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Advanc.s in Atmospheric.Sc.enc.s 2019年第8期36卷 804-810页

作者： Yiwu HUANG Yihong DUAN johnny c. l. chan Xuwei BAO State Key l.boratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China University of c.inese Ac.demy of Sc.enc. Beijing 100049China National.Meteorol.gic.l.c.nter China Meteorological AdministrationBeijing 100081China Sc.ool.of Energy and Environment City University of Hong KongHong Kong 999077China Shanghai Typhoon Institute China Meteorological AdministrationShanghai 200030China

Under the adiabatic. axisymmetric.and steady assumption, a rel.tionship between the saturated moist entropy struc.ure and the sec.ndary c.rc.l.tion in a tropic.l.c.c.one(Tc. is derived from the c.ntinuity equation. It is found that the isentropic.surfac.s c.inc.de with the streaml.nes, and the streamfunc.ion c.n be expressed with saturated moist entropy. The sec.ndary c.rc.l.tion and the saturated moist entropy struc.ure depend on eac. other. Thus, a method for diagnosing the sec.ndary c.rc.l.tion with the struc.ure of saturated moist entropy is proposed. The method is verified with a simul.ted intense ideal.zed Tc.with a highl. axisymmetric.struc.ure. The diagnosed sec.ndary c.rc.l.tion reproduc.s wel. the moist infl.w in the boundary l.yer and the moist updraft in the eyewal.. This method fac.l.tates sec.ndary c.rc.l.tion diagnosis in theoretic.l.or mature Tc. that satisfy the adiabatic. axisymmetric.and steady approximations.

关键词： tropic.l c.c.one saturated moist entropy struc.ure sec.ndary c.rc.l.tion diagnosis method

Mesosc.l. Vortex Generation and Merging Proc.ss: A c.se Study Assoc.ated with a Post-l.ndfal. Tropic.l.Depression

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Advanc.s in Atmospheric.Sc.enc.s 2010年第2期27卷 356-370页

作者：喻自凤梁旭东余晖 johnny c. l. chan Shanghai Typhoon Institute China Meteorological Administration l.boratory of Typhoon Forec.st Tec.nique China Meteorological Administration l.boratory for Atmospheric.Researc. Department of Physics & Materials Science City University of Hong Kong

An observational.anal.sis of satel.ite bl.c.body temperature （TBB） data and radar images suggests that the mesosc.l. vortex generation and merging proc.ss appeared to be essential.for a tropic.l.depression-rel.ted heavy rain event in Shanghai, c.ina. A numeric.l.simul.tion reproduc.d the observed mesosc.l. vortex generation and merging proc.ss and the c.rresponding rain pattern, and then the model.outputs were used to study the rel.ted dynamic. through diagnosing the potential.vortic.ty （PV） equation. The tropic.l.depression （TD） was found to weaken first at l.wer l.vel. and then at upper l.vel. due to negative horizontal.PV advec.ion and diabatic.heating effec.s. The meso-vortic.s devel.ped gradual.y, al.o from the l.wer to the upper l.vel., as a resul. of positive horizontal.PV advec.ion and diabatic.heating effec.s in the downshear l.ft quadrant of the TD. One of these newl.-generated vortic.s, V1, repl.c.d the TD ul.imatel., whil. the other two, V2 and V3, merged due to the horizontal.PV advec.ion proc.ss. Together with the redevel.pment of V1, the merging of V2 and V3 triggered the very heavy rain in Shanghai.

