一次华南沿海海雾过程的观测分析与数值模拟研究
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摘要
本文针对发生在2007年3月24~25日的一次华南沿海海雾过程,利用1°×1°的间隔6小时一次的NCEP/NCAR实时再分析资料和地面观测、边界层探测、雾滴谱观测资料,分析了此次海雾的大尺度天气背景特征、贴地层气象要素的变化特征、边界层结构特征及微物理结构特征,并利用WRF模式模拟分析了此次海雾过程海面水温的变化特征及辐射对平流冷却雾过程的影响。通过研究,得出以下主要结论。
     (1)此次海雾过程发生在西南低涡发展的天气背景下,持续的偏南暖湿气流的输送,为海雾的生成和发展提供了有利条件。海雾过程中相对湿度与能见度有良好的负相关关系。
     (2)在西南低压控制下,海雾发展阶段的边界层大气呈现弱静力稳定状态。海雾可以在弱静力稳定度条件下发展和成熟,而不以逆温或强稳定层结为必要条件,凝结冷却形成的雾顶结构与典型的雾顶结构有显著差异,凝结冷却层有明显的超绝热现象。
     (3)在海雾发展阶段,边界层低层有明显的夜间低空急流现象。低空急流一方面起到抑制下层雾垂直发展,使雾顶变得模糊的作用;另一方面还有可能通过动力强迫混合方式使上层空气冷却,为雾层向上发展提供有利条件。
     (4)充分混合的海雾出现在几乎整个边界层水汽达到饱和并出现雾顶水汽凝结、长波辐射冷却增强的条件下;充分混合的雾层厚度可达600m左右。
     (5)当雾顶以上风切变增强、气温上升时,可能引发雾顶上干、暖空气卷夹进入雾层,导致雾层破碎或消散;当雾顶以上风切变减弱、气温下降时,辐射冷却也可能使雾层恢复。
     (6)深厚的雾层能降低太阳短波辐射对雾的消散作用。太阳辐射一方面会使上层空气增温、雾滴蒸发,但增温也有助于低层空气保持稳定,使地面的雾层继续维持,直到太阳辐射增温由上至下逐渐侵蚀雾层。
     (7)在雾的发展阶段和充分混合阶段雾滴的数浓度和含水量变化不大。雾顶卷夹导致雾滴的数浓度变化不大,但大雾滴的数量明显减少,含水量大幅降低。海雾滴谱具有局地特征,此次华南沿海海雾的微物理参量值均低于其它地区。
     (8)用WRF模式模拟的此次华南沿海海雾过程的海水表面温度低于24℃;在海雾的发展阶段以及充分混合阶段,气水温差在2℃以内。
     (9)通过WRF模式进行去除辐射项的敏感性试验,发现日间太阳短波辐射对海雾的消散过程有很大的影响,而夜间长波辐射则影响雾层的垂直发展。
The large scale synoptic background, near ground layer weather element, boundary layer structure and microphysical characteristics of a sustained sea fog event that occurred in the north part of the South China Sea on 24~25,march,2007,are analyzed by using the field observation and NCEP re-analysis data, and have a numerical study by the Weather Research Forecast Model (WRF) in the end. The following text is the main conclusions.
     (1) This sustained sea fog event is accompanied by southwest vortex developing southerly, and warm wet air flow continuously transport into the South China Sea both of them have advantage for the forming and developing of the sea fog. There is a good negative correlativity with relative humidity and visibility.
     (2) With control of southwest vortex, the aerosphere boundary layer has a feebleness static stabilization. The sea fog can develop and maturate in feebleness static stabilization, temperature inversion and strong stable stratification is not the sine qua non. There is notable difference between fog horizon forming by condensation cooling and typical fog horizon, and there is superadiabatic in condensation cooling layer.
     (3) In the developing phase, there is a obvious night lower tropospheric jet in the lower boundary layer. In one part, the lower tropospheric jet can choke back lower fog developing vertically, then fog horizon become illegible , and in another part, the higher aerosphere may cooling through dynamic forcing mixing, that is advantage for fog developing vertically.
