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EXPLICIT SIMULATION ON THE TRACK AND INTENSITY OF TROPICAL CYCLONE WINNIE (1997)

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Journal of Hydrodynamics 2006年第6期18卷 736-741页

作者： ZHONG Zhong ZHANG Jirl-shan institute of meteorology PLA University of Science and Technology Nanjing 211101 China nanjing Hydraulic Research institute Nanjing 210029 China

An explicit simulation of the tropical cyclone Winnie （1997） was conducted by use of a triply-nested 3-D nonhydrostatic mesoscale model MM5, before and after its landfall. The simulated results show that the model can well reproduce the track of Winnie （1997） with a BOGUS storm-like vortex inserted in the large-scale first-guess field at the initial model time. The mean track error in a 6 h interval is 54.5 km, which is much less than that obtained with the operational prediction. Comparisons between simulation and observation near the landfall place show that the main temporal variation features of sea level pressure and surface wind speed can also be successfully captured. The characteristics of the eyewall, the spiral cloud band and the corresponding precipitation were disclosed, and the applications of the model outputs were also discussed.

关键词： tropical cyclone simulation track intensity,eyewall spiral cloud band storm surge

A SEMI-CIRCLE THEOREM FOR UNSTABLE PERTURBATION IN TROPICAL CYCLONE-SCALE VORTICLES

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Journal of Hydrodynamics 2009年第4期21卷 473-481页

作者： HUANG Hong ZHANG Ming XU Ming institute of meteorology PLA University of Science and Technology Nanjing 211101 China Shanghai Typhoon institute China Meteorological Administration Shanghai 200030 China Laboratory of Typhoon Forecast Technique/CMA Shanghai 200030 China

In this paper, we discusses the spectrum distribution of baroclinic disturbances in tropical cyclone-scale vortices with the assumption that the basic flow does not vary with height. The semi-circle theorem for the unstable perturbation is obtained and the upper bound of growth rate can be estimated. The upper bound of instability growth rate increases with the increase of the maximum basic-state tangential wind speed, angular speed, inertial parameter, absolute vorticity, radial gradient of absolute vorticity and static stability. The upper bound of instability growth rate is greater for vortices of larger horizontal scale and smaller vertical scale and lower wave-number disturbances.

关键词： tropical cyclone-scale vortex spiral bands instability semi-circle theorem

NUMERICAL EXPERIMENTS ABOUT GROWTH OF THE ENERGY OF DISTURBANCE IN A BAROCLINIC FLOW

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Journal of Hydrodynamics 2008年第4期20卷 499-506页

作者： TENG Jia-jun HUANG Si-xun ZHANG Liang School of science PLA University of Science and Technology Nanjing 211101 China Shanghai institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200072 China institute of meteorology PLA University of Science and Technology Nanjing 211101 China

This article is concerned with the growth of energy of disturbances in a baroclinic flow within a finite time period. The implicit difference scheme was applied to the linearized vorticity equation, and the disturbance energy was computed for three kinds of vertical shears. It turns out that all the disturbance energy rapidly increases initially, and during the succeeding period there are several stages of growth and decay of energy of disturbances, and from a certain time on, all the disturbance energy begins to decrease.

关键词： implicit difference scheme vertical shear linearized potential vorticity equation disturbance energy Couette flow

ENVIRONMENTAL AND TOPOGRAPHIC INFLUENCES ON ATMOSPHERIC INTERNAL SHIP WAVES

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Journal of Hydrodynamics 2008年第4期20卷 440-447页

作者： ZANG Zeng-liang PAN Xiao-bin ZHANG Ming Department of Martial meteorology Institute of Meteorology PLA University of Science and TechnologyNanjing 211101 China State Key Laboratory of Atmospheric sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

A theoretical model was used to investigate the influences of environmental and topographic parameters on the atmospheric three-layer internal ship waves. The results show that both the wavelength and the wedge angle decrease with an increase in the Scorer parameter, and the rate of changes in the wavelength and wedge angle are also alike. The results also show that the wedge angle decreases with an increase in the width of mountain, but the wavelength varies little with it. It is suggested that the wedge angle is determined by the ratio of the wavelength to the scale of the mountain. Besides, numerical sensitivity experiments were performed to test the former numerical experiments. The simulated results are consistent with the analytical results.

