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Analysis of Three Supercell Storms with Doppler Weather Radar Data

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Acta meteorologica Sinica 2011年第2期25卷 211-223页

作者：刁秀广朱君鉴刘志红 Shandong Weather forecast Office

Three supercell storms on 24 June 2004（0624）,28 June 2003（0628）,and 27 September 2002（0927） induced different damages in Shandong *** 0927 was inferior in size and intensity to storms 0628 and *** structure and evolvement of the three storms were analyzed in detail based on the WSR98D radar data in combination with weather *** results show that mesoscale surface convergence triggered release of instable energy,which resulted in severe *** the development stage,storms 0927,0628,and 0624 displayed multi-cell propagation,single-cell evolution,and multi-cell mergence,*** storm tracks were similar：they were all right-moving supercell storms,i.e.,moving at an angle of 30°-70° to the right of the mean wind and at a speed of about 45%-70% of the mean wind *** the mature stage,the maximum reflectivity appeared at the low level in storm 0927,mid level in storm 0628,and mid-upper level in storm *** storms possessed almost all typical features of supercell storms：weak echo region（WER）,bounded weak echo region（BWER）,and *** organized mesocyclone formed at the middle height of an updraft,deepened gradually downward and upward,and became a typical mid-level mesocyclone with strong *** vertical structures of airflows in the three storms were similar,i.e.,significant convergence at low level,nearly pure rotation at mid level,and divergent rotation at upper ***,signatures of mid-level horizontal airflows in the three storms were different：at mid level,there was a single vortex in storm 0628,but a double-vortex flow pattern was seen in storms 0927 and *** horizontal structure of the double-vortex flow was hard to be blown away by the environmental airflow,and thus the storms could persist for a longer period of time than the single vortex storm.

关键词： supercell storm mesocyclones inner structure double-vortex flow pattern

A Numerical Investigation of the Eyewall Evolution of a Tropical Cyclone

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Acta meteorologica Sinica 2009年第5期23卷 517-538页

作者：李青青端义宏傅刚余晖 Laboratory of Typhoon forecast Technique Shanghai Typhoon Institute of CMA National Meteorological Center department of Marine Meteorology Ocean University of China

In this study, a high-resolution numerical simulation is conducted to investigate the eyewall evolution of Typhoon Imbudo （2003）. The eyewall contraction, breakdown, and reformation are successfully simulated by the model. The eyewall accordantly shrinks throughout the whole troposphere prior to landfall, while it exhibits different variations after landfall in the lower and upper troposphere, respectively. It is found that the dry air advected into the storm inner core through a low-θe channel, the reduced surface latent heat transfer, and the increased inflows in the coastal region are associated with the eyewM1 contraction. Accompanied with the high-to-low wavenumber change in the vortex Rossby waves, the initial polygonal eyewall transforms to an elliptical one. Such a wavenumber change is likely associated with the change of interaction between the rainbands and the eyewall. The corresponding features of the time-averaged and vertical dynamic and thermodynamic structures are also examined during the storm passage. A tangential wind budget analysis indicates that a strong acceleration due to the contributions of both the eddy and the mean circulation is located in the lower layer in the eyewall during pre-landfall, and the mean circulation contribution to the change in the tendency of the azimuthally averaged tangential wind counteracts the eddy contribution.

关键词： Typhoon hnbudo eyewall contraction breakdown and reorganization dynamic and thermodynamic structures tangential wind budget

A user perspective on future cloud-based services for Big Earth data

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International Journal of Digital Earth 2021年第12期14卷 1758-1774页

作者： Julia Wagemann Stephan Siemen Bernhard Seeger Jörg Bendix Laboratory of Climatology and Remote Sensing(LCRS) Faculty of GeographyUniversity of Marburg forecast department European Centre for Medium-Range Weather Forecasts(ECMWF) department of Mathematics and Computer Science University of Marburg

Cloud-based services introduce a paradigm shift in how users access,process and analyse Big Earth data.A key challenge is to align the current state of how users access,process and analyse the data with trends and roadmaps large data organisations *** addition,due to the increased availability of open data,a more diverse user base wants to take advantage of Earth science data leading to new user *** run a web-based survey among Big Earth data users to better understand the motivation to migrate to cloud-based services as well as the challenges and opportunities that might *** show an overall interest in moving to cloud-based services but air an insufficient literacy in cloud systems and a lack of trust due to security concerns and opacity of emerging *** gaps demand efforts on three ***,cloud services shall be targeted at intermediate users instead of policy-and decision-makers and over-engineered systems with a high level of abstraction should be ***,more substantial capacity-building efforts are required to decrease the existing gap in cloud skills and ***,a cloud certification mechanism could help in building up overall trust in cloud-based services.

