大氣中的化學(xué)反應(yīng)以及輸送

1、大氣中的化學(xué)反應(yīng)以及輸送大氣中的化學(xué)反應(yīng)以及輸送nAtmospheric Motion and Pollutant Transport 大氣移動和污染物輸送大氣移動和污染物輸送qWinds transport atmospheric species away from their points of origin 風(fēng)把大氣物種從它們的原點輸送離開風(fēng)把大氣物種從它們的原點輸送離開qThe scale of atmospheric motions vary from tinny eddies of centimeter or less to huge air mass movements of c

2、ontinental dimensions 大氣移動尺度從微小的幾厘米到小于陸地尺度的巨大空氣團(tuán)運大氣移動尺度從微小的幾厘米到小于陸地尺度的巨大空氣團(tuán)運動。動。 qOrder of 0-100m 0-100米的順序米的順序e.g. indoor air movement, air flow in the urban street canyon, meandering and dispersion of a chimney plume and complicated flow regime in the wake of a large building. 例如室內(nèi)空氣運動，市區(qū)街道的空氣流動，一

3、個煙囪的和復(fù)雜流例如室內(nèi)空氣運動，市區(qū)街道的空氣流動，一個煙囪的和復(fù)雜流動制度的曲徑和散布在大建筑里。動制度的曲徑和散布在大建筑里。 Complicated flow regime behind a building 一座建筑后的復(fù)雜流動制度一座建筑后的復(fù)雜流動制度Microscale Transport微量輸送微量輸送Mesoscale Transport中尺度輸送中尺度輸送nTens to hundreds of kilometersqe.g. and-sea breezes, mountain-valley winds, and migratory high- and low press

4、ure fronts幾十到幾百千米幾十到幾百千米例如，海洋風(fēng)，山谷風(fēng)，遷移高低壓鋒例如，海洋風(fēng)，山谷風(fēng)，遷移高低壓鋒nMountain-valley winds 山谷風(fēng)山谷風(fēng)Mesoscale Transport中尺度輸送中尺度輸送Synoptic Scale 摘要尺度摘要尺度nHundreds to thousands of kilometers 幾百到幾千千米幾百到幾千千米qe.g. motions of weather systems 天氣系統(tǒng)的移動天氣系統(tǒng)的移動Global Scale 全球尺度全球尺度nGlobal Scale: exceeding 5* 103 km 全球尺度：超過

5、全球尺度：超過5* 103 千千米米 ne.g. Hadley circulation 哈德里環(huán)流哈德里環(huán)流Global Scale 全球尺度全球尺度nExceeding 5* 103 kmne.g. Northern Hemisphere Hadley circulationLapse rates and stability 垂直遞減率和穩(wěn)定性垂直遞減率和穩(wěn)定性nLapse rates, stability, and inversions also affect the dispersion of pollutants in the atmosphereqLapse ratesnIn the

6、 stratosphere, the temperature of the ambient air usually decreases with an increase in altitude. This rate of temperature change is called the lapse rate. nEnvironmental engineers can determine this rate for a place and time by sending up a balloon equipped with a thermometer. The balloon moves thr

7、ough the air, and measures the temperature gradient of ambient air, called the ambient lapse rate, the environmental lapse rate, or the prevailing lapse rate.n垂直遞減率，穩(wěn)定性和倒轉(zhuǎn)也影響大氣污染物的分布。n在對流層，空氣的溫度通常隨海拔高度的增加而降低。這種氣溫改變率叫做垂直遞減率。n環(huán)境工程師通過放置了一個溫度計的氣球，可以判斷一個地點時間的這個垂直遞減率。氣球在空氣中移動穿行，測量周圍空氣的氣溫，叫做四周垂直遞減率，或環(huán)境遞減率或

