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Acta meteorologica Sinica 1995年第1期9卷 69-77页

作者：罗哲贤 Nanjing institute of meteorology Nanjing 210044

This paper generalizes the contour dynamics for single ring vortices to that for multiple ring vortices,wherein sixsets of numerical computation are *** phenomenon of the counterclockwise loop of a moving vortex is clearly shown in the computational results and the asymmetric change with time of the vortex structure may serve as a pre-cursor for the ***,we also discuss the dependence of the motion direction of a vortex upon the degreeof its contour denseness,and the dependence of the westward component of vortex motion upon its *** results are fairly consistent with those of previous dynamical analyses and numerical experiments.

关键词： contour dynamics multiple ring vortex Coriolis force nonlinearity

Comparative analysis of empirical and deep learning models for ionospheric sporadic E layer prediction

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Earth and Planetary Physics 2025年第1期9卷 10-19页

作者： BingKun Yu PengHao Tian XiangHui Xue Christopher JScott HaiLun Ye JianFei Wu Wen Yi TingDi Chen XianKang Dou institute of Deep Space Sciences Deep Space Exploration LaboratoryHefei 230088China CAS Key Laboratory of Geospace Environment School of Earth and Space SciencesUniversity of Science and Technology of ChinaHefei 230026China Hefei National Laboratory University of Science and Technology of ChinaHefei 230088China Department of meteorology University of ReadingReading RG66BBUK

Sporadic E(Es)layers in the ionosphere are characterized by intense plasma irregularities in the E region at altitudes of 90-130 *** they can significantly influence radio communications and navigation systems,accurate forecasting of Es layers is crucial for ensuring the precision and dependability of navigation satellite *** this study,we present Es predictions made by an empirical model and by a deep learning model,and analyze their differences comprehensively by comparing the model predictions to satellite RO measurements and ground-based ionosonde *** deep learning model exhibited significantly better performance,as indicated by its high coefficient of correlation(r=0.87)with RO observations and predictions,than did the empirical model(r=0.53).This study highlights the importance of integrating artificial intelligence technology into ionosphere modelling generally,and into predicting Es layer occurrences and characteristics,in particular.

关键词： ionospheric sporadic E layer radio occultation ionosondes numerical model deep learning model artificial intelligence

A STUDY ON THE PRECIPITATION CHARACTERISTICS OVER THE SOUTH CHINA SEA BEFORE AND AFTER THE MONSOON ONSET

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Journal of Tropical meteorology 2012年第1期18卷 1-10页

作者：李耀东宋明坤胡亮 institute of Aviation meteorology institute of meteorology PLA University of Science and Technology National Satellite meteorology Center CMA

This paper presents a study on the temporal and spatial variations of the precipitation over the area of the South China Sea (SCS) during the monsoon onset period. The data used are from the Tropical Rainfall Measuring Mission (TRMM) observations between April and June over the nine years from 1998 to 2006. This study focuses on the central and northern part of South China Sea (110-120°E, 10-20°N). Based on the observations, the 27th pentad is selected as the occurrence time of the SCS monsoon onset. The conclusions are as follows. (1) After the monsoon onset, the specific area, defined as the ratio of the number of pixels with certain type of precipitation to the number of total pixels, extends significantly for both convective and stratiform rain, with the latter having a larger magnitude. The specific rainfall, defined as the ratio of the amount of certain type of precipitation to the total amount of precipitation, decreases for convective rain and increases for stratiform rain. (2) Results also show significant increase in heavy rain and decrease in light rain after the monsoon onset. (3) Changes are also observed in the rainfall horizontal distributions over the SCS before and after the monsoon onset, manifested by the relocation of precipitation minima for both convective and stratiform rain. (4) After the monsoon onset, the variability in characteristics of precipitation vertical structure increases significantly, leading to more latent heat release and consequently deeper convection. Meanwhile, the bright-band altitude of stratiform precipitation is also elevated.

关键词： TRMM South China Sea monsoon onset precipitation

Variational assimilation in combination with a regularization method for sea level pressure retrieval from QuikSCAT scatterometer data Ⅱ:simulation experiment and actual case study

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Chinese Physics B 2011年第12期20卷 510-516页

作者：张亮黄思训沈春施伟来 institute of meteorology PLA University of Science and Technology

The sea level pressure field can be computed from sea surface winds retrieved from satellite microwave scatterometer measurements, based on variational assimilation in combination with a regularization method given in part I of this paper. First, the validity of the new method is proved with a simulation experiment. Then, a new processing procedure for the sea level pressure retrieval is built by combining the geostrophic wind, which is computed from the scatterometer 10-meter wind using the University of Washington planetary boundary layer model using this method. Finally, the feasibility of the method is proved using an actual case study.

关键词： scatterometer sea level pressure variational assimilation regularization QuikSCAT

Refractivity estimations from an angle-of-arrival spectrum

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Chinese Physics B 2011年第2期20卷 586-591页

作者：赵小峰黄思训 institute of meteorology PLA University of Science & Technology

This paper addresses the probability of atmospheric refractivity estimation by using field measurements at an array of radio receivers in terms of angle-of-arrival spectrum. Angle-of-arrival spectrum information is simulated by the ray optics model and refractivity is expressed in the presence of an ideal tri-linear profile. The estimation of the refractivity is organized as an optimization problem and a genetic Mgorithm is used to search for the optimal solution from various trial refractivity profiles. Theoretical analysis demonstrates the feasibility of this method to retrieve the refractivity parameters. Simulation results indicate that this approach has a fair anti-noise ability and its accuracy performance is mainly dependent on the antenna aperture size and its positions.

