气象科技英语精选文档.ppt

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1、气象科技英语本讲稿第一页，共二十四页3.科技英语的语法科技英语的语法英语句子都是由词汇按一定规律组成的，这种语言结构的规律就是语法。学习语法有助于正确使用英语进行写作、说话，也有学习语法有助于正确使用英语进行写作、说话，也有助于阅读和理解英语文献。助于阅读和理解英语文献。在科技英语中常会遇到长而难懂的句子，常常需要借助于语法分析来理解它们。长句子常常是由于在主要成分上附加了许多修饰成分而构成的。我们只要对英语的基本句型非常熟悉，就不难找出长句中的“主要成分”，然后再来处理“附加成分”，问题就容易解决了。3.1英语的基本句型英语的基本句型英语句子是由一些基本成分构成的，这些基本成分包括主语主语(

2、S)，谓语动词，谓语动词(V)，表语，表语(P)，宾语，宾语(O)，补语，补语(C)等。根据构成句子的基本成分的不同可以把英语句子划分成不同的句型。科技英语中常见的句型可分为一般句型和特殊一般句型和特殊句型句型两大类。其中一般句型又可分为主动句主动句(谓语动词为主动语谓语动词为主动语态态)和被动句和被动句(谓语动词为被动语态谓语动词为被动语态)两类。下面是它们的基本格式：本讲稿第二页，共二十四页一般主动句一般主动句：主语主语(S)，谓语动词，谓语动词(V)，表语，表语(P)，宾语，宾语(O)，补语，补语(C)(1)SV 例：Air mass moves.(2)SVP 例：Meteorology

3、 is the science of atmosphere.(3)SVO 例：Computer assesses the observational data.(4)SVO间接O直接 例：The sun gives us light.(5)SVOC 例：We find it very useful.一般被动句一般被动句：(1)SV 例：The balloon is released.(2)SVO 例：A symbol is given each meteorological element.(3)SVC 例：The condition is known as supercooling.特殊句：

4、特殊句：本讲稿第三页，共二十四页(1)疑问句疑问句 例：Is oxygen a gas?(一般疑问句)How(What，Where,When,)does radar work?(特殊疑问句)(2)命令句命令句 例：Explain it,please.(3)存在句存在句 例：There are many forms of energy.(4)省略句省略句 例：T stands for temperature,P for pressure and V for wind speed.(5)强调句强调句 例：Only thus can we do it better.It was Galileo wh

5、o invented thermometer.It is the protons that are positive.(6)先行词先行词it结构结构 例：It is necessary to that We deem it necessary to that(7)比较结构比较结构 例：The more The more The longer the better本讲稿第四页，共二十四页3.2长句的分析长句的分析在基本成分上附加很多修饰成分就构成长句。一般来说，英语修饰成分有两种，即前置修饰和后置修饰。它们分别出现在被修饰成分之前或之后。例如,an important question(前置修饰

6、)，something important(后置修饰)。前置修饰一般容易分析，后置修饰的分析则较麻烦。例如：The air which is moving swiftly usually has high kinetic energy.The swiftly moving air usually has high kinetic energy.上两句中，前一句就比后一句稍麻烦些。因此句子分析的重点不仅在于分析修饰成分，而且主要在于分析后置修饰成分。后置修饰成分除了个别由单词构成外，一般是由从句、短语构成的。能构成修饰成分的从句和短语有：介词短语、不定式短语、现在分词和过去分词短语、形容词从句(

7、定语从句)、副词从句(状语从句)。具体作句子分析时，可按下列步骤进行：本讲稿第五页，共二十四页(1)找出句子中的各种从句从句一般可以凭借引导词，如what,which,who,where,when,how,why等来辨认。其中名词从句常用的引导词有that,whether,if(以上为从属连词)，who,which,what(以上为连接代词)，when,where,how,why(以上为连接副词)。形容词从句常用的引导词有who,which,that(以上为关系代词)，when,where,why(以上为关系副词)。副词从句都由从属连词引导。(2)找出句中(包括从句中)的短语(介词短语、分词短