     (4) The fully mixing fog occur in the condition of when boundary layer vapor is saturated, the fog horizon vapor condensation and long-wave radiation cooling enhanced. The fully mixing fog layer can reach the height of 600 m.
     (5) As there is not a strong temperature inversion layer, the fog horizon structure is different between forming form condensation and the typical one. The dry and wet air may enter into fog layer, when wind shear above fog horizon become stronger and air temperature rising, but radiation cooling also can renew fog layer.
     (6) The profound fog layer can reduce the dissipation effect from solar short-wave radiation. For one part, solar radiation can enhance higher aerosphere temperature and fog-drop vaporize, but air temperature increasing is also in favor of the lower air stabilization, and ground fog layer continue maintaining, until sea fog layer being gnawed from high layer to low layer by solar radiation.
     (7) In the developing and fully mixing phase, the number density and water content of fog-drop have an inconspicuous change, but the number of big fog-drop and water content reduce obviously, The sea fog-drops represent local features, the microphysical structure of the South China Sea is lower than other areas.
     (8) The sea surface temperature is under 24℃along the sea fog event, and air water temperature range is between 2℃in the developing and maturating phase.
     (9) Thought wiping off radiation calculate, we find that day short wave radiation have strong effect on fog dissipation and night long wave radiation have effect on fog layer developing vertically.
引文
[1]Roach,W.T.Back to basics:Fog:Part 1-Definitions and basic physics[J].Weather.1994,49.411-415.
    [2]Roach,W.T.Back to basics:Fog:Part 3-The formation and dissipation of sea fog[J].Weather.1995,50.80-84.
    [3]王彬华,海雾[M],北京,海洋出版社,1983。
    [4]Findlater,J.,W.Roach,and McHugh.B.The haar of north-east Scotland[J].Quart.J.Roy.Meteor.Soc.1989,115.581-608.
    [5]Filonczuk,M.K.,Cayan,D.R.,and Riddle,L.G..Variability of marine fog along the California coast[J].SIO Reference.1996,No,95-2.102.
    [6]Lewis J.M.,Koracin D.and Redmond K.T.Sea fog reaserch in the United Kingdom and United States:a historical essay including outlook[J],Bull.Amer.Meteor.Soc.2004,75.395-408.
    [7]Taylor,G.Eddy motion in the atmosphere[J].Philos.Trans.Roy.Soc.London Ser.A,1915,215,1-26.
    [8]Taylor,G.,The formation of fog and mis[J]t.Quart.J.Roy.Meteor.Soc.,1917,43,241-268.
    [9]Emmons,G.and Montgomery.R,Note on the physics of fog formation[J].J.Meteor.1947,Vol.4,206-212
    [10]Byers,H.Summer sea fogs of the central California coast[J].Publ.Geogr.1930,Vol.3,291-338.
    [11]Petterssen,S.On the causes and the forecasting of the California fog[J].Bull.Amer.Meteor.Soc.1938,19.49-55.
    [12]Fleagle,R G.A theory of fog formation[J].Marine Res,1953,Vol.12:43-50.
    [13]Douglas,C,Cold fogs over the sea[J].Meteor.Mag.1930,65,133-135.
    [14]Lamb,H.Haars or North Sea fogs on the coasts of Great Britain[J].Meteorology Office Publication M.O.1943,504,24 pp.
    [15]Rodhe,B.The effect of turbulence on fog formation[J].Tellus,1962,14:49-86.
    [16]Mack,E.,Katz,U.,Rogers.C.,and Pilie,C.,The microstructure of California coastal stratus and fog at sea[J].Calspan Corp.,Rep.1974,CJ-5405-M-1,74 pp
    [17]Pilie,R.,Mack,.E,Rogers,.C,ea tl.,The formation of marine fog and the development of fog-stratus systems along the California coast[J].Appl.Meteor.,1979:,18,1275-1286.
    [18]Findlater et al.Porject Haar.Air Clues[J].The magazine of Royal Air Force.1985,39(9).350-353.
