Measurements of new particle formation and ultrafine particle growth rates at a clean continental site
Measurements of new particle formation and ultrafine particle growth rates at a clean continental site
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DOI：
10.1029/96jd03656
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发表时间：
1997-02
影响因子：
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通讯作者：
R. Weber;James J. Marti;P. Mcmurry;F. Eisele;D. Tanner;A. Jefferson
中科院分区：
文献类型：
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作者：
R. Weber;James J. Marti;P. Mcmurry;F. Eisele;D. Tanner;A. Jefferson
在科罗拉多的爱达荷州山，一个偏远的大陆站点同时测量气溶胶粒子和它们预期的气相前体。这项研究使用的设备和技术与夏威夷莫纳罗亚天文台早期研究中使用的设备和技术相似[韦伯等人，1995年]。新的颗粒形成，确定存在的超细颗粒（标称3至4纳米直径），通常观察到在下坡（西风）的空气，并与高硫酸（H2SO4）浓度，低相对湿度和低颗粒表面积浓度。数据表明H2SO4是主要的成核前体物质，典型的日间浓度在106至107分子cm−3之间。颗粒生产观察到在H2SO4浓度远低于预测值的二元成核H2O和H2SO4，这表明另一种参与。颗粒生长速率估计的数据与两个独立的方法，在这两种情况下是10.5至10倍，可以解释的H2SO4和其相关的水的冷凝。这表明除了H2SO4之外的物质也对超细颗粒生长做出了很大贡献。最后，计算出的稳态H2SO4浓度被认为是在良好的协议与测量值，如果气溶胶表面上的H2SO4的质量调节系数被假定为等于10.1。
Simultaneous measurements of aerosol particles and their expected gas phase precursors were made at Idaho Hill, Colorado, a remote continental site. This study used apparatus and techniques similar to those employed in an earlier study at the Mauna Loa Observatory, Hawaii [Weber et al., 1995]. New particle formation, identified by the presence of ultrafine particles (nominally 3 to 4 nm diameter), was commonly observed in downslope (westerly) air and was correlated with high sulfuric acid (H2SO4) concentrations, low relative humidity and low particle surface area concentrations. The data point to H2SO4 as a principle nucleation precursor species with typical daytime concentrations between 106 and 107 molecules cm−3. Particle production was observed at H2SO4 concentrations that are well below predicted values for binary nucleation of H2O and H2SO4, suggesting that another species participated. Particle growth rates were estimated from the data with two independent approaches and in both cases were ∼5 to 10 times higher than can be explained by condensation of H2SO4 and its associated water. This suggests that species in addition to H2S04 were also making large contributions to ultrafine particle growth. Finally, calculated steady-state H2SO4 concentrations were found to be in good agreement with measured values if the mass accommodation coefficient for H2SO4 on aerosol surfaces was assumed equal to ∼1.