8、普遍遞減率。Lapse rates and Stability 垂直遞減率和穩(wěn)垂直遞減率和穩(wěn)定性定性nTethersonde system for meteorological and pollutant measurement and examples of temperature, relative humidity, wind and ozone profilesnTethersonde系統(tǒng)的氣象測量，污染物測量，氣溫例子，相對濕度，風(fēng)，臭氧Ozone (ppbv), RH (%)WD (degree)Temp (deg C)Altitude (km)030609012009018027

9、0360-60-3003002468101214OzoneWDTempRHHK940408Ozone (ppbv), RH (%)WD (degree)Temp (deg C)Altitude (km)0306090120090180270360-60-3003002468101214OzoneWDTempRHHK940414Ozone (ppbv), RH (%)WD (degree)Temp (deg C)Altitude (km)0306090120090180270360-60-3003002468101214OzoneWDTempRHHK940421Lapse rates and S

10、tability 垂直遞減率和穩(wěn)垂直遞減率和穩(wěn)定性定性nUsing the ideal-gas law and the law of conservation of energy, environmental engineers have established a mathematical ratio for expressing temperature change against altitude under adiabatic conditions. This rate of decrease is termed the adiabatic elapse rate, which is

11、independent of the prevailing atmospheric temperature. n用理想氣體法則和能量守恒法則，環(huán)境工程師建立了一個在絕熱條件下表述氣溫變化和海拔關(guān)系的數(shù)學(xué)比率。這個減少的比率是絕熱垂直遞減率，與普遍大氣溫度相獨立。1.00.5Elevation, kmTT-9.80CTemperature, 0CSuperadiabatic (Unstable)Dry adiabatic (Neutral)Subadiabatic (stable)Isothermal (Stable)Inversion (Stable)Lapse rates and stabi

12、lity 垂直遞減率和穩(wěn)垂直遞減率和穩(wěn)定性定性nDry air, expanding adiabatically, cools at 9.80C per km, which is the dry adiabatic lapse rate. nIn a wet as in a dry adiabatic process, a parcel of air rises and cools adiabatically, but a second factor affects its temperature. Latent heat is released as water vapor condense

13、s within the saturated parcel of rising air. Temperature changes in the air are then due to the liberation of latent heat as well as the expansion of air. nThe wet adiabatic lapse rate (60C/km) is thus less than the dry adiabatic lapse rate. nSince a rising parcel of effluent gases is seldom complet

14、ely saturated or completely dry, the adiabatic lapse rate generally falls somewhere between these two extremes.n干潔空氣，絕熱地膨脹，在9.80C 每千米冷卻，這就是干潔絕熱持之遞減率。n在一個濕的和干的絕熱過程，一個空氣團(tuán)上升和絕熱地冷卻，但是第二個因素影響了它的溫度。燈籠熱以水蒸氣釋放出來，在飽和上升空氣團(tuán)中濃縮?？諝鈿鉁刈兓且驗闊艋\熱運動和空氣膨脹。n濕絕熱垂直遞減率是小于干絕熱垂直遞減率。n因為流出氣體的一個上升空氣團(tuán)很少完全飽和或完全干，所以絕熱的垂直遞減率一般落在這兩個

15、極端之間。Lapse rates and stability 垂直遞減率和穩(wěn)垂直遞減率和穩(wěn)定性定性nAmbient and adiabatic lapse rates are a measure of atmospheric stability. The atmosphere is unstable as long as a parcel of air moving upward cools at a slower rate than the surrounding air and is accelerated upward by buoyancy force. Moving upward,

16、the parcel cools slower and is accelerated downward. Under these conditions, vertical air motions and turbulence are enhanced.nConversely, when a rising parcel of air is cooler than the surrounding air, the parcel settles back to its original elevation. Downward movement produces a warmer parcel, wh