    [19]Rogers D.P.and D.Koracin,Radiative transfer and turbulence in the cloud-topped marine atmospheric boundary layer[J].Atmos.Sci.,1992,49,1473-1486.
    [20]Koracin,D.J.and Lewis,W et al.Transition of stratus into fog along the California Coast:Observations and modeling[J].Atmos.Sci.2001,58.1714-1731
    [21]Nicholls,S.The dynamics of stratocumulus:Aircraft observation and comparison with a mixed layer mode[J]l.Quart.J.Roy.Meteor.Soc.1984,110,783-820.
    [22]Barker E H.A marine boundary layer model for the prediction of fog[J].Boundary Layer Meteor.1977,11.267-294
    [23]Oliver,D.,W.Lewellen,and G.Williamson.The interaction between turbulent and radiative transport in the development of fog and low-level stratus[J].Atmos.Sci.1978,35.301-316.
    [24]周发琇,刘龙太.长江口及济州岛邻近海域综合调查报告(第七节,海雾[J]).山东海洋学院学报.1986,16(1).115-131.
    [25]徐静琦,张正,魏皓,青岛海雾雾滴谱与含水量的观测与分析,海洋湖沼通报,1994.Vol.2.175-178.
    [26]徐静琦,魏皓,张正,顾海涛,青岛市海雾海气通量观测及其作用初探[J],气象学报,1996,Vol.54,No.2,207-215.
    [27]胡瑞金,周发琇.海雾过程中海洋气象条件影响数值研究.青岛海洋大学学报[J].1997,27(3).282-289
    [28]胡瑞金,周发琇.海雾生成过程中平流、湍流和辐射效应研究[J].海洋学报.1998,20(1).25-32
    [29]Estoque,M.A.,A numeiical model of the atmospheric boundary layer[J],Geophys.Res.,1963:68.
    [30]Paul M.,Tag.A Numerical Simulation of Fog Dissipation Using Passive Burner Lines[J].Journal of Applied Meteorology,1979,vol 18,no 11,1455-1471.
    [31]Koziara,Michael C.,Robert J.Renard and William J.Thompson,Estimating Marine Fog Probability Using a Model Output Statistics Scheme[J].Monthly Weather Review,1983,111,2333-2340.
    [32]Musson-Genon,Luc,Numerical Simulation of a Fog Event with a One-dimensional Boundary Layer Model[J].Monthly Weather Review,1987,115,592-607.
    [33]Duynkerke,Peter G.,Radiation Fog:A Comparison of Model Simulation with Detailed Observation[J].Monthly Weather Review,1991,119,324-341.
    [34]Balland,S.p,Golding,B.W.,Smith,R.N.B.,Mesoscale model experimental forecasts of the haar of northeast Scotland[J],Mon.Weather.Rev,1991,119,2107-2123.
    [35]Maria.A.F.,ea tl.,The role of local circulation in summertime convective development and nocturnal fog in SAO PAULO,BRAZIL[J],Boundary-Layer Meteorology,1997,82:135-157.
    [36]Cotton,W.R.ea tl.,The Colorado State University three-dimensional cloud/Mesoscale model,Part Ⅱ:An ice phase parameterization[J],Rech.Atmos.,1982,16:295-320.
    [37]Tripoli,G.J and Cotton,W.R.,The Colorado State University three-dimensional cloud/Mesoscale model,Part Ⅰ:General theoretical framework and sensitivity experiments[J].Rech.Atoms.,1982,16:185-219.
    [38]Wetzel,M.A.,Thompson,W.T.,Vali,G.,Chai,S.K.,Haack,T.,Szumowski,M.J.,Kelly,R.,Evaluation of COAMPS forecasts of coastal stratus using satellite microphysics retrievals and aircraft measurements[J],Weather and Forecast,2001,16:588-599.
    [39]Fanyou Kong,An experimental simulation of a coastal fog-stratus case using COAMPS model[J],Atmospheric Research,2002,64:205-215.
    [40]傅刚,张涛,周发琇.一次黄海海雾的三维数值模拟研究.青岛海洋大学学报[J].2002,32(6)859-867.
