Department of Atmospheric Sciences National Central University ChungLi

空氣汙染和全球暖化 王國英 Department of Atmospheric Sciences National Central University Chung-Li, Taiwan 環境研究中心 國立中央大學

7

8

9

2. 空氣汙染原理 Oxidation and transformation 1. • Several species in the troposphere are capable of absorbing solar radiation and hence initiating radicalchain oxidation. • Ozone is the photochemical precursor of the hydroxyal radicals: (R 1) O 3 + hν (R 2) O�('D) + H 2 O (R 3) O�('D) + M O�('D) + O 2 (λ ≤ 310 nm) O�H + OH O�+ M H 2 O is minor compared with M M= N 2 , O 2 環境研究中心 國立中央大學

• All ground state O atoms will generate ozone: (R 4) O�+ O 2 + M O� 3 + M • An important source for O�('D) production in the troposphere: NO 2 photolysis (R 5) NO 2 + hν 環境研究中心 O�+ NO (λ ≤ 400 nm) 國立中央大學

2 If nitrgen oxides are present in the troposphere (e. q polluted troposphere) (R 12) HO 2 + NO OH + NO 2 (R 13) CH 3 O 2 + NO CH 3 O + NO 2 + hν (R 14) CH 3 O + O 2 HCHO + HO 2 O + O 2 + M O + NO O 3 + M • (R 12) regenerate OH • (R 13), (R 14) yields formaldehyde (HCHO) • Formaldehyde then photolysed at λ< 338 nm to produce H and HCO (R 15) HCHO + hν + HCO (λ< 338 nm ) and both radicals re-enter the. HHO chain, via x (R 8) H + O 2 +M (R 16) HCO + O 2 環境研究中心 HO 2 + M CO + HO 2 for HCO 國立中央大學

Tropospheric ozone production • Photolysis of NO 2 is the only known way of producing ozone in the troposphere. OH + CO 2 H + O 2 + M HO 2 + NO OH + NO 2 + hν O O + O 2 + M O 3 + M net CO + 2 O 2 + hν CO 2 + O 3 + NO NOx must be present 環境研究中心 國立中央大學

• Below a certain critical value of the ratio NO/O 3 , ozone loss through the sequence HO 2 + O 3 OH + 2 O 2 CO + OH H + CO 2 H + O 2 + M net : CO + O 3 環境研究中心 HO 2 + M CO 2 + O 2 國立中央大學

Wrfchem 04/24~04/27 Temperature 環境研究中心 國立中央大學

1. The Air Pollution-Global Warming-Abrupt Climate Change Theory

5. Conclusion • Taiwan’s EPA contains very good real-time data for ambient air pollution measurements. • There are many interesting and important things can be done based on this data. • Since air pollution exerts big impact on human health, future researches focusing on the relationship between health and air pollution will be a hot topic for the years to come. 環境研究中心 國立中央大學