8、语、不定式等)短语一般凭借介词如of,in，等，不定式标志to，以及分词词尾ing或ed或其它不规则形式的分词来判断。本讲稿第六页，共二十四页(3)然后，分辨这些从句或短语在句子中的作用。即判断它们是句子中的基本成分还是修饰成分。一种分辨方法是将这个从句或短语从句子中删去，若严重损害句子的基本结构或意义，则说明它是基本成分，否则便是修饰成分。(4)将从句、短语纳回到句型中去。再根据逻辑或专业内容，语言或语法要求以及上、下文来判断它们所修饰的成分。对于后置修饰，可以通过“向前推断”的方法来判断。即对该修饰成分之前的第一个、第二个、第三个、词逐个地进行推断，直至找出它所修饰的词为止。本讲稿第七页，

9、共二十四页通过上述分析过程，一般来说全句的语法结构和意义便已清楚了。下面我们来看一个实例：The discovery of the upper air wave as an even more important seat of energy than the associated low level cyclone,followed by the theoretical analyst of Rossby(based on Helmholtzs vorticity theorem)before World War，and of such investigators as Charney,Ea

10、dy,Fjortoft,Eliassen,Starr,Kuo,Lorenz,and Phillips,after the war,has finally led to the establishment of a fairly consistent picture of the large scale motions of the atmosphere,culminating 终极终极in Phillips successful numerical solution for the main properties of the general circulation(1956).在上面的长句中

11、，主要成分是The discovery has led to the establishment.这是SVO结构的一般主动句。所有其它的介词短语、副词及分词从句都是修饰主语、谓语和宾语的。像这一类的长句在读物选的课文中经常可见。作为练习，大家可以自己将它们找出来，进行分析练习，这对提高对长句的阅读理解能力是有好处的。本讲稿第八页，共二十四页3METEOROLOGICAL FORECASTSNew Wordsaviation n.飞行，航空issuance n.发布warning n.警报worldwide a.世界范围的GMT(Greenwich Mean Time)格林尼治标准时间 uppe

12、r-air a.高空的sounding n.探测network n.网状组织watch n.监视WWW(World Weather Watch)世界天气监视网code n.v.电码，编码teletype v.电传打字机telecommunication n.无线电远程通讯GTS(global telecommunication system)全球电(传通)信系统Melbourne n.(澳)墨尔本Moscow n.(苏)莫斯科redistribution n.再分发territory n.地区，领域cooperate v.合作aegis n.保护under the aegis of 在支持下o

13、perationally ad.业务上本讲稿第九页，共二十四页USSR(Union of Soviet Socialist Republics)苏联苏联agency n.代办处，机构代办处，机构European Space Agency 欧洲空间欧洲空间管理站管理站orbiter n.轨道飞行器轨道飞行器coverage n.覆盖覆盖strip n.长带长带NOAA(National Oceanic and Atmospheric Administration)诺阿卫星诺阿卫星(美国国家海洋大气管理局美国国家海洋大气管理局)TIROS(television and infrared obser

14、ving satellite)泰罗斯卫星泰罗斯卫星(电电视红外业务卫星视红外业务卫星)Meteor n.流星卫星流星卫星geosynchronous a.地球同步的地球同步的coverage n.覆盖覆盖strip n.长带长带NOAA(National Oceanic and Atmospheric Administration)诺诺阿卫星阿卫星(美国国家海洋大气管理局美国国家海洋大气管理局)TIROS(television and infrared observing satellite)泰罗斯卫星泰罗斯卫星(电视电视红外业务卫星)Meteor n.流星卫星geosynchronous a

15、.地球同步的geostationary a.相对于地球静止的 GOES(geostationary operational environmental satellite)地球静止业务环境卫星Metosat n.梅多沙特卫星repetitive a.重复的digital a.数字的readout n.读出multi-channel a.多通道的microwave n.微波sensor n.感应器DCS(data collection system)资料收集系统relay v.中继buoy n.浮标站process v.加工，处理，整理facsimile n.传真APT(automatic pi

16、cture transmission)自动图片发送 本讲稿第十页，共二十四页assemble v.组装，汇编telegraphy n.电报Great Exhibition 博览会barometric a.气压的short-range a.短期的extend v.延伸long-range a.长期的revolutionize v.(使)革命化，重大改变nowcasting n.现时预报empirical a.经验的extrapolation n.外推forecaster n.预报员United Kingdom 联合王国routine n.常规conservation n.保守divergence

17、 n.辐散derive v.导出，获得necessitate v.使成为需要，以为条件prognosis(prognoses)n.预测interpolation n.内插smooth v.弄平滑,a.平滑的geopotential a.位势的prediction n.预报spectral a.谱的integrate v.积分nest v.嵌套several-fold ad.翻几番halve v.减半MSL(mean sea level)平均海平面MOS(model output statistics)模式输出统计regression n.回归predictor n.预报因子thundersto

