INTRODUCTION TO THE ATMOSPHERE TERMINOLOGY Weather The state

INTRODUCTION TO THE ATMOSPHERE 大氣系統介紹

TERMINOLOGY Weather 天氣: The state of the atmosphere, mainly with respect to its effects on life and human activities. 大氣的狀態，主要關心在其對於生命及人類活動的影響 Climate 氣候: The long-term manifestations of the weather. It is represented by the statistical collective of weather conditions over a specified (long) interval of time, usually several decades (e. g. , 30 years). 天氣的長時間表現。

The Earth System 地球系統 Four spheres of the earth • Hydrosphere (Water) ü 地底數公里至大氣層 ü 97%鹽水(Salty wather) ü 主宰地球溫度 • Biosphere (Living Things) ü 有生命所在處 ü 橫跨其他三區 • Lithosphere (Geosphere, Land) ü 地殼及上部地函 • Atmosphere (Air) ü 氮(78%)、氧(21%)、其他(1%， 二氧化碳、氬…) • Energy reaches the Earth from an external source and eventually returns to space as long wavelength radiation.

The Hydrologic Cycle 水文循環 Evaporation 蒸發 Transpiration 蒸散 Depiction of the open system by a box model.

大氣(層)是什麼 The atmosphere: The envelope of gasses surrounding the earth and bound to it more or less permanently by the earth’s gravitational field. 包圍著地球並受地球引力束縛的氣 體，。 大氣層大致可分為 對流層( Troposphere)、 平流層 ( Stratosphere)、 中氣層 ( Mesosphere)、 熱氣層(Thermosphere)/ 電離層 ( Ionosphere) 大氣垂直分層 (圖片來源：Ahrens，p. 14，Fig. 1. 10)

Vertical temperature profile of the atmosphere

Monitoring the Ozone Hole https: //www. youtube. com/watch? time_continue=113 &v=u. Ve. TJSIb. Gm 8

大氣壓力隨高度變化 Averaged global MSL (Mean Sea. Level ) pressure 1013. 25 mb (毫巴) 1大氣壓(atm)=101, 325帕(pa) =1013. 25百帕=76公分水銀柱高 =760托(Torr) 1巴(bar)=100, 000 pa Commercial aircraft 民航機 (圖片來源：Ahrens，p. 9，Fig. 1. 8)

大氣的自然組成成分 1. 不變成分 Composition of dry, aerosol-free air in volume percent. Three gases-nitrogen, oxygen, and argon--make up 99. 96 percent of the air.

Radiation and energy balance/unbalance 輻射能量平衡

Blackbody Radiation 黑體輻射 Any substance (solid, liquid or gas) emits radiation according to its absolute temperature (K = o. C + 273. 15). The efficiency at which radiation is emitted varies with the substance. However, at any temperature, there is an upper limit to how much radiation can be emitted. 物質都會自發出輻射(電磁波)，波長取決於物質的溫度而發射效 率取決於物質。在任何溫度下，發射出的輻射能量都有其上限。 A blackbody is a hypothetical body that: • Emits radiation at the maximum intensity possible for every wavelength. • Completely absorbs all incident radiation (hence the term “black”). 黑體為一假想物具有： 在每種波長下都有最大的發射效率 完全吸收入射的電磁波(無反射波所以看起來黑黑的故名之)

Planck’s Law普朗克定律 Describes the amount of radiation emitted by a blackbody at each wavelength as a function of temperature: Monochromatic irradiance 輻射通量密度 * refers to blackbody radiation. the wavelength in meters T is the absolute temperature in Kelvin (K) C 1 = 3. 74 10 -16 W m 2 C 2 = 1. 44 10 -2 m K

Stefan-Boltzmann Law司帝芬波茲曼定律 (the area under the curve) W m-2 = 5. 67 x 10 -8 W m-2 K-4 (the Stefan-Boltzmann constant) 一黑體表面單位面積在單位時間內輻 射出的總量與其溫度的4次方成正比 應用估算日面溫度 Wien Displacement Law韋恩定律 The wavelength of the peak in the spectral curve is given by 黑體的溫度與產生的電磁輻射中，能 量最大的波長之間呈現反比的關係

Scattering of Solar Radiation 太陽輻射之散射效應 Rayleigh scattering(瑞利散射): by particles (molecules in this case) much smaller than the wavelength of the radiation. Rayleigh scattering is very wavelength dependent such that the scattering coefficient (a measure of the efficiency of the scattering)

為何天空是藍的 (Rayleigh scattering) https: //www. youtube. com/watch? v=tw. Sg 2 zbjjn. A

Albedo 反照率

Insolation at the earth surface 地球表面接收之太陽輻射

Global distribution of insolation at the earth surface

Earth-atmosphere energy unbalance 地球大氣系統能量不平衡之緯度分佈

Earth-atmosphere energy balance diagram 地球大氣系統能量收支平衡

The way a greenhouse works 溫室效應如何形成 Short-wavelength radiation from the Sun passes through the glass roof and heats the ground. Some of the heat from the ground then warms the air in the greenhouse; the rest is re-radiated back as infrared radiation, which is then trapped by the glass roof, producing additional heating inside. The warmed air emits long-wavelength radiation which passes through the glass and escapes into the atmosphere. When a balance is reached, the incoming radiation equals the escaping radiation.

Variation of CO 2 concentration 二氧化碳濃度變化 Year ppmv CO 2 1860 1992 1998 2005 ~285 ~315 ~350 ~369 ~375

Figure 1 -5 p 8

SRES: Special Report on Emission Scenarios