Scholarlink

<p>Tropospheric ozone (O<sub>3</sub>) is an air pollutant and greenhouse gas and is still a problem in East Asia. O<sub>3</sub> is formed via secondary photochemistry from nitrogen oxide (NO<sub>x</sub>) and volatile organic compound (VOC) precursors. Because of the increase in anthropogenic emissions globally, changes in O<sub>3</sub> concentration over the Northern Hemisphere have been a concern. In this study, using measurements at three remote sites conducted by the Japan Meteorological Agency (JMA), the 30-year (1990s to 2020) long-term trend of background O<sub>3</sub> concentration was analyzed. The results of the fitted curve revealed that background O<sub>3</sub> concentration has changed by within ±0.3 ppbv/year over 30 years. The increasing trend at Ryori (39.03°N, 141.82°E) peaked in 2009 and then decreased, agreeing well with other reports in the mid-latitude zone (40°N-55°N). In contrast, the present study revealed continuous decreasing trends at Minamitorishima (24.28°N, 153.98°E) and Yonagunijima (24.47°N, 123.02°E) at lower latitudes. In addition, the analysis for 2020 clarified that the frequency density shifted to a lower O<sub>3</sub> concentration compared with the dataset for the 1990s to 2019 at all three remote sites in Japan. This suggested that the emission reduction resulting from the COVID-19 pandemic could be a factor causing the decreasing background O<sub>3</sub> concentration.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Long-Term 30-Year Variation (1990s-2020) of Background Tropospheric Ozone Concentration at Japanese Remote Stations

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2025年1月1日

查看全文
  • Syuichi Itahashi

摘要

Tropospheric ozone (O3) is an air pollutant and greenhouse gas and is still a problem in East Asia. O3 is formed via secondary photochemistry from nitrogen oxide (NOx) and volatile organic compound (VOC) precursors. Because of the increase in anthropogenic emissions globally, changes in O3 concentration over the Northern Hemisphere have been a concern. In this study, using measurements at three remote sites conducted by the Japan Meteorological Agency (JMA), the 30-year (1990s to 2020) long-term trend of background O3 concentration was analyzed. The results of the fitted curve revealed that background O3 concentration has changed by within ±0.3 ppbv/year over 30 years. The increasing trend at Ryori (39.03°N, 141.82°E) peaked in 2009 and then decreased, agreeing well with other reports in the mid-latitude zone (40°N-55°N). In contrast, the present study revealed continuous decreasing trends at Minamitorishima (24.28°N, 153.98°E) and Yonagunijima (24.47°N, 123.02°E) at lower latitudes. In addition, the analysis for 2020 clarified that the frequency density shifted to a lower O3 concentration compared with the dataset for the 1990s to 2019 at all three remote sites in Japan. This suggested that the emission reduction resulting from the COVID-19 pandemic could be a factor causing the decreasing background O3 concentration.