    [41]傅刚,王菁茜.一次黄海海雾事件的观测与数值模拟研究-以2004年4月11日为例2004年[J].中国海洋大学学报.2005,34(5).720-725
    [42]樊琦.华南地区雾的数值模拟及其生消机制的研究[M].2003.
    [43]阎俊岳,张秀芝.中国沿海气候[J].气象出版社.1996
    [44]周发琇,王鑫.春季黄海海雾形成的气候特征[J].海洋学报.2004,26(3)28-3
    [45]郭秀英.华南沿海春季海雾与天气型关系的统计分析及预报[J].广东气象.1991,(1)25-28.
    [46]张朝峰.粤东海区海雾的气候特征分析[J].广东气象.2002,(1).20-21.
    [47]Jung,G.H.Open ocean fog forecast:Use of Leipper and Clark indices at ocean station Victer(34°N,134°E)during July-August 1968,1970,1971[J],Tech,Rep.1983.78.
    [48]Leipper,D.F.and D.Koracin.Hot spells and their role in forecasting weather events on the U.S.west coast.Second Conf.on Coastal Atmospheric and Oceanic Prediction and Processes[J],Phoenix,AZ,Desert Research Institute Atmospheric Modeling Group.1998,Paper 4.5.127-132.
    [49]Leipper,D.F.Fog on the United States West Coast:a review[J].Bull.Amer.Meteor.Soc.1994,75.229-240.
    [50]Nieuwstadt F.T.M.,T The steady-state height and resistance laws of the nocturnal boundary layer:Theory compared with cabauw observations[J].Boundary Layer Meteorology,1981,Vol.20,No.1:3-17.
    [51]Plate E.J.,aerodynamic characteristic of atmospheric boundary layer.,AEC CriticalReview Sries,US atomic energy commission,Office of Information Services[J],Available a TID-25465 from NTIS,Springfield,1971,VA22151,190PP.
    [52]Leipper,Coastal fog forecasting at Monterey,California:An open-ended,objective,3 to 6day approach.,Eighth Conf.on Weather Forecasting and Analysis,Denver,CO,Amer[J].Meteor.Soc.,1980,306-309.
    [53]Telford,J.W.and S.K.Chai,Inversions and fog,stratus,and cumulus formation in warm air over cooler water[J].Boundary-Layer Meteorology,1984,Vol.29,pp.109-137.
    [54]Rogers D.P.and J.W.Telford,Metastable stratus tops.Quart[J].Roy.Meteor.Soc.,1986,112,481-500
    [55]Albrecht,B.A.,R.S.Penc,and W.H.Schubert,An observational study of cloud-topped mixed layers[J].Atmos.Sci.,1985,42,800-822.
    [56]Stull R.B.An Introduction to Boundary Layer Meteorology[J].Dordrecht:Kluwer Academic Publishers,1988,666.
    [57]王庚辰,雾微物理结构的观测分析[J],气象学报,1981,39(4),452-459
    [58]杨中秋,许绍祖,耿骠.舟山地区春季海雾的形成和微物理结构[J].海洋学报,1989,11(4):431-438.
    [59]杨连素.青岛近海海雾微物理结构的初步观测[J].海洋科学,1985,9(4):49-50
    [60]李子华,仲良喜,余香仁。西南地区和长江下游的时空分布和物理结构[J],地理学报,1992,47(3):242-251.
    [61]李子华,吴君.重庆市区冬季雾滴谱特征[J].南京气象学院学报,1995,18(1):46-51.
    [62]李子华.中国近40年来雾的研究[J].气象学报,2001,59(5):616-624.
    [63]邹进上,刘长盛,刘文保.大气物理基础[M].北京:气象出版社,1982.
    [64]Cotton W R,Anthes R A,风暴和云动力学[M].北京:气象出版社.1993,331-342.
    [65]Telford J.W.and S.K.Chai,Marine Fog and Its Dissipation over Warm Water[M],1993,Volume 50,Issue 19,pp.3336-3349.

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