Development of analytical methods for the measurements of ozone and NOx fluxes and applications at a forest site

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K00520
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Environmental dynamic analysis
• Research Institution: Teikyo University of Science & Technology
• Principal Investigator: Wada Ryuichi 帝京科学大学, 生命環境学部, 准教授 (90566803)
• Co-Investigator(Kenkyū-buntansha): 松見 豊 名古屋大学, 宇宙地球環境研究所, 研究員 (30209605)
• Research Collaborator: TAKANASHI satoru ; MIYAMA takafumi ; TANI akira ; YONEMURA seiichiro ; UEYAMA masahito
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 窒素酸化物 / レーザー分光 / 森林 / フラックス

Outline of Final Research Achievements

We developed a direct measurement technique for NO2 using a laser-based instrument. We then used the instrument to observe NO2 flux in a forest at the foot of Mt. Fuji for 10 days during autumn 2016, and for 12 days during summer 2018. The NO2 flux during the nighttime was close to zero; however the NO2 flux during the daytime showed emissions from the forest. Generally, forest is thought to be NO2 sinks, because NO2 is absorbed by plants through their stomata and deposits on plant leaves. Our results indicate that it may be possible that there is another mechanism for NO2 emissions from a forest.

Free Research Field

大気環境科学

Academic Significance and Societal Importance of the Research Achievements

大気環境に影響を及ぼす反応性窒素ガスの発生・沈着の時間変動とその要因の解明が遅れている．森林生態系は反応性窒素ガスの発生・沈着の時間変動の要因の一つと考えられるものの森林内部空間における窒素酸化物の動態に関する研究は少ない．これは森林生態系における反応性窒素ガスの濃度を高い時間分解能で正確に計測できる分析装置がほとんどないことが一因である．いままで難しかった渦相関法による窒素酸化物フラックス計測手法を確立したことで，森林内部の窒素酸化物の放出・吸収量の日変化・季節変化を，定量的に解明し、その変動要因を明らかにすることが期待できる．