关键词： Scorer parameter topographic parameter atmospheric internal ship waves numerical simulation

Computational properties of a new horizontal staggered grid

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science china Earth sciences 2005年第9期48卷 1559-1568页

作者： LIU YudiState Key Laboratory of Numerical Modeling for Atmospheric sciences and Geophysical Fluid Dynamics, institute of Atmospheric Physics, Chinese Academy of sciences, Beijing 100029, china institute of meteorology, pla university of science and technology, nanjing 211101, china State Key Laboratory of Numerical Modeling for Atmospheric sciences and Geophysical Fluid Dynamics Institute of Atmospheric Ph Chinese Academy of Sciences Beijing China institute of meteorology PLA University of Science and Technology Nanjing China

This paper presents a new horizontal staggered grid (LE grid), which defines h at a gridpoint, and both u and v at the same mid-gridpoint along the x and y directions. A general method is used to deduce the dispersion relationships of describing inertia gravity waves on LE grid and Arakawa A―E grids, which are then compared with the analytical solution (AS) in re- solved or under-resolved cases, using two-order central difference or four-order compact differ- ence scheme from the frequency and group velocity. Results show that in both resolved and under-resolved cases, no matter whether two-order central difference or four-order compact dif- ference scheme is used, the frequency and group velocity discrete errors on LE grid in describing inertia gravity waves are smaller than those of Arakawa A―E grids. At the same time, it is only on LE or Arakawa grid C that the employment of a compact difference scheme of higher difference precision can improve their accuracy in describing inertia gravity waves. However, as for the other four grids (Arakawa A,B,D and E), when the difference precision increases, the accuracy of simulating inertia gravity waves decreases.

关键词： horizontal staggered grid, inertia gravity wave, LE grid, Arakawa A-E grid, compact difference scheme, central difference.

THEORETICAL ANALYSES AND NUMERICAL EXPERIMENTS FOR TWO-DIMENSIONAL WIND RETRIEVALS FROM SINGLE-DOPPLER DATA

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Journal of Hydrodynamics 2010年第2期22卷 185-195页

作者： HUANG Si-xun CAO Xiao-qun DU Hua-dong ZHONG Ji-qin institute of meteorology PLA University of Science and Technology Nanjing 211101 China National university of Defense Technolog Changsha 410073 China institute of Urban meteorology China Meteorological Administration Beijing 100089 China

Based on variational adjoint methods,theoretical analyses and numerical experiments are performed for retrievals of two-dimensional winds and related parameters from single-Doppler radar data in polar *** the method,the reflectivity conservation equation is used as the governing equation and the mass continuity equation as a weak *** the same time,the stable functional of regularization and background field are also introduced in the cost *** on the ideal experiments with artificial data,real two-dimensional wind fields are retrieved with low-altitude data from the nanjing Doppler Radar Station,and the results are encouraging and promising.

关键词： single-Doppler retrievals adjoint methods regularization methods two-dimensional wind

NEW WAVE-DEPENDENT FORMULAE FOR SEA SPRAY FLUX AT AIR-SEA INTERFACE

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Journal of Hydrodynamics 2009年第4期21卷 573-581页

作者： SHI Jian ZHAO Dong-liang LI Xun-qiang ZHONG Zhong Key Laboratory of Coastal Disaster and Defense Ministry of Education Hohai University Nanjing 210098 China institute of meteorology PLA University of Science and Technology Nanjing 211101 China College of Physical and Environment Oceanography Ocean University of China Qingdao 266100 China

A bubble-derived Sea Spray Generation Function （SSGF） was deduced, which was integrated into the new wave-dependent SSGF. The effect of sea spray feedback was parameterized by the feedback coefficients A and B. The relationship of A（B） and the wind-sea Reynolds number was derived, which shows that the feedback effect of sea spray is decreasing with the wave developing. New sea spray flux formulae, including the new SSGF and new feedback coefficients, were proposed, which can reveal clearly the influence of wave state on sea spray fluxes. Spray fluxes in the Humidity Exchange Over the Sea （HEXOS） experiment were simulated again, and results show that spray momentum flux is small in this experiment, but spray heat flux is large. Comparisons of the sea spray fluxes calculated by two kinds of formulae in different wave states show that previous wave-independent spray flux formulae are the special cases of the presented new wave dependent formulae for sea spray flnx.

