Tower- and drone-based BVOC observations in a suburban Tokyo forest: methodological insights and MEGAN comparison

IF 5.7 1区地球科学 Q1 ENVIRONMENTAL SCIENCES

Atmospheric Chemistry and Physics Pub Date : 2026-09-04 DOI:10.5194/acp-26-12521-2026

Yujiro Ichikawa,Katsuhito Yoshida,Shinichi Yonemochi,Kentaro Takagi,Atsuyuki Sorimachi,Kazuhide Matsuda,Toshimasa Ohara

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引用次数: 0

Abstract

Abstract. Biogenic volatile organic compounds (BVOCs) substantially influence regional photochemical air pollution, climate, and the carbon cycle. However, observational constraints on BVOC emissions from urban or suburban forests in Asian megacity regions under humid subtropical climates remain limited. In this study, we conducted multi-year intermittent, multi-height BVOC observations at a 30 m flux tower in a suburban Tokyo forest dominated by Quercus serrata. Spatial variability was examined by combining tower measurements with supplemental drone-based sampling. The measurements were compared with estimates from the Model of Emissions of Gases and Aerosols from Nature (MEGAN). Isoprene volume mixing ratios increased during the warm-season observations from May to October, accounting for over 90 % of the measured BVOC composition during peak summer, while monoterpenes remained low with weak vertical gradients. Isoprene exhibited distinct vertical volume mixing ratio gradients peaking within the canopy, with the daily average emission fluxes ranging from −0.05 to 15.30 mgm-2h-1. Drone-based measurements indicated horizontal variability in isoprene volume mixing ratios of approximately 10 %–30 % within 30 m of the tower. Flux estimates derived from tower and drone measurements differed by approximately 30 %, suggesting that small-scale spatial heterogeneity and height differences can affect gradient-based flux estimates. MEGAN generally overestimated the observed fluxes, particularly during the warm-season observations. These results demonstrate the potential of combining tower-based vertical profiling with supplemental drone-based horizontal sampling to evaluate BVOC fluxes and their spatial representativeness. Although the intermittent sampling design limits comprehensive seasonal and interannual interpretations, this study provides methodological insights for future tower- and drone-based BVOC observations and emission model evaluation based on canopy-scale measurements.

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东京郊区森林中基于塔和无人机的BVOC观测：方法学见解和MEGAN比较

摘要。生物源性挥发性有机化合物（BVOCs）对区域光化学空气污染、气候和碳循环产生重大影响。然而，在潮湿的亚热带气候下，亚洲特大城市地区的城市或郊区森林对BVOC排放的观测限制仍然有限。在这项研究中，我们在东京郊区以锯齿栎为主的森林中，在一个30米通量塔上进行了多年间断、多高度的BVOC观测。通过结合塔测量和补充无人机采样来检查空间变异性。测量结果与自然界气体和气溶胶排放模型（MEGAN）的估计结果进行了比较。5 ~ 10月暖季观测期间，异戊二烯体积混合比增加，占夏季峰值BVOC组成的90%以上，而单萜保持较低水平，垂直梯度较弱。异戊二烯表现出明显的垂直体积混合比梯度，在冠层内达到峰值，日平均排放通量在−0.05 ~ 15.30 mg -2h-1之间。基于无人机的测量表明，在塔30米范围内，异戊二烯体积混合比的水平变化约为10% - 30%。塔和无人机测量得出的通量估算值相差约30%，这表明小尺度空间异质性和高度差异会影响基于梯度的通量估算。梅根总体上高估了观测到的通量，特别是在暖季观测期间。这些结果表明，将基于塔的垂直剖面与补充的基于无人机的水平采样相结合，可以评估BVOC通量及其空间代表性。尽管间歇性采样设计限制了全面的季节和年际解释，但本研究为未来基于塔式和无人机的BVOC观测和基于冠层尺度测量的排放模型评估提供了方法见解。

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来源期刊

Atmospheric Chemistry and Physics 地学-气象与大气科学

CiteScore

10.70

自引率

20.60%

发文量

702

审稿时长

6 months

期刊介绍： Atmospheric Chemistry and Physics (ACP) is a not-for-profit international scientific journal dedicated to the publication and public discussion of high-quality studies investigating the Earth''s atmosphere and the underlying chemical and physical processes. It covers the altitude range from the land and ocean surface up to the turbopause, including the troposphere, stratosphere, and mesosphere. The main subject areas comprise atmospheric modelling, field measurements, remote sensing, and laboratory studies of gases, aerosols, clouds and precipitation, isotopes, radiation, dynamics, biosphere interactions, and hydrosphere interactions. The journal scope is focused on studies with general implications for atmospheric science rather than investigations that are primarily of local or technical interest.