動的な凝縮成長過程におけるエアロゾルの吸湿性を追跡する新システムを開発(Research group from School of Environment develops new system to track aerosol hygroscopicity during dynamic condensational growth)

2026-08-12 清華大学

超微小粒子(粒径100nm未満)は大気中の個数濃度を支配し、健康や気候に大きな影響を及ぼす一方、凝縮成長に関与する化学成分の長期変動は十分把握されていなかった。清華大学環境学院の研究グループは、走査型移動度粒径測定器(SMPS)とHTDMAを統合した「SMASH」を開発。6分という高時間分解能で、粒子径と吸湿性を同期追跡できる。北京で約30時間にわたり観測した結果、成長・収縮過程や単峰・二峰の成長を捉え、吸湿性パラメータκの変化から凝縮成分の特性や成長機構を識別できた。低コストで保守も容易なため、長期・広域観測への展開が期待される。さらにTD-CIMSやCPMAとの統合により、分子組成・密度を含む多面的な測定や大気化学モデルへの活用も可能となる。

動的な凝縮成長過程におけるエアロゾルの吸湿性を追跡する新システムを開発(Research group from School of Environment develops new system to track aerosol hygroscopicity during dynamic condensational growth)
Figure 1. Exemplary condensational growth case captured by the system developed in this study, which occurred in Beijing on July 17 and 18, 2025. (a) Modal diameter, (b)k , and (c)kc or kv during the growth events. The “I-” and “II-” represents growth case I and II, while “GE” and “SE” represent growing episode x and shrinkage episode x, respectively. Shaded areas in (b) and (c) represent uncertainties of and kc.

<関連情報>

大気エアロゾルの長期的な多峰性凝縮成長を、エアロゾルサイズと吸湿性の同期モニター(SMASH)を用いて特徴付ける Characterizing Long-Term Multimodal Condensational Growth of Atmospheric Aerosols with the Synchronous Monitor of Aerosol Size and Hygroscopicity (SMASH)

Chun Xiong;Guangjie Zheng;Qiang Zhang;Yuyang Li;Dongbin Wang;Zhibin Wang;Jingkun Jiang;Kebin He
Environmental Science & Technology  Published:June 25, 2026
DOI:https://doi.org/10.1021/acs.est.6c00847

Abstract

Ultrafine particles (diameters <100 nm) dominate atmospheric particle number concentrations, exerting substantial health and climatic impacts. Condensational growth significantly modifies their size and chemical composition, yet the long-term dominant condensing species remain poorly characterized, largely due to the lack of suitable instruments. Here, we developed the Synchronous Monitor of Aerosol Size and Hygroscopicity (SMASH) for condensing species characterization, integrating a rapid modal diameter identification strategy and the data transmissions between size distribution and size-resolved hygroscopicity measurements. This system thereby enables high-time-resolution (6 min) tracing of growing modal diameter and concurrent hygroscopicity measurements. The hygroscopicity parameter of condensing species, κc, can be subsequently derived, which is indicative of its chemical compositions. This system also enabled characterization of multimodal simultaneous growth events, which yield unique insights into the size-dependence of condensations. The measured κc exhibits high sensitivity to condensing species variations, offering a potential standardized method for growth episode classification and growth rate calculations. Moreover, the highly time-resolved measurements can discern the occurrence of nonideal mixing and thereby constraining associated uncertainties. Considering the dynamic mode-tracking capability, the high time resolution, low cost, and easy maintenance, this system is a promising new tool for large-scale long-term measurements to investigate general characteristics of condensing species.

1902環境測定
ad
ad
Follow
ad
タイトルとURLをコピーしました