17、ich rises to its original elevation. Under these conditions, vertical movement is dampened out by adiabatic cooling or warming, and the atmosphere is stable. n周圍的和絕熱的垂直遞減率是大氣穩(wěn)定性的測量方式。只要空氣團(tuán)上升時冷卻地比四周空氣慢，和在浮力作用下上升加速，大氣會不穩(wěn)定。移動上升，空氣團(tuán)冷卻得較慢以及向下加速。在這些情況下，垂直空氣移動和騷亂就增加了。n相反，當(dāng)一個上升的空氣團(tuán)比四周的空氣冷卻得快時，空氣團(tuán)就會返回到它的原起點。

18、向下運動產(chǎn)生一個較暖的空氣團(tuán)，它上升到它的原上升點。在這些情況下，垂直運動絕熱冷卻或增溫，大氣時穩(wěn)定的。Lapse rates and stability 垂直遞減率和穩(wěn)垂直遞減率和穩(wěn)定性定性nThe boundary line between stability and instability is the dry adiabatic lapse rate line. When the ambient lapse rate exceeds the adiabatic lapse rate, the ambient lapse rate is termed superadiabatic, an

19、d the atmosphere is highly unstable. nWhen the two lapse rates are equal, the atmosphere is neutral.nWhen the ambient lapse rate is less than the dry adiabatic lapse rate, the ambient lapse rate is termed subadiabatic, and the atmosphere is stable. nIf the air temperature is constant throughout a la

20、yer of atmosphere, the ambient lapse rate is zero, the atmosphere is described as isothermal, and the atmosphere is stable.nWhen the temperature of ambient air increases (rather than decrease) with altitude, the lapse rate is negative, or inverted, from the normal state. n穩(wěn)定的和不穩(wěn)定的界限就是干的絕熱垂直率線。當(dāng)四周垂直遞

21、減率超過絕熱垂直遞減率時，四周垂直遞減率就是超級絕熱的，大氣是高度不穩(wěn)定的。n當(dāng)兩個垂直遞減率相等時，大氣是中性的。n當(dāng)四周垂直遞減率少于干的絕熱垂直遞減率時，四周垂直遞減率為潛絕熱的，大氣時穩(wěn)定的。n如果大氣層的空氣溫度是恒定不變的，四周垂直遞減率為0，那么大氣被描述為等溫的，大氣是穩(wěn)定的。n當(dāng)四周空氣溫度隨海拔上升，那么垂直遞減率與正常狀態(tài)是消極，或相反的。Lapse rates and stability 垂直遞減率和穩(wěn)垂直遞減率和穩(wěn)定性定性nA negative lapse rate occurs under conditions referred to as an inversion

22、, a state in which warm air blankets colder air. Thermal or temperature inversions represent a high degree of atmospheric stability. nAn inversion is an extreme subadiabatic condition, thus almost no vertical air movement occurs.n一個消極垂直遞減率在相反的條件下發(fā)生，這種情況下暖氣團(tuán)覆蓋冷氣團(tuán)。n相反的情況就是一個極潛絕熱條件，那么幾乎不發(fā)生垂直空氣運動。Potent

23、ial Temperature 潛在溫度潛在溫度nA useful concept in determining stability in the atmosphere is potential temperature. This is a means of identifying the dry adiabat to which a particular atmospheric combination of temperature and pressure is related. 一個決定大氣穩(wěn)定性的有用概念是潛熱。這是一個在特別的大氣溫度結(jié)合和氣壓相關(guān)的地方，辨別干的絕熱。nThe pot

24、ential temperature is found from: 潛在溫度來自：nwhere T is temperature and P is air pressure (in millibars, mb). P0 is a reference pressure. Usually P0 is set to 1000 mb, but sometimes for boundary layer work the surface pressure is used instead. This potential temperature is the same as the temperature t

25、hat a parcel of dry air would have if brought dry adiabatically to the pressure in the surface.nT是溫度，P是氣壓。 P0是一個參考?xì)鈮?。通常設(shè)定為1000mb，但有時候的界限層工作也用到地表壓力。這個潛熱的溫度與當(dāng)把干空氣團(tuán)在干絕熱條件下達(dá)到與地面壓強下的溫度相同。288. 00)/(PPTPotential Temperature 潛熱潛熱nIf the potential temperature decreases with height, the atmosphere is unstable

