Aerosol composition at a coastal monitoring site in Hong Kong--initial results

ＡｅｒｏｓｏｌｃｏｍｐｏｓｉｔｉｏｎａｔａｃｏａｓｔａｌｍｏｎｉｔｏｒｉｎｇｓｉｔｅｉｎＨｏｎｇＫｏｎｇ—ｉｎｉｔｉａｌｒｅｓｕｌｔｓＫ．Ｓ．Ｌａｍ，Ｌ．Ｙ．Ｃｈａｎ，Ｚ．Ｌ．ＣｈｅｎｇＤｅｐａｒｔｍｅｎｔｏｆＣｉｖｉｌａｎｄＳｔｒｕｃｔｕｒａｌＥｎ...     

Aerosol optical properties derived from imultaneoussunphotometer and aureolemeter measurements in Lhasa

In order to obtain some aerosol properties in Tibetan Plateau atmosphere, simultaneous measurements of aerosols by use of a sunphotometer and an aureolementer were performed in the summer of 1998 in Lhasa(29.65°N, 91.13°E). Optical depth, volume size distribution and phase-function of aerosols were obtained from the measurements. Religious activities can have an effect on optical depth in Lhasa. The daily average aerosol optical depth(λ相似文献   

Aerosol optical properties derived from simultaneous sunphotometer and aureolemeter measurements in Lhasa

ＩｎｔｒｏｄｕｃｔｉｏｎＡｅｒｏｓｏｌｓｈａｖｅｔｈｅｐｏｔｅｎｔｉａｌｔｏｃｈａｎｇｅｔｈｅｇｌｏｂａｌｃｌｉｍａｔｅｂｅｃａｕｓｅｏｆｔｈｅｉｒｄｉｒｅｃｔｒａｄｉａｔｉｖｅｅｆｆｅｃｔｓａｎｄｔｈｅｉｒｉｎｄｉｒｅｃｔｅｆｆｅｃｔｓａｓｃｌｏｕｄｃｏｎｄｅｎｓａｔｉｏｎｎｕｃｌｅｉ.Ａｅｒｏｓｏｌｓａｒｅａｌｓｏｉｍｐｏｒｔａｎｔｃｏｍｐｏｎｅｎｔｓｉｎｂｉｏｇｅｏｃｈｅｍｉｃａｌｃｙｃｌｅｓａｎｄｉｎｈｅｔｅｒｏｇｅｎｅｏｕｓｃｈｅｍｉｓｔｒｙ ,ｗｈｉｃｈｃａｎａｆｆｅｃｔｔｒａｃｅ ｇａ…     

Aerosol formation and growth in atmospheric organic/NOχ systems—I. Outdoor smog chamber studies of C7- and C8-hydrocarbons

Outdoor smog chamber experiments have been performed to determine the aerosol-forming potential of selected C₇- and C₈-hydrocarbons in sunlight-irradiated hydrocarbon-NO_χ mixtures. Measured aerosol size distributions were used to determine the rates of gas-to-particle conversion and to study the effects of the addition of SO₂ and/or NH₃ on aerosol formation and growth. The average aerosol yields by mass for the hydrocarbons studied were (the range of measured values for methylcyclohexane and 1-octene are in parentheses):

• •methylcyclohexane 9.2% (0.12–18.8);
• •1-octene 4.2% (0.17–6.9);
• •toluene 18.6%;
• •n-octane <0.001%.

The average yields are accompanied by large standard deviations (see Table 3) and depended strongly on the conditions, particularly the hydrocarbon to NO_χ initial concentration ratio. Addition of SO₂ to the organic/NO_χ systems led to an early nucleation burst and subsequent rapid growth of the newly formed aerosol. In the presence of NH₃, the gas-to-particle conversion rate of the organic/NO_χ system was enhanced perhaps due to the formation of NH₄NO₃ or the reaction of NH₃ with carboxylic acids. Sustained particle formation was observed when both SO₂ and NH₃ were present, presumably as a result of (NH₄)₂SO₄ formation. We have estimated the complexity of the 1-octene aerosol and identified 5-propyl furanone as a component of the aerosol.