scale, this new analysis system can be implemented with anisotropic and isotropic BECs. Similarities and differences of these two BEC schemes are briefly discussed and their impacts on the model simulation are also investigated. An idealized experiment demonstrates the ability of the updated analysis system to construct different BECs. Furthermore, a set of three years experiments is implemented by assimilating expendable bathythermograph （XBT） and ARGO data into a Tropical Pacific circulation model. The TAO and WOA01 data are used to validate the assimilation results. The results show that the model simu- lations are substantially improved by OVALS2. The inter-comparison of isotropic and anisotropic BEC shows that the corresponding temperature and salinity produced by the anisotropic BEC are almost as good as those obtained by the isotropic one. Moreover, the result of anisotropic RF is slightly closer to WOA01 and TAO than that of isotropic RF in some special area （e.g. the cold tongue area in the Tropic Pacific）.

关键词： recursive filter anisotropic isotropic background error covariance

Development and application of automated vicarious calibration system

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Chinese Optics Letters 2017年第10期15卷 1-6页

作者：韦玮宋帅孙彦港邱刚刚李新郑小兵 Key Laboratory of Optical Calibration and Characterization Anhui Institute of Optics and Fine MechanicsChinese Academy of Sciences University of Sciences and Technology of China troop 61741 of PLA Shanghai Maritime University

In order to improve the frequency and precision of radiometric calibration, the automated vicarious calibration system（AVCS） is developed and deployed at the Dunhuang test site to perform vicarious calibration without the in situ manned measurements. The surface and atmospheric parameters are automatically collected by AVCS.An absolute radiometric calibration approach based on AVCS is proposed. Six successful calibrations of the Aqua Moderate Resolution Imaging Spectroradiometer（MODIS） are conducted. The results are in good agreement with the on-board calibration system with all the relative differences less than 4%. It enables us to monitor the change of a sensor over long time scales.

关键词： PSR Development and application of automated vicarious calibration system MODIS ATR

Evaluation of Ocean Data Assimilation in CAS-ESM-C:Constraining the SST Field

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Advances in Atmospheric Sciences 2016年第7期33卷 795-807页

作者： Xiao DONG Renping LIN Jiang ZHU Zeting LU International Center for Climate and Environment Sciences Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029 University of Chinese Academy of Sciences Beijing 100049 troop 61741 PLABeijing 100094

A weakly coupled assimilation system, in which SST observations are assimilated into a coupled climate model （CAS- ESM-C） through an ensemble optimal interpolation scheme, was established. This system is a useful tool for historical climate simulation, showing substantial advantages, including maintaining the atmospheric feedback, and keeping the oceanic tields from drifting far away from the observation, among others. During the coupled model integration, the bias of both surface and subsurface oceanic fields in the analysis can be reduced compared to unassimilated fields. Based on 30 model years of ot.tput fiom the system, the climatology and imerannual variability of the climate system were evaluated. The results showed that the system can reasonably reproduce the climatological global precipitation and SLP, bul it still sutters from the double ITCZ problem. Besides, the ENSO footprint, which is revealed by ENSO-related surface air temperature, geopotential height and precipitation during El Nifio evolution, is basically reproduced by the system. The system can also simulate the observed SST-rainfall relationships well on both interannual and intraseasonal timescales in the western North Pacific region, in which atmospheric feedback is crucial for climate simulation.

关键词： ocean data assimilation ensemble optimal interpolation CAS-ESM-C ENSO footprint atmospheric feedback,air-sea interaction western North Pacific

Cockroach-inspired Traversing Narrow Obstacles for a Sprawled Hexapod Robot

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Journal of Bionic Engineering 2022年第5期19卷 1288-1301页

作者： Xingguo Song Jiajun Pan Faming Lin Xiaolong Zhang Chunjun Chen Danshan Huang Mechanical Engineering School Southwest Jiaotong UniversityChengdu 610031China Unit 41 of troop 32272 Chinese People’s Liberation ArmyDeyang 618408China

Inspired by the cockroach’s use of a pitch-roll mode traverses through narrow obstacles,we improve the RHex-style robot by adding two sprawl joints to adjust the body posture,and propose a novel pitch-roll approach that enables an RHex-style robot to traverse through two cylindrical obstacles with a spacing of 90 mm,about 54%body width.First,the robot can pitch up against the obstacle on the one side by the cooperation of its rear and middle legs.Then,the robot rotates one side rear leg to kick the ground fast,meanwhile the sprawl joint on the other side rotates inward to make the robot roll and fall forward.Finally,the robot can rotate the legs on the ground to move the body forward until it crosses the obstacles.In this article,both cylinder and rectangular columns are considered as the narrow obstacles for traversing.The experiments are demonstrated by using the proposed approach,and the results show that the robot can smoothly traverse through different narrow spaces.