26、. 如果潛熱隨高度升高而降低，大氣是不穩(wěn)定的。如果潛熱隨高度升高而降低，大氣是不穩(wěn)定的。nIf the potential temperature increases with height, the atmosphere is stable.n如果潛熱隨高度而升高，大氣是穩(wěn)定的。如果潛熱隨高度而升高，大氣是穩(wěn)定的。nIf the potential temperature is constant with height, the atmosphere is neutral.n如果潛熱不隨高度改變，大氣是中性的。如果潛熱不隨高度改變，大氣是中性的。Topography 平流層平流層nThe t

27、opographic features of a region include both natural (hills, canals, oceans, rivers, lakes, and foliages) and manmade (cities, bridges, roads and canals) elements in a region. n一個地區(qū)的平流層特征包括自然的（小山，溝渠，海洋，河流，湖泊，植物）和人造的（城市，一個地區(qū)的平流層特征包括自然的（小山，溝渠，海洋，河流，湖泊，植物）和人造的（城市，橋，道路，運河）的因素。橋，道路，運河）的因素。nThe prime sign

28、ificance of topography is its effects on meteorological elements, particularly the local or small-scale circulations that develop. n平流層主要的重要性是它在氣象因素上的作用，特別是地區(qū)的或小尺度循環(huán)。平流層主要的重要性是它在氣象因素上的作用，特別是地區(qū)的或小尺度循環(huán)。nThese circulations contribute favorably or unfavorably to the transport and dispersion of the pollu

29、tants.n這些循環(huán)對污染物的輸送和分布有好的和不好的影響。這些循環(huán)對污染物的輸送和分布有好的和不好的影響。LAND-SEA BREEZE 陸地海洋風(fēng)陸地海洋風(fēng)nIn the daytime, land heats rapidly, which heats the air above it. The water temperature remains relatively constant. The air over the heated land surface rises producing low pressure compared with the pressure over wat

30、er. nThe resulting pressure gradient produces a surface flow off the water toward land.nThis circulation can extend to a considerable distance inland. After sunset and several hours of cooling by radiation, the land mass is cooler than the water temperature. Then, the reverse flow pattern develops,

31、resulting in a wind off the land. n在白天，地面增熱快，使地面上層空氣增熱。水溫保持相對穩(wěn)定。與水面壓力相比，在增熱的土地表面空氣上升而產(chǎn)生低壓。n這氣壓梯度產(chǎn)生了一個從水面到陸地表面流。n這個循環(huán)可以延伸到內(nèi)地一個相當(dāng)大的距離。在日落后和幾個小時的輻射降溫，地面比水面溫度要低。那么相反的活動模式開始了，形成了陸地到海洋的風(fēng)。Cool SeaWarm LandWarm and dirty airZ(m)10005000XClearer airMOUNTAIN-VALLEY WINDS山脈峽谷風(fēng)nValleys, especially those in moun

32、tains regions (e.g., Hong Kong), produce their own local wind systems as a result of thermal differences.nBy day, the air above the slopes and floor of the valley will be heated by the underlying surface to a temperature well above the center of the valley. As a result, shallow and unstable upslope

33、flow arises, and to maintain continuity a closed circulation develops across the valley involving air sinking in the valley center.nCommonly the uplift along the slopes is at speeds of 2 to 4 m s-2 with a maximum at about 20-40 m above the surface. It can lead to the formation of convective clouds a

34、long the valley ridges. n峽谷，特別是那些在山脈地區(qū)的（例如香港），由于熱量不同，產(chǎn)生它們各自的當(dāng)?shù)氐娘L(fēng)系統(tǒng)。n在白天，在斜坡上和峽谷地面的空氣會被下面的地表加熱達(dá)到峽谷中心的溫度。所以，淺的和不穩(wěn)定的上坡氣流上升，為保持一個閉合循環(huán)的連續(xù)性n一般地，沿著斜坡的上升流的速度是2 to 4 m s-2 ，在地表的最大速度是20-40 m 。它可使對流的云在山谷邊沿形成。(a)(b)Valley inversionURBAN-HEAT-ISLAND EFFECT市區(qū)熱島效應(yīng)nMost cities are anthropogenic sources of heat and