关键词： sea sray flux HEXOS wave state Sea Spray Generation Function (SSGF)

Covarying modes of the Pacific SST and northern hemispheric midlatitude atmospheric circulation anomalies during winter

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Progress in Natural science:Materials International 2008年第10期18卷 1261-1270页

作者： Yimin Zhu~(a,b,*) Xiuqun Yang~a Qian Xie~b Yongqiang Yu~c ~a Department of A tmospheric science,nanjing university,nanjing 210093,china ~b institute of meteorology,pla university of science and technology,nanjing 211101,china ~c LASG,institute of Atmospheric Physics,Chinese Academy of sciences,Beijing 100029,china Department of Atmospheric science Nanjing University Nanjing 210093 China institute of meteorology PLA University of Science and Technology Nanjing 211101 China LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

The interannual-to-interdecadal relationship between the Pacific sea surface temperature (SST) and the northern hemispheric midlati- tude’s atmosphere represented by the circumpolar vortex was documented with the global oceanic and atmospheric reanalysis data of recent 50 *** covarying modes of the Pacific SST and northern circumpolar vortex anomalies during winter were examined using the sin- gular value decomposition and wavelet analysis *** is the interannual,ENSO-related mode and the other is the interdecadal, North Pacific SST-related mode with a period of around 20 *** two modes exhibit distinct spatial *** the interannual mode,the SST anomaly is characterized by a typical ENSO pattern with the principal signature in the tropical eastern Pacific and secondary one in the central North Pacific,while the atmospheric anomaly is regional,characterized by a Pacific-North American *** the inter- decadal mode,large SST anomaly is located in the central North Pacific,while the atmospheric anomaly is zonally global,associated with the midlatitute’s standing long-wave *** the central North Pacific is colder,the long-wave is stronger,and vice *** investigations suggest that the interdecadal mode could involve an interaction between "two oceans and an atmosphere".

关键词： Sea surface temperature Atmospheric circulation ENSO Decadal variability

NUMERICAL SIMULATIONS OF SEA ICE WITH DIFFERENT ADVECTION SCHEMES

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Journal of Hydrodynamics 2011年第3期23卷 372-378页

作者： LIU Xi-ying State Key Laboratory of Numerical Modeling for Atmospheric sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China institute of meteorology PLA University of Science and Technology Nanjing 211101 China

Numerical simulations are carried out for sea ice with four different advection schemes to study their effects on the simulation results. The sea ice model employed here is the Sea Ice Simulator （SIS） of the Geophysical Fluid Dynamics Laboratory （GFDL） Modular Ocean Model version 4b （MOM4b） and the four advection schemes are, the upwind scheme originally used in the SIS, the Multi-Dimensional Positive Advection （MDPA） scheme, the Incremental Remapping Scheme （IRS） and the Two Step Shape Preserving （TSSP） scheme. The latter three schemes are newly introduced. To consider the interactions between sea ice and ocean, a mixed layer ocean model is introduced and coupled to the SIS. The coupled model uses a tri-polar coordinate with 120x65 grids, covering the whole earth globe, in the horizontal plane. Simulation results in the northern high latitudes are analyzed. In all simulations, the model reproduces the seasonal variation of sea ice in the northern high latitudes well. Compared with the results from the observation, the sea ice model produces some extra sea ice coverage in the Greenland Sea and Barents Sea in winter due to the exclusion of ocean current effects and the smaller simulated sea ice thickness in the Arctic basin. There are similar features among the results obtained with the introduced three advection schemes. The simulated sea ice thickness with the three newly introduced schemes are all smaller than that of the upwind scheme and the simulated sea ice velocities of movement are all smaller than that of the upwind scheme. There are more similarities shared in the results obtained with the MPDA and TSSP schemes.

关键词： advection scheme sea ice simulation