Observations of new particle formation and size distributions at two different heights and surroundings in subarctic area in northern Finland
Observations of new particle formation and size distributions at two different heights and surroundings in subarctic area in northern Finland
复制标题
芬兰北部亚北极地区两个不同高度和环境下新颗粒形成和尺寸分布的观测
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
Y. Viisanen
中科院分区：
文献类型：
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作者：
M. Komppula;H. Lihavainen;J. Hatakka;J. Paatero;P. Aalto;M. Kulmala;Y. Viisanen
[1]在芬兰北部的亚北极地区进行了连续两年的气溶胶颗粒数大小分布测量。在两个不同的高度（海拔340米和560米）和周围环境（森林内部和农田顶部）进行了测量，以找出局地尺度条件对新颗粒形成和生长以及气溶胶颗粒大小分布的影响。测量的气溶胶粒径范围为7 ~ 500 nm。2001年平均总浓度在高海拔地区为700 cm−3，在低海拔地区为870 cm−3。日平均值在40至3500厘米−3之间变化。两站总浓度的季节变化基本一致，春、夏季高，冬季低。此外，还比较了模态浓度。两个地点的总颗粒浓度日变化相似。在测量期间，总共记录了65个新的粒子形成事件。最多的事件发生在4月和5月。粒子形成事件开始于0825和1550之间（UTC加2小时），计算出的1纳米粒子形成（成核）的开始时间在0450和1420之间变化。颗粒的生长速率为1.4 ~ 8.2 nm h−1,7 nm颗粒的形成速率为0.06 ~ 0.40 nm cm−3 s−1。两个站点形成事件的开始时间最大相差30 min，不能用风向和风速来解释。时差的一个可能解释是由湍流引起的气团垂直运动。太阳辐射被观察到是粒子形成所需的一个关键因素。形成日风向多在西、北之间，表示极气团或北极气团。
[1] Two years of continuous aerosol particle number size distribution measurements have been carried out in a subarctic area in northern Finland. Measurements have been made at two different heights (340 m and 560 m above sea level) and surroundings (inside a forest and at the top of a fjeld) to find out the effects of local-scale conditions on new particle formation and growth as well as on the size distribution of aerosol particles. Measured aerosol particle size range was 7–500 nm. Average total number concentration in the year 2001 was 700 cm−3 at the higher and 870 cm−3 at the lower site. One-day averages varied between 40 and 3500 cm−3. Seasonal variation of total concentration was observed to be similar at both stations, high values in spring and summer and low values in winter. Also, modal concentrations were compared. Diurnal variation of total particle concentration was similar at both sites. In total, 65 new particle formation events were recorded during the measuring period. The largest number of events occurred in April and May. Particle formation events started between 0825 and 1550 (UTC plus 2 hours), and the calculated starting times of 1 nm particle formation (nucleation) varied between 0450 and 1420. The particle growth rate was found to be 1.4–8.2 nm h−1, and the formation rate of 7 nm particles varied from 0.06 to 0.40 particles cm−3 s−1. Starting times of the formation events at the two stations had maximum difference of 30 min, and it could not be explained by wind direction and speed. One possible explanation for the time difference is vertical movement of air masses caused by turbulence. Solar radiation was observed to be one key factor needed for particle formation. Wind direction was mostly between west and north on formation days, indicating polar or arctic air masses.
影响因子：
20.8
作者：
DOCKERY, DW;POPE, CA
通讯作者：
POPE, CA