Observations of particle formation and growth in a mountainous forest region in central Europe
Observations of particle formation and growth in a mountainous forest region in central Europe
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中欧山区森林地区颗粒形成和生长的观察
DOI：
10.1029/2004jd005346
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发表时间：
2004
影响因子：
--
通讯作者：
O. Klemm
中科院分区：
文献类型：
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作者：
A. Held;A. Nowak;W. Birmili;A. Wiedensohler;R. Forkel;O. Klemm
[1]2001年和2002年夏季，在德国东北部巴伐利亚州“FichtelgeBirge”山脉的一个森林生态系统研究地点观察到了颗粒的形成和生长。通过详细分析亚微米粒子尺寸分布的时间演变确定的大气成核事件，在超细粒子浓度和气象参数方面与非事件日有很大不同。通过3-60 nm颗粒组分的几何平均直径发展来量化颗粒直径增长速率，范围从2.2nmh−1到5.7nmhα1。虽然H_2SO_4浓度通常不到观察到的增长速率的10%，但颗粒增长的很大一部分可以通过α-Pinene氧化产生的有机蒸汽的冷凝来解释。在几天内，H_2SO_4和α-蒎烯氧化产物的共缩合足以充分解释观察到的生长动力学。虽然树木植被排放的BVOC可能有助于颗粒物的形成，但森林也是颗粒物的有效汇。这反映在向森林中的颗粒沉积相对于排放的优势上，最强的沉积通量发生在颗粒形成事件期间。
[1] In the summers of 2001 and 2002, particle formation and growth were observed at a forest ecosystem research site in the “Fichtelgebirge” mountain range in NE Bavaria, Germany. Atmospheric nucleation events, identified through detailed analysis of the time evolution of submicron particle size distributions, differed considerably from nonevent days with respect to ultrafine particle concentrations and meteorological parameters. Particle diameter growth rates, as quantified through the geometric mean diameter development of the 3–60 nm particle fraction, ranged from 2.2 to 5.7 nm h−1. While H2SO4 concentrations typically explained less than 10% of the observed growth rates, a significant fraction of particle growth may be explained through condensation of organic vapors from α-pinene oxidation. On several days, cocondensation of H2SO4 and α-pinene oxidation products was sufficient to fully explain the observed growth dynamics. While BVOC emissions from the tree vegetation may contribute to particle formation, the forest also acts as an effective sink for particles. This is reflected in the dominance of particle deposition to the forest over emission, with the strongest deposition fluxes occurring during particle formation events.