35、pollution. nThe downtown areas are covered by a large percentage of asphalt and concrete, which are usually dry, waterproof surfaces with albedoes and heat capacities that store incoming solar radiation much more than the surrounding countryside. nThus, surface-layer air in cities is generally warme

36、r than that of their surroundings. The magnitude of the temperature difference between urban and its rural areas is called urban heat island. nThe greatest temperature differences between urban and rural areas are usually observed during the night. n大多數(shù)城市都是人為的熱和污染的源。n市區(qū)中心被大比例的干的瀝青和混凝土覆蓋，有漫反射系數(shù)和增熱能力的

37、防水表面可儲存比周圍鄉(xiāng)村更多的太陽輻射。n那么，城市里的表面層空氣的溫度比它們四周的空氣高。市區(qū)與郊區(qū)溫度的大小不同，叫做市區(qū)熱島。n最大的溫度差異通常發(fā)生在晚上。URBAN-HEAT-ISLAND EFFECT市區(qū)熱島效應(yīng)nCities with a population of about 1000 have been observed to have maximum temperature excesses (compared to the surrounding rural area) of 2 to 30C, while cities of a million or more inha

38、bitants have been known to generate excesses of 8 to 120C. n有人口約1000人的城市發(fā)現(xiàn)最高溫度超過2到30C（與周圍郊區(qū)相比），而人口多于100萬的城市的溫度比周圍郊區(qū)高出8到120C。05101520T(0C)12180612Local time (h)UrbanRuralURBAN-HEAT-ISLAND EFFECT市區(qū)熱島效應(yīng)nIn many cases, heat from the city is sufficient to maintain a shallow convective mixed layer at nigh

39、t, even while a substantial stable boundary layer has developed over the surrounding countryside. nThe intensity of the urban heat island depends on various factors, such as the size and morphology of the city. nThe primary factors are the increased absorption of heat by buildings due to their mass

40、and canyon-like geometry, and the reduction in vegetation. nSince the generation and consumption of fuels for space heating/cooling is linked to the release of air pollutants that create urban smog and contribute to greenhouse gas emissions, interest in this topic is high in air pollution problems.n

41、Similar to the formation of sea-land breezes, an urban-heat island circulation may develop over cities due to the differential temperatures between the cities and their rural areas.n在許多情況下，來自城市的熱量足夠保持夜間淺對流的混合層，甚至一個實質(zhì)上穩(wěn)定的界層在周圍鄉(xiāng)村形成發(fā)展了。n市區(qū)熱島的集中度依靠不同的因素，例如大小和城市的形態(tài)。n重要因素是建筑物對熱的吸收增加了，因為它們的物質(zhì)和“峽谷”幾何，以及植被的減

42、少。n因為作為空間加熱和降溫的燃料的集中和消耗與產(chǎn)生市區(qū)煙霧和增加溫室氣體的空氣污染物的排放是相關(guān)的，這個話題的研究是空氣污染問題。n與海洋陸地風(fēng)相似，市區(qū)熱島循環(huán)可以延伸到其他城市因為城市與它們周圍郊區(qū)的溫度差異。Boundary Layer Structure界層結(jié)構(gòu)界層結(jié)構(gòu)nOver land surfaces in high pressure regions the BL has a well defined structure that evolves with the diurnal cycle. The three major components of this structu

43、re are the mixed layer, the residual layer, and the stable BL. When clouds are present in the mixed layer, it is further subdivided into a subcloud layer. In addition, the bottom 10% of the boundary layer is called the surface layer, regardless of whether it is part of a mixed layer or stable BL.n在地

