1-3-10 大气的结构.ppt

2大气圈的结构 大气的物理性质和化学性质无论在水平方向还是在垂直方向上都是不均匀的 按照大气的化学成分划分 大气垂直方向可分为均质层和非均质层 按照大气的压力结构划分 大气垂直方向可分为气压层和逸散层 按照大气的电离结构划分 大气可分为电离层和磁层 按照温度变化划分 大气在垂直方向可分为 对流层 平流层 中间层 热层以及外层 Verticalchangeinaverageglobalatmospherictemperature Verticalstructureofglobalatmosphere 1 TroposphereLayerintheatmospherefoundfromthesurfacetoaheightofbetween8to16kilometersofaltitude averageheight11kilometers Thetroposphereisthinnestatpolesandgraduallyincreasesinthicknessasoneapproachestheequator Thisatmosphericlayercontainsabout75 ofthetotalmassoftheatmosphere Itisalsothelayerwherethemajorityofourplanet sweatheroccurs MaximumairtemperatureoccursneartheEarth ssurfaceinthislayer Withincreasingaltitudeairtemperaturedropsuniformlywithincreasingheightatanaveragerateof6 5 Celsiusper1000meters commonlycalledtheEnvironmentalLapseRate untilanaveragetemperatureof 56 5 Celsiusisreachedatthetopofthetroposphere 对流层特点 1 对流层的厚度因纬度而有较大差异 低纬度地区约17 18km 中纬度地区约11 12km 高纬度地区约8 9km 2 集中了大气层大部分的质量和几乎全部的水汽3 温度随高度下降 平均每上升100米 气温约下降0 650C4 空气的对流运动明显 特别是夏季以及低纬度地区5 天气复杂多变 水汽蒸发 凝结而成云至雨造成不同的天气现象6 气象要素的水平分布不均匀 受地形 海陆分布等各种性质的下垫面影响 对流层内又可以划分为行星边界层和自由大气 行星边界层特点 地面摩擦力的作用湍流运动大气与下垫面的交换主要在行星边界层内完成行星边界层随天气系统以及时间和空间的变化十分明显 TroposphereTest1 Thetropospherecontainsozone TrueorFalse2 thetropospherecanreach A 110 CB 50 CC 80 C3 Whatpercentageofthetotalmassoftheatmospheredoesthetropospherecontain 4 Howhighisthetropospherefromtheequator 5 Whatoccursinthetroposphere 6 Theheightofthetropopauseceilingisnotconstantintimeorspace TrueorFalse7 Thealtitudeofthetropospherefromthepolesis A 3miles 1英里 1 61公里 B 5milesC 16miles8 Thetroposphereismilesaboveearth A 1to3B 2to7C 5to7D 10to12 AnswersToTest1 False2 C3 75 4 10miles5 weather6 true7 B8 C 2 StratosphereThislayerextendsfromanaveragealtitudeof11to50kilometersabovetheEarth ssurface Thisstratospherecontainsabout19 9 ofthetotalmassfoundintheatmosphere Verylittleweatheroccursinthestratosphere Occasionally thetopportionsofthunderstormsbreachthislayer Thelowerportionofthestratosphereisalsoinfluencedbythepolarjetstreamandsubtropicaljetstream Inthefirst9kilometersofthestratosphere temperatureremainsconstantwithheight Azonewithconstanttemperatureintheatmosphereiscalledanisothermallayer 同温层 Fromanaltitudeof20to50kilometers temperatureincreaseswithanincreaseinaltitude Thehighertemperaturesfoundinthisregionofthestratosphereoccursbecauseofalocalizedconcentrationofozonegasmolecules Thesemoleculesabsorbultravioletsunlightcreatingheatenergythatwarmsthestratosphere Ozoneisprimarilyfoundintheatmosphereatvaryingconcentrationsbetweenthealtitudesof10to50kilometers Thislayerofozoneisalsocalledtheozonelayer 臭氧层 TheozonelayerisimportanttoorganismsattheEarth ssurfaceasitprotectsthemfromtheharmfuleffectsofthesun sultravioletradiation WithouttheozonelayerlifecouldnotexistontheEarth ssurface 平流层特点 1 从对流层顶到50 55km的高度范围是平流层2 气流运动相当稳定 且以水平运动为主3 除少数强对流云伸展到平流层外 很少有天气现象发生4 平流层底层 约9公里厚 温度不随高度变化 称为同温层 5 大气圈大部分的臭氧集中于平流层6 由于臭氧吸收太阳的紫外线辐射 平流层 20 50公里 的温度随高度上升 Test1 Whataretemperaturesoftheupperandlowerlayerofthestratosphere 2 Whatistheupperlayerofthestratospherecalled 3 Alayeroftheearth satmospherethatliesabovethetroposphereiswhat 4 Howcomecloudsaresorareinthestratosphere 5 Howmanymilesdoesthestratospherebeginaboveearth sequator 6 