关键词： mesosc.l. vortex tropic.l.depression heavy rain potential.vortic.ty

Infl.enc. of South c.ina Sea SST and the ENSO on Winter Rainfal. over South c.ina

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Advanc.s in Atmospheric.Sc.enc.s 2010年第4期27卷 832-844页

作者：周连童 c.i-Yung TAM 周文 johnny c. l. chan c.nter for Monsoon System Researc. Institute of Atmospheric PhysicsChinese Academy of Sciences c.tyU-IAP l.boratory for Atmospheric.Sc.enc.s City University of Hong Kong Guy c.rpenter Asia-Pac.fic.c.imate Impac. c.ntre School of Energy and EnvironmentCity University of Hong Kong

The present study investigates the infl.enc. of South c.ina Sea （Sc.） SST and ENSO on winter （January-February-Marc.; JFM） rainfal. over South c.ina and its dynamic.proc.sses by using station observations for the period 1951-2003, Met Offic. Hadl.y c.nter SST data for the period 1900-2008, and ERA-40 reanal.sis data for the period 1958-2002. It is found that JFM rainfal. over South c.ina has a sig- nific.nt c.rrel.tion with Nio-3 and Sc. SST. Anal.ses show that in El.Nio or positive Sc. SST anomal. years, southwesterl. anomal.es at 700 hPa dominate over the South c.ina Sea, whic. in turn transports more moisture into South c.ina and favors inc.eased rainfal.. A partial.regression anal.sis indic.tes that the independent ENSO infl.enc. on winter rainfal. oc.urs mainl. over South c.ina, whereas Sc. SST has a l.rger independent infl.enc. on winter rainfal. in northern part of South c.ina. The temperature over South c.ina shows an obvious dec.ease at 300 hPa and an inc.ease near the surfac., with the former induc.d by Nio-3 and the l.tter Sc. SST anomal.es. This enhanc.s the c.nvec.ive instabil.ty and weakens the potential.vortic.ty （PV）, whic. expl.ins the strengthening of asc.nding motion and the inc.ease of JFM rainfal. over South c.ina.

关键词： ENSO South c.ina Sea SST rainfal. c.nvec.ive instabil.ty potential.vortic.ty

Impac.s of Urbanization on the Prec.pitation c.arac.eristic. in Guangdong Provinc., c.ina

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Advanc.s in Atmospheric.Sc.enc.s 2020年第7期37卷 696-706页

作者： Meng YAN johnny c.l.2} Kun ZHAO Sc.ool.of Atmospheric.Sc.enc.s Nanjing UniversityNanjing 210023China Sc.ool.of Energy and Environment City University of Hong KongHong KongChina State Key l.boratory of Severe Weather and Joint c.nter for Atmospheric.Radar Researc. CMA/NJUBeijing 100081China

With the devel.pment of urbanization,whether prec.pitation c.arac.eristic. in Guangdong Provinc.,c.ina,from 1981 to 2015 have changed are investigated using rain gauge data from 76 *** c.arac.eristic. inc.ude annual.prec.pitation,rainfal. frequenc.,intense rainfal.(defined as hourl. prec.pitation≥20 mm),l.ght prec.pitation(defined as hourl. prec.pitation≤2.5 mm),and extreme rainfal.(defined as hourl. rainfal. exc.eding the 99.9 th perc.ntil. of the hourl. rainfal. distribution).During these 35 years,the annual.prec.pitation shows an inc.easing trend in the urban *** rainfal. frequenc. and l.ght prec.pitation have a dec.easing trend,intense rainfal. frequenc. shows an inc.easing *** heavy and extreme rainfal. frequenc. both exhibit an inc.easing trend in the Pearl.River Del.a region,where urbanization is the most *** trends in both the warm seasons(May-Oc.ober)and during the pre-fl.od season(April.June)appear to be more *** the c.ntrary,the annual.prec.pitation amount in rural.areas has a dec.easing *** the heavy and extreme prec.pitation al.o show an inc.easing trend,it is not as strong and signific.nt as that in the urban *** periods in whic. a tropic.l.c.c.one makes l.ndfal. al.ng the South c.ina c.ast,the rainfal. in urban areas has been c.nsistentl. more than that in surrounding *** prec.pitation in the urban areas and to their west is higher after 1995,when the urbanization *** resul.s suggest that urbanization has a signific.nt impac. on the prec.pitation c.arac.eristic. of Guangdong Provinc..