44、表高壓地區(qū)，BL有一個發(fā)展得很好的日循環(huán)界層結(jié)構(gòu)。這個結(jié)構(gòu)的三個主要構(gòu)成物是：混合層，停留層，和穩(wěn)定層。當(dāng)云層出現(xiàn)在混合層時，它將進(jìn)一步劃分成一個云下層。另外，界層底部的10叫做表面層，不管它是否屬于混合層或穩(wěn)定層。Convective Mixed layerEntrainment ZoneSurface LayerStable Boundary LayerSurface layerResidual layerSurface LayerMixed LayerFree AtmosphereCapping Inversion012Height (km)NoonSunsetSunriseNoonMi

45、dnightMixed Layer 混合層混合層nThe turbulence in the mixed layer (ML) is usually convective driven, although a nearly well-mixed layer can form in regions of strong winds. The major convective source is the heat transfer from a warm ground surface.n On initially cloud-free days, however, ML growth is tied

46、 to solar heating of the ground. Starting about a half hour after sunrise, a turbulent ML begins to grow in depth. This ML is characterized by intense mixing in a statically unstable situation where thermals of warm air rise from the ground. The ML reaches its maximum depth in late afternoon.nThe re

47、sulting turbulence tends to mix heat, moisture, and momentum uniformly in the vertical. Pollutants emitted from smoke stacks exhibit a characteristic looping as those portions of the effluent emitted into warm thermals begin to rise.n雖然混合層的騷亂通常是對流的驅(qū)使，一個很好的混合層可以形成強風(fēng)的地區(qū)。主要的對流源來自暖地表的熱量傳輸。n然而在無云的日子，混合層增

48、長與太陽光增溫緊緊相關(guān)。在日出后半小時，一個騷動的混合層開始增長?；旌蠈拥奶卣魇歉叨然旌系撵o止的不穩(wěn)定狀況，這種情況下的暖空氣的熱量從地面上升?；旌蠈釉谙挛邕_(dá)到它的最大深度。n這騷動傾向于垂直的混合熱，濕度，和不變的動力。煙囪排放的污染物展現(xiàn)了典型的環(huán)形當(dāng)排放到暖熱氣流的流出物部分開始上升。Residual layer 停留層停留層nAbout a half hour before sunset the thermals cease to form, allowing turbulence to decay in the formerly well-mixed layer. The resul

49、ting layer of air is sometimes called the residual layer (RL) because its initial mean state variables and concentration variables are the same as those of the recently-decayed mixed layer.nIn the absence of advection, passive tracers (e.g., air pollutants) dispersed into the daytime mixed layer wil

50、l remain aloft in the RL during the night. The RL is neutrally stratified, resulting in turbulence that is nearly of equal intensity in all directions. nAs a result, smoke plumes emitted into the RL tend to disperse at equal rates in the vertical and lateral directions, creating a cone-shaped plume.

51、 n大約日落前半小時，上升的熱氣流停止形成，允許之前形成的混合層的騷亂衰減。這產(chǎn)生的空氣層有時候叫做停留層因為它的初始狀態(tài)變量和濃度變量與那些最近衰減混合層的一樣。n在沒有水平對流下，分布在白天混合層的被動跟蹤物（如空氣污染物）在夜晚會保持在停留層的高處。停留層是中立地分層的，于是產(chǎn)生了近乎所有方向的相等集中度的騷亂。n因此，排放到停留層的煙霧傾向于以相等比率分布在水平的和垂直的方向，產(chǎn)生一個圓錐體的煙羽。The static stability decreases with height in the nocturnal boundary layer, gradually blending

52、into the neutrally-stratified residual layer aloft. Smoke emissions into the stable air fan out in the horizontal with little vertical dispersion other than wavelike oscillations. Smoke emissions in the neutral residual-layer air spread with an almost equal rate in the vertical and horizontal, allow