关键词： User requirements cloudbased services Big Earth data open data

Analysis of transient temperature field in coke drums

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Applied Mathematics and Mechanics(English Edition) 2010年第3期31卷 291-304页

作者：宁志华刘人怀 Key Laboratory of Disaster forecast and Control in Engineering Ministry of Education of ChinaJinan University Institute of Applied Mechanics and department of Mechanics and Civil Engineering Jinan University

One of the primary reasons leading to bulging and cracking in a coke drum is the severe temperature gradient due to cyclic temperature variation. Based on the twodimensional heat conduction theory, an analytical solution of the transient temperature field in the coke drum is obtained, which is different from the known FEM results. The length of the coke drum is considered finite. The dynamic boundary conditions caused by fluid uninterrupted rising in oiling and watering stages are simulated with the iteration method. Numerical results show that the present theoretical model can accurately describe basic features of the transient temperature field in the coke drum. Effects of the geometry of the coke drum and the rising velocity of quench water on the axial temperature gradient are also discussed.

关键词： coke drum cylindrical shell transient temperature field temperature gradient

Genesis of the Zhaokalong Fe-Cu Polymetallic Deposit at Yushu, China: Evidence from Ore Geochemistry and Fluid Inclusions

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Acta Geologica Sinica(English Edition) 2013年第2期87卷 486-500页

作者： LI Huan XI Xiaoshuang WU Chengming Koichiro WATANABE department of Earth Resources Engineering Faculty of Engineering Kyushu University MOE Key Laboratory of Non-ferrous Metal Ore Forecast School of Geosciences and Info-physics Central South University

The ore types of the Zhaokalong Fe-Cu deposit are divided into two categories： sulfide-type and oxide-type. The sulfide-type ore include siderite ore, galena-sphalerite ore and chalcopyrite ore, whereas the oxide-type ore include magnetite ore and hematite ore. The ore textures and structures indicate that the Zhaokalong deposit is of the sedimentary-exhalative mineralization type. Geochemical analyses show that the two ore types have a high As, Sb, Mn, Co and Ni content. The REE patterns reveal an enrichment of the LREE compared to the HREE. Isotopic analysis of siderite ore reveal that the j13CpDB ranges from -2.01 to 3.34 （%0） whereas the JISOsMow ranges from 6.96 to 18.95 （%0）. The fluid inclusion microthermometry results indicate that homogenization temperatures of fluid inclusions in quartz range from 131 to 181~C, with salinity values of 1.06 to 8.04 wt% NaCI eq. The mineralizing fluid therefore belongs to the low temperature - low salinity system, with a mineralizing solution of a CO2-Ca2＋（Na＋, K＋）-SO42- （F-, CI--H20 system. The geochemical results and fluid inclusion data provide additional evidence that the Zhaokalong deposit is a sedex-type deposit that experienced two stages of mineralization. The sulfide mineralization probably occurred first, during the sedimentary exhalative process, as exhibited by the abundance of marine materials associated with the sulfide ores, indicating a higher temperature and relatively deoxidized oceanic depositional environment. After the main exhalative stage, hydrothermal activity was superimposed to the sulfide mineralization. The later stage oxide mineralization occurred in a low temperature and relatively oxidized environment, in which magmatic fluid circulation was dominant.

关键词： exhalative sedimentary deposit (SEDEX) fluid inclusions ore geochemistry Zhaokalong,Sanjiang ore belt

Impacts of TRMM SRR assimilation on the numerical prediction of tropical cyclone

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Acta Oceanologica Sinica 2006年第5期25卷 14-26页

作者： MA Leiming QIN Zenghao DUAN Yihong LIANG Xudong WANG Dongliang Laboratory of Typhoon forecast Technique/China Meteorological Administration Shanghai Typhoon Institute Shanghai200030 China department of Atmospheric Sciences Nanjing University Nanjing 210093 China

Impacts of the four-dimensional variation （4DVAR） assimilation of Tropical Rainfall Measuring Mission （TRMM）/TMI surface rainfall rate （SRR） on the initialization and simulation of TC Danas in 2001 are studied. A number of sensitivity experiments are designed to evaluate the performance of assimilation during the particular stage when Danas developed from a tropical depression towards a typhoon, as well as an abrupt turning. Under the dynamic and thermodynamic constraints of meso-scale model and the 4DVAR, the TRMM SRR data are directly assimilated in high horizontal resolution （ 18 kin）. On the basis of the adjustment of initial model field, 4DVAR of TRMM SRR considerably improved the depiction of TC＇ s structure and rainfall. The same explanation can also be given to the enhancement of simulation on TC＇ s intensity and track. In comparison with the popular idea of twice steps of SRR assimilation, namely, 4DVAR pins 1DVAR, the retrieval error is expected to be avoided in the procedure of direct 4DVAR. In addition, the TRMM SRR 4DVAR within a high-resolution model can take into account as much information as observed and is expected to be performed in operational use if the observed rainfall data are routinely available.

