PPTChap2shengtai全球氣候系統(tǒng)

1、Chapter 2 The system of global climate第2章 全球氣候系統(tǒng)Climate is the state factor that most strongly governs the global patternof ecosystem structure and function氣候是狀態(tài)因素，最強有力地控制著全球的生態(tài)系統(tǒng)結(jié)構(gòu)和功能的模式 地形氣候母質(zhì)潛在的生物時間微氣候/小氣候干擾機制資源功能類型生態(tài)系統(tǒng)過程干擾演替生態(tài)系統(tǒng)的發(fā)展Climate is a key mechanism by which ecosystems interact with the

2、total Earth System氣候是一個關(guān)鍵機制,通過生態(tài)系統(tǒng)與整個地球系統(tǒng)交互 地球系統(tǒng)科學(xué)生態(tài)系統(tǒng)生態(tài)學(xué)生理生態(tài)學(xué)群落生態(tài)學(xué)種群生態(tài)學(xué)環(huán)境機制氣候?qū)W水文土壤學(xué)地球化學(xué)Major goals in this lecture Understand how the climate system works Enable you to predict the climate any place on Earth這節(jié)課的主要目標(biāo) 理解氣候系統(tǒng)是如何工作的 使你能預(yù)測地球上任何地方的氣候Energy in = energy outHalf of solar radiationreaches Ea

3、rthThe atmosphere is transparent to shortwave but absorbs longwave radiation(greenhouse effect)The atmosphere is heated from the bottom by longwave radiation and convection能量輸入=能量輸出一半的太陽輻射到達(dá)地球大氣對短波是透明的，但是會吸收長波輻射（溫室效應(yīng)）大氣從底部被加熱，通過長波輻射和對流/傳遞 空間入射太陽輻射短波射出輻射長波對流由H2O、CO2、O3所造成的輻射云層輻射/發(fā)射云層、CO2、O3的凈吸收對流混合凈長

4、波二次輻射由大氣造成的后向散射由云層造成的后向散射地表反射天空漫反射的天空漫反射的吸收與云輻射吸收與云輻射直接太直接太陽輻射陽輻射的吸收的吸收云的吸收地表大氣H2O、塵埃、O3的吸收感熱通量/顯熱通量潛熱通量The temperature of a body determineswavelengths of energy emittedSolar radiation has high energy (shortwave) that readily penetratesthe atmosphereEarth emits low-energy (longwave)radiation that is

5、 absorbed by theatmosphere身體的溫度決定能量釋放的波長 太陽輻射具有較高的能量(短波)，容易穿透大氣層 地表發(fā)射出較低的能量(長波)輻射，可以被大氣吸收太陽入射輻射地面輸出輻射可見區(qū)域吸收率波長The atmosphere is heated from thebottomTherefore it is warmest near the and gets colder with increasingelevation從底部加熱大氣因此，在底部附近是最溫暖的，隨著海拔增加會逐漸更冷高度電離層/熱層中間層頂中間層/逸散層平流層頂/同溫層上線平流層/同溫層對流層頂對流層溫度珠

6、穆朗瑪峰Uneven heating of Earths surface causes atmospheric circulationGreater heating at equator than poles 1. suns rays hit more directly 2. less atmosphere to penetrate地球表面的不均勻加熱會導(dǎo)致大氣環(huán)流赤道比兩極加熱程度大1.太陽光線直射程度大2.大氣滲透少Therefore 1. Net gain of energy at equator 2. Net loss of energy at poles因此1.在赤道地區(qū)能量是凈增加

7、的2.在兩極地區(qū)能量是凈損耗的大氣地軸地表太陽光Air rises at equator and subsides at poles(vertical circulation)Circulation cells explain global distribution of rainfallEarths rotation determineswind direction (horizontal circulation) (Coriolis force) tropical easterlies temperate westerlies空氣在赤道上升，在極地下降(垂直循環(huán)) 環(huán)流圈解釋全球降水的分布

8、 地球自轉(zhuǎn)決定了風(fēng)向(水平循環(huán)) (科里奧利力) 熱帶東風(fēng)帶 (溫帶)西風(fēng)帶 寒冷空氣下沉溫暖氣流上升寒冷空氣下沉溫暖氣流上升溫暖氣流上升寒冷空氣下沉寒冷空氣下沉極鋒副熱帶高壓副熱帶高壓極鋒極地環(huán)流圈極地環(huán)流圈哈德萊環(huán)流/低緯環(huán)流哈德萊環(huán)流/低緯環(huán)流費雷爾環(huán)境圈/中緯度環(huán)流圈費雷爾環(huán)境圈/中緯度環(huán)流圈西風(fēng)帶西風(fēng)帶東北信風(fēng)東南信風(fēng)熱帶輻合帶At 30 N & S, air descends more strongly over cold ocean than over landAt 60 N & S, air descends over cold land (high press

9、ure) and rises over warm ocean (low pressure)Pressure gradients create geographic variation in prevailing winds在30N和30S，空氣在寒冷的海洋比陸地下降更強烈 在60N和60S，空氣在寒冷的陸地(高壓)上下降，在溫暖的海洋(低壓)上上升 壓力梯度在盛行風(fēng)帶造成地理變異緯度經(jīng)度西伯利亞高壓太平洋高壓百慕大高壓冰島低壓阿留申低壓熱帶輻合帶In summer at 60 N & S, air descends over cold ocean (high pressure) and