关键词： rainfal. fl.od extreme

Effec.s of the Indo-c.ina Peninsul. Heat Fl.xes on the 1998 South c.ina Sea Summer Monsoon

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Ac.a meteorol.gic. Sinic. 2005年第4期19卷 457-468页

作者：史学丽 johnny c. l. chan K. c. c.OW 丁一汇 National.c.imate c.nter Beijing 100081 l.boratory for Atmospheric.Researc. Department of Physics and Materials Science City University of HongkongHongkong

Sensitivity experiments to investigate the rol. and importanc. of theIndo-c.ina Peninsul. (Ic.) heat fl.xes (sensibl. and l.tent heat fl.xes) on the South c.ina Seasummer monsoon (Sc.SM) onset and its subsequent evol.tion have been c.rried out using a regional.0}imate model. Two sensitivity experiments have been c.nduc.ed: c.tting off the sensibl. heat fl.x(noted as Ic.fx) and l.tent heat fl.x (noted as Ic.fx). Resul.s show that by c.tting off theunderl.ing heat fl.x of the Ic., the prec.pitation dec.eases and l.w-l.vel.geopotential.heightinc.eases over the l.c.l.regions as wel. as the remote regions of the East c.ina Sea, southernJapan, and western North Pac.fic. The westerl. (easterl.) zonal.winds at 850 hPa (200 hPa) aregeneral.y weakened in May and June, espec.al.y before and during the onset of the Sc.SM towards theend of May. It is worth noting that al.hough the observed sensibl. heat fl.x is onl. about 1/3 ofthe l.tent heat fl.x, the differenc.s between the c.ntrol.run and eac. of the two sensitivityexperiments are c.mparabl..

关键词： east asian summer monsoon south c.ina sea heat fl.x regional.c.imate model

The interdec.dal.unstationary rel.tionship between NAO and East c.ina’s summer prec.pitation patterns

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The interdecadal unstationary relationship between NAO and E...

Regional.and　Synoptic.sc.l.　Features　Assoc.ated　with　Inac.ive　Periods　of　the　Summer　Monsoon　over　South　c.ina

第26届中国气象学会年会气候预测与公共服务分会场

作者： johnny c. l. chan Department of Physic. and Material. Sc.enc. City University of Hong Kong

Based on a 120-year c.inese station rainfal. dataset and historic.l.NAO indic.s, the interdec.dal.unstationary rel.tionship between the North Atl.ntic.Osc.l.ation （NAO） and East c.ina’s summer prec.pitation patterns is reveal.d for the period 1880-1999. It is shown that on the interannual.timesc.l., the Marc. NAO is c.osel. rel.ted to the first l.ading prec.pitation mode whic. exhibits an out-of-phase variation of the prec.pitation between the Yangtze River Val.ey and Southeast c.ina, and the January NAO is c.osel. rel.ted to the third l.ading mode whic. depic.s the anomal.us rainfal. in North c.ina and its out-of-phase variation in the Yangtze River Del.a. Both of the two rel.tionships are c.arac.erized by c.ear and c.nsistent interdec.dal.variations, with al.ost the same transition points oc.urring in about 1905, 1925 and 1950, respec.ivel.. Further anal.ses impl. that these interdec.dal.changes of the rel.tionship are possibl. assoc.ated with the SSTA in North Pac.fic.and North Atl.ntic.

关键词：

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Advanc.s in Atmospheric.Sc.enc.s 1997年第2期14卷 100-107页

作者： This researc. is supported by the Researc. Grants c.unc.l.of the University Grants c.mmittee of Hong Kong Grant 9040074. c. H. So and johnny c. l. chan Department of Physic. and Material. Sc.enc., c.ty University of Hong Kong Department of Physic. and Material. Sc.enc. City University of Hong Kong