关键词： refractivity estimation angle-of-arrival spectrum ray optics model genetic algorithm

Ray tracing/correlation approach to estimation of surface-based duct parameters from radar clutter

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Chinese Physics B 2010年第4期19卷 484-491页

作者：赵小峰黄思训盛峥 institute of meteorology PLA University of Science and Technology

This paper describes a technique to estimate surface-based duct parameters by using a simple ray tracing/correlation method. The approach is novel in that it incorporates the Spearman rank-order correlation scheme between the observed surface clutter and the surface ray density for a given propagation path. The simulation results and the real data results both demonstrate the ability of this method to estimate surface-based duct parameters. Compared with the results obtained by a modified genetic algorithm combined with the parabolic wave equation, the results retrieved from the ray tracing/correlation scheme show a minor reduction in accuracy but a great improvement on computation time. Therefore the ray tracing/correlation method might be used as a precursor to more sophisticated and slower techniques, such as genetic algorithm and particle filters, by narrowing the parameter search space and providing a comprehensive and more efficient estimation algorithm.

关键词： ray tracing Spearman rank correlation surface-based duct radar clutter

Study on Moist Potential Vorticity and Symmetric Instabilityduring a Heavy Rain Event Occurred inthe Jiang-Huai Valleys

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Advances in Atmospheric Sciences 1999年第2期16卷 314-321页

作者：寿绍文李耀辉 Nanjing institute of meteorology Nanjing

In the light of the theory on moist potential vorticity (MPV) investigation was undertaken of the 700 hPa vertical (horizontal) component MP1 (MPV2) for the heavy rain event occurring in July 5–6, 1991. Results show that the distribution features of the two components were closely related to the development of a mesoscale cyclone as a rainstorm-causing weather system in the lower troposphere in such a way that the ambient atmosphere of which MPV1 > 0 and MPV2 < 0 with |MPV1| ≥ |MPV2| favored the genesis of conditional symmetric instability (CSI) and that, as indicated by calculations, a CSI sector was really existent in the lower troposphere during the heavy rain happening and contributed greatly to its development.

关键词： Heavy rain Moist potential vorticity (MPV) Conditional symmetric instability

Conversion Characteristics between Barotropic and Baroclinic Circulations of the SAH in Its Seasonal Evolution

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Advances in Atmospheric Sciences 2000年第1期17卷 129-139页

作者：刘宣飞朱乾根郭品文 Nanjing institute of meteorology Nanjing

In the context of 1958–1997 NCEP/ NCAR re-analyses, the South Asia high (SAH) was divided into two components, barotropic and baroclinic, the former based on mass weighed vertical integration and the latter on the difference between the measured circulation and the barotropic component counterpart, whereupon the barotropic and baroclinic circulation conversion features were addressed of the research SAH during its seasonal variation. Evidence suggests that i) in summer (winter), the SAH is a thermal (dynamical) system, with dominant baroclinicity (barotropicity), either of the components accounting for approximately 70% of the total contribution; ii) as time progresses from winter to summer, accompanied by the barotropic SAH evolving into its baroclinic analog, the SAH is moving under the “ thermal guidance” of its baroclinic component circulation, suggesting that the component circulation precedes the system itself in variation; iii) the reversal happens when it goes from summer to winter, with the SAH displacement under the “ dynamic steering” of its barotropic component circulation. Key words SAH (South Asia high) - Barotropic circulation - Baroclinic circulation - Seasonal variation (1)This work is supported by the National Natural Sciences Foundation of China under Grant No.49735170.

关键词： SAH (South Asia high) Barotropic circulation Baroclinic circulation Seasonal variation

Influence of ENSO Event on the Maintenance of Pacific Storm Track in the Northern Winter

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Advances in Atmospheric Sciences 1999年第4期16卷 630-640页

作者：朱伟军孙照渤 Nanjing institute of meteorology Nanjing

An influence of ENSO event on the maintenance of Pacific storm track in the Northern winter is studied based on the NCEP/ NCAR daily re-analysis data. The result shows that in El Ni?o (La Ni?a) year an increase (decrease) of baroclinicity over the storm track, extension (withdrawal) eastward and southward (westward but northward for its east end) of its position and augmentation (debilitation) of its strength are closely in response to the enhancement (abatement) of eddy heat flux and momentum flux that are associated with the development of the storm track. It thus indicates that ENSO event exerts an important impact on its maintenance and development in the Pacific Ocean.

关键词： ENSO Storm track Baroclinicity

Remote sensing of atmospheric duct parameters using simulated annealing

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Chinese Physics B 2011年第9期20卷 468-475页

作者：赵小峰黄思训项杰施伟来 institute of meteorology PLA University of Science and Technology

Simulated annealing is one of the robust optimization schemes. Simulated annealing mimics the annealing process of the slow cooling of a heated metal to reach a stable minimum energy state. In this paper, we adopt simulated annealing to study the problem of the remote sensing of atmospheric duct parameters for two different geometries of propagation measurement. One is from a single emitter to an array of radio receivers （vertical measurements）, and the other is from the radar clutter returns （horizontal measurements）. Basic principles of simulated annealing and its applications to refractivity estimation are introduced. The performance of this method is validated using numerical experiments and field measurements collected at the East China Sea. The retrieved results demonstrate the feasibility of simulated annealing for near real-time atmospheric refractivity estimation. For comparison, the retrievals of the genetic algorithm are also presented. The comparisons indicate that the convergence speed of simulated annealing is faster than that of the genetic algorithm, while the anti-noise ability of the genetic algorithm is better than that of simulated annealing.

关键词： remote sensing refractivity estimation electromagnetic wave propagation simulatedannealing