18、rm n.雷暴本讲稿第十一页，共二十四页deficiency n.缺乏satellite-derived a.卫星导出的impose v.强加parameterize v.参数化sub-grid n.次网格unpredictable a.不可预报的precision n.精密，正确scattered a.分散的，稀疏的subjective a.主观的frame-work n.框架topographic a.地形的site-specific a.定点的gust n.阵风tornado n.(陆)龙卷freezing a.冻结的supplement v.补充array n.系列，数组sounder

19、 n.探测器acoustic a.听觉的，声的Doppler(radar)n.多普勒雷达insect n.昆虫refractive a.折射的index(indices)n.指数，索引interpretation n.解释，说明personnel n.全体人员software n.软件prompt a.迅速的，立即行动的，v.激励，提醒shear n.切变downburst n.下击暴流predictability n.可预报性本讲稿第十二页，共二十四页 3METEOROLOGICAL FORECASTS Text National Meteorological Services perfor

20、m a variety of activities in order to provide weather forecasts.The principal ones are data collection,the preparation of basic analyses and prognostic charts of atmosphere conditions for use by local weather offices,the preparation of short and long term forecasts for the public as well as special

21、services for aviation,shipping,agricultural and other commercial and industrial users,and the issuance of severe weather warnings.本讲稿第十三页，共二十四页1 Data sources The data required for forecasting and other services are provided by worldwide standard synoptic reports at 00,06,12 and 18 GMT,similar observ

22、ations made hourly,particularly in support of national aviation requirements,upper air soundings(at 00 and 12 GMT),satellite data and other specialized networks such as radar stations for severe weather.Under the World Weather Watch(WWW)program,synoptic reports are made at some 4,000 land stations a

23、nd by 7,000 ships.There are about 700 stations making upper air soundings(temperature,pressure,humidity and wind).These data are transmitted in code via通过 teletype and radio links in regional or national centers and into the high speed Global Telecommunications System(GTS)connecting World Weather Ce

24、nters in Melbourne,Moscow and Washington and eleven Regional Meteorological Centers for redistribution.Some 157 states and territories cooperate in this activity under the aegis保护of the World Meteorological Organization(WMO).本讲稿第十四页，共二十四页Meteorological information has been collected operationally by

25、 satellites of the United States and USSR since 1965 and,more recently,by the European Space Agency,India and Japan.There are two general categories of weather satellite：polar orbiters providing global coverage twice per 24 hours in orbital strips 带over the poles(such as the United States NOAA and T

26、IROS series,and the USSRs Meteor)and geosynchronous satellites(such as the Geostationary Operational Environmental Satellites(GOES)and Metosat),giving repetitive重复的(30minute)coverage of almost one third of the earths surface in low middle latitudes.Information on the atmosphere is collected as digit

27、al data or direct readout visible and infrared images of cloud cover and sea surface temperature,but also includes global temperature and moisture profiles through the atmosphere obtained from multi-channel infrared and microwave sensors which receive radiation emitted from particular levels in the

28、atmosphere.Additionally,satellites have a data collection system(DCS)that relays中继data on numerous environmental variations from ground platforms or ocean buoys to processing centers;GOES can also transmit processed satellite images in facsimile传真and the NOAA polar orbiters have an automatic picture

29、 transmission(APT)system that is utilized at 900 stations worldwide.本讲稿第十五页，共二十四页 2Forecasting Modern forecasting did not become possible until weather information could be rapidly collected,assembled组装，汇编and processed.The first development came in the middle of the last century with the invention o

30、f telegraphy,which permitted immediate analysis of weather data by the drawing of synoptic charts.These were first displayed in Britain at the Great Exhibition of 1851 Sequences of weather change were correlated with barometric pressure patterns both in space and time by such workers as Fitzroy and

31、Abereroleby,but it was not until later that theoretical models of weather systems were devisednotably the Bjerknes depression model.Forecasts are usually referred to as short-range,medium(or extended)range and long-range.The first two can for present purposes be considered together.本讲稿第十六页，共二十四页Shor

32、t-range forecastingForecasting procedures developed up to the 1950s were based on synoptic principles but,since the 1960s,practices have been revolutionized by numerical forecasting models and the adoption of nowcasting techniques.During the first half of the century,short-range forecasts were based