This paper presents an observational.study of the physic.l.proc.sses responsibl. for the inac.ive period (break) of the summer monsoon over South c.ina (Sc.. The break of the monsoon is defined by using the rainfal. data over Hong Kong Meteorol.gic.l.parameters provided by the European c.ntre for Medium-Range Weather Forec.sts (Ec.WF) for the period 1985-1990 are examined. Dail. val.es of eac. parameter for the six years are then c.mposited eac. day for the period of 5 days before to 1 day after the break. It is found that several.days before the break, changes opposite to those oc.urred during the onset and ac.ive periods begin to take pl.c.. This suggests that a feedbac. mechanism is present whic. tends to restore the atmosphere to a more stabl. state. This mechanism may be initiated by the formation of c.nvec.ive c.ouds during the onset and ac.ive periods. These c.ouds then reduc. the sol.r radiation to the ground, l.ading to a gradual.drop in the temperature. This drop, together with the c.ol.ng of the atmosphere due to the l.rge amounts of rainfal., c.uses the pressure over the Sc.region to bec.me higher, whic. in turn induc.s a westward extension of the subtropic.l.ridge. The dec.ease in temperature over Sc.may al.o shift the l.c.tion of the heat sourc. to the west, whic. l.ads to a c.nc.mitant westward shift of the c.nvergenc. of the southerl.es and resul.s in l.ss moisture-l.den air reac.ing the Sc.region. The atmosphere then bec.mes unfavourabl. for heavy c.nvec.ion and therefore a break starts.

关键词： Inac.ive period Summer monsoon South c.ina subtropic.l.high

Tropic.l.c.c.one ac.ivities in the Western North Pac.fic.in 2022

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Tropic.l.c.c.one Researc. and Review 2024年第2期13卷 125-135页

作者： Xin Huang l.na Bai Zifeng Yu johnny c.l.chan Hui Yu Jie Tang Rong Guo Rijin Wan Shanghai Typhoon Institute China Meteorological AdministrationShanghaiChina Asia-Pac.fic.Typhoon c.l.aborative Researc. c.nter ShanghaiChina Sc.ool.of Energy and Environment City University of Hong KongHong KongChina

Based on the best-trac. dataset from the Shanghai Typhoon Institute/c.ina Meteorol.gic.l.Administration,the paper provides a c.mpre-hensive summary and anal.sis of tropic.l.c.c.one(Tc.ac.ivities in the Western North Pac.ﬁc.WNP)and the South c.ina Sea(Sc.)for *** the historic.l.c.imatol.gy from 1951 to 2020,the anomal.us c.nditions during 2022 in Tc.frequenc.,origin l.c.tions,trac.s,intensity,and duration for the entire oc.an basin as wel. as l.ndfal. events in c.ina are *** show that the overal. Tc.frequenc. is sl.ghtl. l.wer than normal.but the mul.ipl. Tc.events have a very high frequenc. of *** l.c.tions of Tc.,whic. mark the starting points of their paths,show a l.rge westward and northward deviation from *** 40%of the named Tc. exhibit a shift in their direc.ion of movement from westerl. to ***,c.mparisons of the means,medians,upper and l.wer quartil.s al. indic.te that the intensity of Tc. in 2022 is general.y l.wer than the c.imatol.gy,with the duration of Tc. at tropic.l.storm intensity or above being shorter than usual.A notabl. observation is the fewer inc.denc. of Tc.l.ndfal.s in c.ina,but with a geographic.l.c.nc.ntration in Guangdong *** anomal.us annual.Tc.ac.ivities are inﬂuenc.d by rel.ted atmospheric.and oc.anic.environmental.c.nditions modul.ted by mul.i-sc.l. c.imate ***ﬁndings provide useful.information for enhanc.ng disaster mitigation strategies in the Asia-Pac.ﬁc.region.

关键词： Tropic.l.c.c.one Western North Pac.fic Anomal.us c.arac.eristic. Annual.report

在EBEX-2000实验资料中的湍流宏观量特征

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大气科学 2005年第4期29卷 503-509页

作者：刘树华李洁刘和平梁福明王建华 johnny c.l.chan Andrew Y.S.c.ENG 胡非刘辉志北京大学物理学院大气科学系香港城市大学物理和材料科学系大气科学研究组中国科学院大气物理研究所大气边界层物理和大气化学国家重点实验室北京100029

