PPTChap2shengtai全球气候系统

1、Chapter 2 The system of global climate第2章 全球气候系统Climate is the state factor that most strongly governs the global patternof ecosystem structure and function气候是状态因素，最强有力地控制着全球的生态系统结构和功能的模式 地形气候母质潜在的生物时间微气候/小气候干扰机制资源功能类型生态系统过程干扰演替生态系统的发展Climate is a key mechanism by which ecosystems interact with the

2、total Earth System气候是一个关键机制,通过生态系统与整个地球系统交互 地球系统科学生态系统生态学生理生态学群落生态学种群生态学环境机制气候学水文土壤学地球化学Major goals in this lecture Understand how the climate system works Enable you to predict the climate any place on Earth这节课的主要目标 理解气候系统是如何工作的 使你能预测地球上任何地方的气候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能量输入=能量输出一半的太阳辐射到达地球大气对短波是透明的，但是会吸收长波辐射（温室效应）大气从底部被加热，通过长波辐射和对流/传递 空间入射太阳辐射短波射出辐射长波对流由H2O、CO2、O3所造成的辐射云层辐射/发射云层、CO2、O3的净吸收对流混合净长

4、波二次辐射由大气造成的后向散射由云层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与云辐射吸收与云辐射直接太直接太阳辐射阳辐射的吸收的吸收云的吸收地表大气H2O、尘埃、O3的吸收感热通量/显热通量潜热通量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身体的温度决定能量释放的波长 太阳辐射具有较高的能量(短波)，容易穿透大气层 地表发射出较低的能量(长波)辐射，可以被大气吸收太阳入射辐射地面输出辐射可见区域吸收率波长The atmosphere is heated from thebottomTherefore it is warmest near the and gets colder with increasingelevation从底部加热大气因此，在底部附近是最温暖的，随着海拔增加会逐渐更冷高度电离层/热层中间层顶中间层/逸散层平流层顶/同温层上线平流层/同温层对流层顶对流层温度珠

6、穆朗玛峰Uneven heating of Earths surface causes atmospheric circulationGreater heating at equator than poles 1. suns rays hit more directly 2. less atmosphere to penetrate地球表面的不均匀加热会导致大气环流赤道比两极加热程度大1.太阳光线直射程度大2.大气渗透少Therefore 1. Net gain of energy at equator 2. Net loss of energy at poles因此1.在赤道地区能量是净增加

7、的2.在两极地区能量是净损耗的大气地轴地表太阳光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空气在赤道上升，在极地下降(垂直循环) 环流圈解释全球降水的分布

8、 地球自转决定了风向(水平循环) (科里奥利力) 热带东风带 (温带)西风带 寒冷空气下沉温暖气流上升寒冷空气下沉温暖气流上升温暖气流上升寒冷空气下沉寒冷空气下沉极锋副热带高压副热带高压极锋极地环流圈极地环流圈哈德莱环流/低纬环流哈德莱环流/低纬环流费雷尔环境圈/中纬度环流圈费雷尔环境圈/中纬度环流圈西风带西风带东北信风东南信风热带辐合带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，空气在寒冷的海洋比陆地下降更强烈 在60N和60S，空气在寒冷的陆地(高压)上下降，在温暖的海洋(低压)上上升 压力梯度在盛行风带造成地理变异纬度经度西伯利亚高压太平洋高压百慕大高压冰岛低压阿留申低压热带辐合带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在夏季时，在60N和60S，空气在寒冷的海洋(高压)上下降，在温暖的陆地(低压)上上升 1.向赤道方向流动的凉爽的空气流在大陆西海岸 2.向极地方向运动的温暖的空气流在大陆东海岸产生行星波动纬度经度热带辐合带西伯利亚低压太平洋高压冰岛低压百慕大高压热低压O

11、cean currents are similar to wind patterns: 1. Driven by Coriolis forces 2. Driven by winds洋流与风的模式相似：1.由科里奥利力驱动2.由风驱动纬度经度西风漂流北大西洋漂流墨西哥湾流 本格拉海流洪堡海流，即秘鲁寒流 黑潮暖流北太平洋漂流 Climate of any region is predictable from topography, wind and ocean currentsAlaskas July temperature任何地区的气候都可以从地形、风力和洋流中预测阿拉斯加七月气温Warmi

12、ng leads to thawing of permafrost (thermokarst) in Alaska气候变暖会导致永久冻土融化(热岩溶)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地球表面的不均匀加热会导致大气环流60%的热传输是通过大气中的暴风，沿压力梯度移动40%是由洋流（输送带）携带的表面(温暖)洋流流向两极 深海(冷)洋流朝赤道方向移动 大气太阳光地轴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洋流从赤道向两极移动40%的“多余热量”由深海水体流动所驱动深海构造发生在格陵兰岛和南极附近 温暖的浅层海流寒冷的含盐深层海流Landform effects on climate Land-water interactions Monsoons Land-sea breezes Mountain effects Rain shadow Effects of aspect Air drainage (inversion)地形对气候的影响陆-水相互作用季风海陆风山脉影响 雨影 坡向的影响空气流泄（反向）Vegetation effects on climate植

15、被对气候的影响 森林森林森林草地草地草地蒸散 /土壤水分蒸发蒸腾损失总量 表面温度 /地表温度 降水 Changes in solar orbit causes long-term variations in solar input to Earth太阳轨道的变化会导致输入地球太阳能的长期变化偏心率/离心率岁差倾斜角时间（数千年前 ）度六月时的日地距离百分比Climate effects on vegetation气候对植被的影响 花粉丰度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)现在地球的气候比过去1000年的任何时候都温暖输入太阳能增加(小幅度变暖影响)2. 硫酸盐气溶胶反射辐射增加(

17、小f幅度降温影响) 3. 温室气体浓度增加(大幅度增温影响)土地覆盖变化造成了更暗的表面(大幅度增暖影响)温度异常Most major greenhouse gases are increasing in atmospheric concentrations最主要的温室气体在大气中的浓度增加 浓度Climate is warming most rapidly at high latitudesThis warming is most pronounced in Siberia and western North America在高纬度地区，气候变暖最快这种气候变暖在西伯利亚和美国北部最为明显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”大气如何变暖？1.更多的太阳辐射地球轨道变化2.短波反射较少硫酸盐气溶胶较少地球表面较暗（土地覆被变化）3.吸收的长波更多更多的“温室气体”空间入射太阳辐射短波射出

19、辐射长波对流由H2O、CO2、O3所造成的辐射云层辐射/发射云层、CO2、O3的净吸收对流混合净长波二次辐射由大气造成的后向散射由云层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与云辐射吸收与云辐射直接太直接太阳辐射阳辐射的吸收的吸收云的吸收地表大气H2O、尘埃、O3的吸收感热通量/显热通量潜热通量Interannual climate variation ENSO eventsTeleconnections carry theseclimate effects throughoutthe globe (e.g., El Nio creates warm winters in AK and Calif)气候年际变化厄尔尼诺事件(大气)遥相关携带这些气候影响遍及全球(例如，厄尔尼诺导致阿拉斯加和加利福尼亚的暖冬)正常情况厄尔尼诺事件高空西风东来信风中高压/温和的高压斜温层/温跃层 斜温层/温跃层 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