Howmanymilesdoesthestratospherebeginabovetheearth spolarregions 7 Thestratosphereshieldshumansfromwhat AnswerstoTest1 Theupperlayer stemperatureis 67degreesF Thelowerlayertemperatureis28degreesF 2 Stratopause3 Stratosphere4 Thereislittleornomoisture 5 10miles6 6miles7 UltravioletradiationorUVraysfromthesun 3 MesosphereSeparatingthemesospherefromthestratosphereistransitionzonecalledthestratopause Inthemesosphere theatmospherereachesitscoldesttemperatures about 90 Celsius ataheightofapproximately80kilometers Atthetopofthemesosphereisanothertransitionzoneknownasthemesopause 中间层特点 1 从平流层顶到85km的高度范围是中间层2 气温随高度迅速下降3 垂直运动相当激烈 故称之为高空对流层4 因为水汽含量极少 几乎没有云层出现 但有时能看到一种薄而带银白色的夜光云 有人认为它是由极细微的尘埃组成 Noctilucentcloud NLC isanatmosphericphenomenathatissometimesvisibleintheeveningsky athighlatitudes towardthesun justaftersunset inthemidsummermonths TheyformintheMesosphereatanaltitudeof80 85km whichiswhytheyarestillvisibleaftersunsetbecausetheyarelitbythesunfrombelow Nocti night lucent shining NLCarenotthesameasNorthernlightsoraurorawhichareelectricalandoccurhigheratbetween100 300km NLCareclouds believedbeicecrystalsbutbecauseoftheirrarityandaltitudeverylittleisknownaboutthem 夜光云 夜光云 Thisphotowastakenon25Jun2003at2145zoverNorthernFrance Thedarkwispycloudsjustabovethehorizonarecirrus cirrostratusandthenoctilucentcloudsarethewhiteoneswayabove 夜光云 夜光云 Thisphotowastakenat02 00zoverBristolon2Aug03 TheskywasmuchdarkerherebuttheNLCwasstillvisibleatthestartofthetwilight MesosphereTestQuestions1 TheMesosphereisthecoldestatabouthowmanykm inaltitude A 65B 40C 120D 802 TheMesosphereisthe layeroftheatmosphere A hottestB 2ndcoldestC 2ndhottestD coldest3 TheMesosphereextendsfrom50to80km inaltitude Trueorfalse 4 TheairintheMesospheremaymix Trueorfalse 5 ThetoplayeroftheMesosphereiscalledthe A mesopauseB topC mesostopD noneoftheabove6 TheMesospherecanbefoundbetweenthe A stratosphereandthermosphereB thermosphereandmagnetosphereC stratosphereandmagnetosphereD noneoftheabove Testanswers1 D 2 D 3 True4 True5 A 6 A 4 ThermosphereThelastatmosphericlayer asdefinedbyverticaltemperaturechange hasanaltitudegreaterthan80kilometers andiscalledthethermosphere Thethermosphereisthehottestlayerintheatmosphere Heatisgeneratedfromtheabsorptionofsolarradiationbyoxygenmolecules Temperaturesinthislayercanreach1300to1800 Celsius 热层特点 1 热层大致处于中间层顶到600km高度的范围内2 气体在该层在太阳和宇宙辐射的作用下发生电离 形成密度很高的带电粒子 所以热层又称为电离层 3 由于吸收太阳辐射的缘故 该层的温度随高度急剧升高4 在高纬度的晴朗夜空 可看到美丽的极光 这可能是由太阳发出的高速带电粒子激发高空稀薄的空气分子或原子而发光5 电离层会反射无线电波 Ionosphere 电离层 DefinedbyElectricalPropertiesElectricallyChargedIons LayersinMesosphereandThermosphereReflectLowFrequencyAMRadioWaves MagneticFieldinIonosphere CapturesElectricallyChargedIons fromSunauroraborealis NorthernLightsauroraaustralis SouthernLights Aurora Oct 27 28 2001 美丽的极光 美丽的极光 美丽的极光 TestWhatdoesthethermosphereabsorb Whatisthethermospherecompletelyexposedto Whatisthethermosphere Whatistheupperlayerofthethermosphere Whatisanimportantregionofthethermosphere Whatistherangetemperatureinthethermosphere Whatareions Whatisatthetopofthethermosphere WhatpartofthethermosphereabsorbsX raysandcosmicrays Whereareionsfound AnswerKey1 Ultra violetrays2 Thesun sradiation3 Theuppermostlayeroftheatmosphere4 Thethermopause5 Theionosphere6 Belowfreezingto2 200 F7 Electricallycharge