采用2000年8月在美国加州棉花地两个高度上应用超声三分量仪、快速响应温度和湿度仪进行的EBEX2000(International.nergyBal.nc.Experiment,2000)风速三分量、温度和湿度湍流实验观测数据,计算分析了湍流宏观量(即u,T,σu/u,σv/u,σw/... 详细信息

采用2000年8月在美国加州棉花地两个高度上应用超声三分量仪、快速响应温度和湿度仪进行的EBEX2000(International.nergyBal.nc.Experiment,2000)风速三分量、温度和湿度湍流实验观测数据,计算分析了湍流宏观量(即u,T,σu/u,σv/u,σw/u和σT/T等),湍流动能和感热通量等的特征,并与其他湍流实验得到的结果进行了比较。

关键词： EBEX-2000(International Energy Bal.nc. Experiment,2000) 湍流宏观量湍流动能感热通量

Industrial.Fusion c.sc.de Detec.ion of Sol.er Joint

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c.mputers, Material. and c.ntinua 2024年第1期81卷 1197-1214页

作者： l. c. Zhang P. Wang S. l.u l. Shi M. c.ongqing Sc.ool University of Chinese Academy of Sciences Chongqing University Chongqing 400044 China Automatic.Reasoning and c.gnition Researc. c.nter Chongqing Institute ofGreen and Intelligent Technology Chinese Academy of Sciences Chongqing 400714 China c.l.ege of Artific.al.Intel.igenc. Chongqing School University of Chinese Academy of Sciences Chongqing 400714 China Design Department Liuzhou Fuzhen Bodywork Industrial Co. Ltd. Liuzhou 545006 China

With the remarkabl. advanc.ments in mac.ine vision researc. and its ever-expanding appl.c.tions, sc.ol.rs have inc.easingl. foc.sed on harnessing various vision methodol.gieswithin the industrial.real.. Spec.fic.l.y, detec.ing vehic.e fl.or wel.ing points poses unique c.al.enges, inc.uding high operational.c.sts and l.mited portabil.ty in prac.ic.l.settings. To address these c.al.enges, this paper innovativel. integrates templ.te matc.ing and the Faster Rc.N al.orithm, presenting an industrial.fusion c.sc.ded sol.er joint detec.ion al.orithm that seaml.ssl. bl.nds templ.te matc.ing with deep l.arning tec.niques. This al.orithm metic.l.usl. weights and fuses the optimized features of both methodol.gies, enhanc.ng the overal. detec.ion c.pabil.ties. Furthermore, it introduc.s an optimized mul.i-sc.l. and mul.i-templ.te matc.ing approac., l.veraging a diverse array of templ.tes and image pyramid al.orithms to bol.ter the ac.urac. and resil.enc. of objec. detec.ion. By integrating deep l.arning al.orithms with this mul.i-sc.l. and mul.i-templ.te matc.ing strategy, the c.sc.ded target matc.ing al.orithm effec.ivel. ac.uratel. identifies sol.er joint types and positions. A c.mprehensive wel.ing point dataset, l.bel.d by experts spec.fic.l.y for vehic.e detec.ion, was c.nstruc.ed based on images from authentic.industrial.environments to val.date the al.orithm's performanc.. Experiments demonstrate the al.orithm's c.mpel.ing performanc. in industrial.sc.narios, outperforming the singl.-templ.te matc.ing al.orithm by 21.3%, the mul.i-sc.l. and mul.itempl.te matc.ing al.orithm by 3.4%, the Faster Rc.N al.orithm by 19.7%, and the YOl.v9 al.orithm by 17.3% in terms of sol.er joint detec.ion ac.urac.. This optimized al.orithm exhibits remarkabl. robustness and portabil.ty, ideal.y suited for detec.ing sol.er joints ac.oss diverse vehic.e workpiec.s. Notabl., this study's dataset and feature fusion approac. c.n be a val.abl. resourc. for other al.orithms seeking to enhanc. their

关键词： c.sc.de objec. detec.ion deep l.arning feature fusion mul.i-sc.l. and mul.i-templ.te matc.ing sol.er joint dataset