关键词： RHex-style robot Sprawl joint Pitch-roll mode Narrow obstacles

A Simulation Study on the Characteristics of Cloud Microphysics of Heavy Rainfall in the Meiyu Front

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Acta meteorologica Sinica 2009年第2期23卷 206-222页

作者：鞠永茂王汉杰钟中宋帅 Meteorological Center of 61741 troop PLA Key Laboratory of Regional Climate-Environment Research for Temperate East Asia Chinese Academy of Sciences Institute of Meteorology PLA University of Science and Technology

A heavy rainfall in the Meiyu front during 4-5 July 2003 is simulated by use of the non-hydrostatic mesoscale model MM5 （V3-6） with different explicit cloud microphysical parameterization schemes. The characteristics of microphysical process of convective cloud are studied by the model outputs. The simulation study reveals that：（1） The mesoscale model MM5 with explicit cloud microphysical process is capable of simulating the instant heavy rainfall in the Meiyu front, the rainfall simulation could be improved signifi- cantly as the model resolution is increased, and the Goddard scheme is better than the Reisner or Schultz scheme. （2） The convective cloud in the Meiyu front has a comprehensive structure composed of solid, liquid and vapor phases of water, the mass density of water vapor is the largest one in the cloud; the next one is graupel, while those of ice, snow, rain water and the cloud water are almost same. The height at which mass density peaks for different hydrometeors is almost unchangeable during the heavy rainfall period. The mass density variation of rain water, ice, and graupel are consistent with that of ground precipitation, while that of water vapor in the low levels is 1-2 h earlier than the precipitation. （3） The main contribution to the water vapor budget in the atmosphere is the convergence of vapor flux through advection and convection, which provides the main vapor source of the rainfall. Besides the basic process of the auto-conversion of cloud water to rain water, there is an additional cloud microphysical process that is essential to the formation of instant heavy rainfall, the ice-phase crystals are transformed into graupels first and then the increased graupels mix with cloud water and accelerates the conversion of cloud water to rain water. The positive feedback mechanism between latent heat release and convection is the main cause to maintain and develop the heavy precipitation.

关键词： MM5 Meiyu front torrential rain Goddard cloud microphysical process TRMM

Improving the energy release characteristics of PTFE/Al by doping magnesium hydride

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Defence Technology（防务技术） 2022年第2期18卷 219-228页

作者： Jia-xiang Wu Qiang Liu Bin Feng Qin Yin Yu-chun Li Shuang-zhang Wu Zhong-shen Yu Jun-yi Huang Xin-xin Ren College of Field Engineering Army Engineering University of PLANanjing210007China China Huayin Ordnance Test Center Huayin714200China 31104 troop of PLA Nanjing210001China

Magnesium hydride(MgH2)was doped into PTFE/Al to improve the energy release characteristics of the material system and strive for better application in military engineering.Five types of PTFE/Al/MgH2 reactive materials with different MgH2 content were prepared by molding sintering method.The dynamic mechanical properties of the materials were studied by performing split-Hopkinson pressure bar(SHPB)tests and scanning electron microscope characterizations.The thermal behavior,reaction energy,reaction process and reaction mechanism were systematically investigated by conducting thermogravimetry-differential scanning calorimetry tests,oxygen bomb calorimeter measurements,Xray diffraction and SHPB tests.The results show that MgH2 particles less than 10%content contribute to heightening the dynamic mechanical properties of PTFE/Al system.The product Mg generated by decomposition of MgH2 can not only react with gas phase C2F4þbut also undergo a Grignard-type reaction with condensed PTFE.The reaction energy and ignition threshold of PTFE/Al/MgH2 reactive materials enhance monotonously as MgH2 content rose.With the increase of MgH2 content from 0%to 20%,the reaction time is prolonged as well as the reaction intensity is enhanced dramatically arising from the massive water vapour produced by the reaction between O2 and H2.The gaseous products generated can form a high pressure shortly after the reaction,which helps to elevate the damage effect of the PTFE/Al system.

关键词： PTFE/Al/MgH_(2) Mechanical properties Thermal behavior Reaction energy Ignition threshold

A scheduling method based on a hybrid genetic particle swarm algorithm for multifunction phased array radar

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Frontiers of Information Technology & Electronic Engineering 2017年第11期18卷 1806-1816页

作者： Hao-wei ZHANG Jun-wei XIE Wen-long LU Chuan SHENG Bin-feng ZONG Air and Missile Defense College Air Force Engineering University Xi'an 710051 China troop 94225 Rizhao 276000 China troop 94710 Wuxi 214000 China

为解决多功能相控阵雷达的任务调度难题,本文提出了一种融合粒子群算法、遗传算法和启发式交错算法的优化算法。通过混沌理论优化粒子群算法的飞行参数,设计动态惯性权重,并引入遗传算法中的交叉、变异操作,使该算法的计算效率和寻优能... 详细信息

为解决多功能相控阵雷达的任务调度难题,本文提出了一种融合粒子群算法、遗传算法和启发式交错算法的优化算法。通过混沌理论优化粒子群算法的飞行参数,设计动态惯性权重,并引入遗传算法中的交叉、变异操作,使该算法的计算效率和寻优能力均得到大幅度提高。在智能算法的框架下,提出启发式的交错调度算法可进一步利用任务等待期的时间资源。仿真结果表明,与现有方法相比,本文算法效率更高,鲁棒性更强。

关键词：相控阵雷达调度粒子群算法遗传算法脉冲交错