33、 on synoptic principles,empirical rules and extrapolation of pressure changes.Since 1955 routine forecasts have been based on numerical models.These predict the evolution of physical processes in the atmosphere by determinations of the conservation of mass,energy and momentum.The basic principle is

34、that the rise or fall of surface pressure is related to mass convergence or divergence,respectively,in the overlying air column.本讲稿第十七页，共二十四页Forecast practices in the major national centers are basically similar.The forecasts are essentially derived from twice-daily(00 and 12 GMT)prognoses of atmosp

35、heric circulation.Since most techniques are now largely automated,the analyses of synoptic fields are based on the previous 12-hour forecast maps as a first guess.Three different interpolation methods are used to obtain smoothed,grided data on temperature,moisture,wind and geopotential height for th

36、e surface at standard pressure levels(850,700,500,400,300,250,200 and 100 mb)over the globe.The NMC currently has two basic prediction models:a special model with(6 or)12 layers(from the boundary layer into the upper stratosphere),which is integrated for up to 10 days,and a regionally applicable nes

37、ted grid model with finer horizontal resolution.It should be noted that typically the computer time required increases several-fold when the grid spacing is halved减半.The essential forecast products are MSL pressure,temperature and wind velocity for standard pressure levels,1000500 mb thickness,verti

38、cal motion and moisture content in the lower troposphere,and precipitation amounts.本讲稿第十八页，共二十四页Actual weather conditions are now commonly predicted using the Model Output Statistics(MOS)technique developed by the US National Weather Service.Rather than relating weather variables to the predicted pr

39、essure/height patterns and taking account of frontal models,for example,a series of regression equations are developed for specific locations between the variable of interest and up to 10 predictors calculated by the numerical models.Weather elements so predicted for numerous locations include daily

40、 maximum/minimum temperature,12hour probability of precipitation occurrences and precipitation amount,probability of frozen precipitation,thunderstorm occurrence,cloud cover and surface winds.These forecasts are distributed as facsimile maps and tables to weather offices for local use.本讲稿第十九页，共二十四页E

41、rrors in numerical forecasts arise from several sources.One of the most serious is the limited accuracy of the initial analyses due to data deficiencies.The average over the oceans is sparse and only a quarter of the possible ship reports may be received within 12 hours;even over land more than one-

42、third of the synoptic reports may be delayed beyond 6 hours.However,satellite derived information and aircraft reports can help fill some gaps for the upper air.Another limitation is imposed by the horizontal and vertical resolution of the models and the need to parameterize sub-grid processes such

43、as cumulus convection.The small-scale nature of the turbulent motion of the atmosphere means that some weather phenomena are basically unpredictable,for example,the specific locations of shower cells in an unstable air mass.Greater precision that the showers and bright periods or scattered showers o

44、f the forecast language is impossible with present techniques.The procedure for preparing a forecast is becoming much less subjective,although in complex weather situations the skill of the experienced forecaster still makes the technique almost as much as art as a science.Detailed regional or local

45、 predictions can only be made within the framework of the general forecast situation for the country and demand thorough knowledge of possible topographic or other local effects by the forecaster.本讲稿第二十页，共二十四页NowcastingSevere weather is typically short-lived(2 hr)and,due to its mesoscale character(1

46、00 km),it affects local/regional areas necessitating site specific forecasts.Included in this category are thunderstorms,gust fronts,tornadoes,high winds especially along coasts,over lakes and mountains,heavy snow and freezing precipitation.The development of radar networks,now instruments and high

47、speed communication links has provided a means of issuing warnings of such phenomena.Several countries have recently developed integrated satellite and radar systems to provide information on the horizontal and vertical extent of thunderstorms,for example.Such data are supplemented by networks of au

48、tomatic weather stations(including buoys)that measure wind,temperature and humidity.In addition,for detailed boundary layer and lower troposphere data,there is now an array of vertical soundersacoustic sounders(measuring wind speed and direction from echoes created by thermal eddies),specialized(Dop

49、pler)radar measuring winds in clear air by returns either from insects(35 cm wavelength radar)or from variations in the airs refractive index(10 cm wavelength radar).Nowcasting techniques use highly automated computers and image analysis systems to integrate data from a variety of sources rapidly.In

50、terpretation of the data displays requires skilled personnel and/or extensive software to provide appropriate information.The prompt forecasting of wind shear and downburst hazards at airports is one example of the importance of nowcasting procedures.本讲稿第二十一页，共二十四页Overall,the greatest benefits from