10、 rises over warm land (low pressure) 1. Cool equator-ward flow of air on W coast of continents 2. Warm poleward flow of air on E coasts of continentsCreates planetary waves在夏季時，在60N和60S，空氣在寒冷的海洋(高壓)上下降，在溫暖的陸地(低壓)上上升 1.向赤道方向流動的涼爽的空氣流在大陸西海岸 2.向極地方向運動的溫暖的空氣流在大陸東海岸產(chǎn)生行星波動緯度經(jīng)度熱帶輻合帶西伯利亞低壓太平洋高壓冰島低壓百慕大高壓熱低壓O

11、cean currents are similar to wind patterns: 1. Driven by Coriolis forces 2. Driven by winds洋流與風(fēng)的模式相似：1.由科里奧利力驅(qū)動2.由風(fēng)驅(qū)動緯度經(jīng)度西風(fēng)漂流北大西洋漂流墨西哥灣流 本格拉海流洪堡海流，即秘魯寒流 黑潮暖流北太平洋漂流 Climate of any region is predictable from topography, wind and ocean currentsAlaskas July temperature任何地區(qū)的氣候都可以從地形、風(fēng)力和洋流中預(yù)測阿拉斯加七月氣溫Warmi

12、ng leads to thawing of permafrost (thermokarst) in Alaska氣候變暖會導(dǎo)致永久凍土融化(熱巖溶)在阿拉斯加 Uneven heating of Earths surface causes atmospheric circulation60% of heat transport is carried by atmosphere through storms thatMove along pressure gradients40% is carried by ocean currents (conveyor belt) surface (war

13、m) currents move poleward deep (cold) currents move equatorward地球表面的不均勻加熱會導(dǎo)致大氣環(huán)流60%的熱傳輸是通過大氣中的暴風(fēng)，沿壓力梯度移動40%是由洋流（輸送帶）攜帶的表面(溫暖)洋流流向兩極 深海(冷)洋流朝赤道方向移動 大氣太陽光地軸Ocean currents move 40% of “excess heat” from equator to polesDriven by circulation of deep ocean waters Deepwater formation occurs near Greenland

14、 and in Antarctic洋流從赤道向兩極移動40%的“多余熱量”由深海水體流動所驅(qū)動深海構(gòu)造發(fā)生在格陵蘭島和南極附近 溫暖的淺層海流寒冷的含鹽深層海流Landform effects on climate Land-water interactions Monsoons Land-sea breezes Mountain effects Rain shadow Effects of aspect Air drainage (inversion)地形對氣候的影響陸-水相互作用季風(fēng)海陸風(fēng)山脈影響 雨影 坡向的影響空氣流泄（反向）Vegetation effects on climate植

15、被對氣候的影響 森林森林森林草地草地草地蒸散 /土壤水分蒸發(fā)蒸騰損失總量 表面溫度 /地表溫度 降水 Changes in solar orbit causes long-term variations in solar input to Earth太陽軌道的變化會導(dǎo)致輸入地球太陽能的長期變化偏心率/離心率歲差傾斜角時間（數(shù)千年前 ）度六月時的日地距離百分比Climate effects on vegetation氣候?qū)χ脖坏挠绊?花粉豐度Earths climate is now warmer than at any time in the last 1000 years 1. increa

16、sed solar input (small warming effect) 2. Increased sulfate aerosols reflects radiation (small cooling effect) 3. Increased greenhouse gas concentrations (large warming effect) 4. Land-cover change creates a darker surface (large warming effect)現(xiàn)在地球的氣候比過去1000年的任何時候都溫暖輸入太陽能增加(小幅度變暖影響)2. 硫酸鹽氣溶膠反射輻射增加(

17、小f幅度降溫影響) 3. 溫室氣體濃度增加(大幅度增溫影響)土地覆蓋變化造成了更暗的表面(大幅度增暖影響)溫度異常Most major greenhouse gases are increasing in atmospheric concentrations最主要的溫室氣體在大氣中的濃度增加 濃度Climate is warming most rapidly at high latitudesThis warming is most pronounced in Siberia and western North America在高緯度地區(qū)，氣候變暖最快這種氣候變暖在西伯利亞和美國北部最為明顯H

18、ow can the atmosphere warm? 1. More solar radiationvariation in Earths orbit 2. Less reflected shortwaveless sulfate aerosolsdarker surface of Earth (land-cover change) 3. More absorbed longwave more “greenhouse gases”大氣如何變暖？1.更多的太陽輻射地球軌道變化2.短波反射較少硫酸鹽氣溶膠較少地球表面較暗（土地覆被變化）3.吸收的長波更多更多的“溫室氣體”空間入射太陽輻射短波射出

19、輻射長波對流由H2O、CO2、O3所造成的輻射云層輻射/發(fā)射云層、CO2、O3的凈吸收對流混合凈長波二次輻射由大氣造成的后向散射由云層造成的后向散射地表反射天空漫反射的天空漫反射的吸收與云輻射吸收與云輻射直接太直接太陽輻射陽輻射的吸收的吸收云的吸收地表大氣H2O、塵埃、O3的吸收感熱通量/顯熱通量潛熱通量Interannual climate variation ENSO eventsTeleconnections carry theseclimate effects throughoutthe globe (e.g., El Nio creates warm winters in AK and Calif)氣候年際變化厄爾尼諾事件(大氣)遙相關(guān)攜帶這些氣候影響遍及全球(例如，厄爾尼諾導(dǎo)致阿拉斯加和加利福尼亞的暖冬)正常情況厄爾尼諾事件高空西風(fēng)東來信風(fēng)中高壓/溫和的高壓斜溫層/溫躍層 斜溫層/溫躍層 上涌冷海水上涌暖海水The Pacific Ocean strongly influences the climate system becauseIt is the largest ocean basinNormal ocean current an