53、ing the smoke plume to assume a cone-like shape.靜態(tài)穩(wěn)定性在夜間的界層隨著高度升高而降低，逐漸融合到中立分層的停留層高處。排放到穩(wěn)定空氣中的煙在海平線中成扇形展開，有少量垂直分布，而沒有波狀振動。在中性停留層排放的煙在垂直方向和水平方向的速率幾乎相等，這就允許煙羽形成一個圓錐體的形狀。Free atmosphereCapping inversionNear neutralWeakly stableStrongly stablefanningStatic stability 靜態(tài)穩(wěn)定性Stable Boundary Layer 穩(wěn)定界層穩(wěn)定界層nA

54、s the night progresses, the bottom portion of the residual layer is transformed by its contact with the ground into a stable boundary layer. This is characterized by statically stable air with weaker, sporadic turbulence. The wind at ground level frequently becomes lighter or calm at night. nThe sta

55、tically stable air in this layer tends to suppress turbulence. nPollutants emitted into the stable layer disperse relatively little in the vertical. They disperse more rapidly, or “fan out”, in the horizontal. This behavior is called fanning. Sometimes at night when winds are lighter, the effluent m

56、eanders left and right as it drifts downwind.n在夜晚，停留層底部部分接觸到地面時轉(zhuǎn)換成一個穩(wěn)定的界層。這是一個有著較弱的，零星的騷亂的靜態(tài)的穩(wěn)定空氣的特征。地面的風(fēng)在夜晚通常變得更輕，更靜。n這層的靜態(tài)的穩(wěn)定空氣傾向于壓制騷亂。n排放到這個穩(wěn)定層的污染物在垂直方向分散得相對較少。它們分散得更快，或在水平方向成扇形展開。這種行為叫做扇形展開。當(dāng)風(fēng)更輕的夜晚，排除物在它們順風(fēng)漂移時左右彎曲流動。Atmospheric Lifetimes 大氣生命周期大氣生命周期nThe physical principle governs the behavior o

57、f a chemical: Conservation of MassnRate of the species flowing in (Fin) -Rate of the species flowing out (Fout) + Rate of introduction (emission) of the species (E) - Rate of removal of the species (R) = Rate of accumulation of the species in the imaginary volume (dQ/dt)n物理原則控制化學(xué)物的行為：質(zhì)量的守衡物理原則控制化學(xué)物的

58、行為：質(zhì)量的守衡n物種的進(jìn)入率物種的離開率物種的產(chǎn)生率物種的除去率物物種的進(jìn)入率物種的離開率物種的產(chǎn)生率物種的除去率物種在假設(shè)體積的積累率。種在假設(shè)體積的積累率。Box ModelAtmospheric Lifetimes 大氣生命周期大氣生命周期ndQ/dt = (Fin - Fout) + (P - R)nThe balance must hold from the smallest cube to the entire atmosphere. 這個平衡的把持必須從最小的立方到整個大氣。這個平衡的把持必須從最小的立方到整個大氣。nIn a steady-state condition, d

59、Q/dt = 0nFin + P = Fout + R -(1)nFor the entire atmosphere, Fin = Fout =0 and in steady-state, nP=RAtmospheric Lifetimes 大氣生命周期大氣生命周期nThe average residence time 平均停留時間平均停留時間n = Q/(R+Fout) orn = Q/(P+Fout), since (1)nIf the entire atmosphere is taken as the reservoir, then under steady-state conditio

60、ns 如果整個大氣被看作是儲存器的話，那么在穩(wěn)定狀態(tài)條件下如果整個大氣被看作是儲存器的話，那么在穩(wěn)定狀態(tài)條件下nQ/R=Q/PnOH radical has a lifetime less than 0.01 s and a spatial transport scale of around 1 cm OH自由有的生命周期少于自由有的生命周期少于0.01秒，一個空間傳輸尺度約秒，一個空間傳輸尺度約1厘米厘米nCH4 is 10 years and entire Earth.Atmospheric Lifetimes 大氣生命周期大氣生命周期Spatial and Temporal Scales