关键词： TRMM TC Danas 4DVAR rainfall numerical simulation

NUMERICAL SIMULATION OF FRONTOGENESIS FORCED BY DUST RADIATIVE HEATING

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Acta meteorologica Sinica 1994年第2期8卷 136-149页

作者：申绍华陈受钧 National Research Center for Marine Environment forecast Beijing 100081 Department of GeophysicsPeking UniversityBeijing 100871

In this paper,the frontogenesis forced by dust radiative heating and the radiative effects of an isolated duststorrn on a frontal circulation system are examined by means of two-and three-dimensional numerical *** indicate that as a duststorm breaks out, frontogenesis is caused in by dust radiative heating in the lower atmosphere.A marked isentropic potential temperature layer is formed in the middle *** low-level convergence occurs along the direction of the front ***,dust radiative cooling results in frontolysis in the lower atmosphere. An obvious vertical circulation is forced by radiative heating of an isolated duststorm along the direction of the pre- vailing *** is stronger at day,weaker and reverse at *** response of the horizontal wind field to dust radiative forcing is different at different levels.

关键词： duststorm radiation frontogenesis numerical simulation

An improved modeling of precipitation phase and snow in the Lancang River Basin in Southwest China

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Science China(Technological Sciences) 2021年第7期64卷 1513-1527页

作者： HAN ZhongYing LONG Di HAN PengFei HUANG Qi DU MingDa HOU AiZhong State Key Laboratory of Hydroscience and Engineering Department of Hydraulic EngineeringTsinghua UniversityBeijing100084China Hydrological forecast Center Ministry of Water Resources of the People’s Republic of ChinaBeijing100053China

Precipitation phase(e.g., rainfall and snowfall) and snow(e.g., snowpack and snowmelt runoff) in high-mountain regions may largely affect runoff generation, which is critical to water supply, hydropower generation, agricultural irrigation, and ecosystems downstream. Accurately modeling precipitation phase and snow is therefore fundamental to developing a better understanding of hydrological processes for high-mountain regions and their lower reaches. The Lancang River(LR, or the Upper Mekong River)in China, among the most important transboundary rivers originating from the Tibetan Plateau, features active dam construction and complex water resources allocation of various stakeholders in Southeast Asian countries under climate change. This study aims to improve precipitation phase and snow modeling for the LR basin with a hydrological model and multisource remotely sensed data. Results show that joint use of the Moderate Resolution Imaging Spectroradiometer(MODIS) land surface temperature product with high spatial resolution(1 km×1 km) and an air temperature product can more precisely distinguish precipitation phase than air and wet-bulb temperature products in the LR basin. Snowfall and snowmelt were found to be controlled primarily by rainfall and snowfall temperature thresholds in snow modeling. The rainfall and snowfall temperature thresholds derived from the hydrological model through calibration with remotely sensed snowpack at basin scales were considerably lower than those derived from in situ observations. Rainfall and snowfall temperature thresholds derived from in situ observations could lead to the overestimation of snowmelt runoff due mostly to the lack of representation of point-based measurements at basin scales. This study serves as a basis for better modeling and predicting snow for the LR basin and potentially other similar basins globally.

关键词： distributed hydrological model snowfall snow water equivalent snowmelt Lancang River Basin

Mathematical modelling of axonal microtubule bundles under dynamic torsion

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Applied Mathematics and Mechanics(English Edition) 2018年第6期39卷 829-844页

作者： J.Y.WU Hong YUAN L.Y.LI MOE Key Laboratory of Disaster forecast and Control in Engineering Institute of Applied MechanicsJinan University School of Engineering University of Plymouth

Owing to its viscoelastic nature, axon exhibits a stress rate-dependent me- chanical behavior. An extended tension-shear chain model with Kelvin-Voigt viscoelas- ticity is developed to illustrate the micromechanical behavior of the axon under dynamic torsional conditions. Theoretical closed-form expressions are derived to predict the de- formation, stress transfer, and failure mechanism between microtubule （MT） and tau protein while the axon is sheared dynamically. The results obtained from the present an- alytical solutions demonstrate how the MT-tau interface length, spacing between the tau proteins, and loading rate affect the mechanical properties of axon. Moreover, it is found that the MTs are more prone to rupture due to the contributions from the viscoelastic effects. Under the torsional force, the MTs are so long that the stress concentrates at the loaded end where axonal MTs will break. This MT-tau protein dynamics model can help to understand the underlying pathology and molecular mechanisms of axonal injury. Additionally, the emphasis of this paper is on the micromechanical behavior of axon, whereas this theoretical model can be equally applicable to other soft or hard tissues, owning the similar fibrous structure.

关键词： torsion biocomposite diffuse axonal injury (DAI) Kelvin-Voigt viscoelas-tic model dynamic response tension-shear chain model