[U24-P05] Impact of air quality caused by the COVID-19 lockdown in China, observed at downwind of Japan’s mountainous area.
キーワード：COVID-19, Lockdown, Air pollution, Long-range transport, Rime ice, Free trophosphere
Covid-19 lockdown have led to a drastic improvements of air quality in many cities all over the world. The Himalayas were visible from the city areas in India, which have not been seen for 30 years due to the air pollution. In China, during the Olympic period in 2008, temporal improvement of air quality was recognized in Beijing. However, this is the first time since improvements of air quality in many cities in China. In this research, in order to clarify whether the improvement of air quality was observed or not caused by COVID-19 lockdown in Kyushu mountainous region, Japan, where the downwind of these are highly are polluted cities in main land China, we observed the NO3-, nssSO42-, T-Hg, and microplastics in the rime ice. We collected rime ice from 1,500 to 1,700 m a.s.l.
NO3-, nssSO42- Hg concentration and number of microplastics in rime ice sampled in mountainous area of Kyushu in Japan, are drastically decreased after lockdown which were conducted in January 23 and 24 in Hubei region, China. NO3-, nssSO42- and T-Hg in rime ice collected on the 18th January, which is before lockdown, were 12.3 mg/L 6.02 mg/L, and 27.7 ng/L, respectively. Number of microplastics was 56 × 103 N/L. On the other hand, the rime ice collected on 18 February after lockdown of Hubei region, China, NO3-, nssSO42- and T-Hg concentration were 1.61 mg/L, 5.54 mg/L and 5.71 ng/L, respectively. Also, the number of microplastics were 22 × 103 N/L.
Authors have been collected rime ice since 1990s and these NO3- and nssSO42- concentrations observed in 18 February were lower than 1990s level.
NO3-, nssSO42- Hg concentration and number of microplastics in rime ice sampled in mountainous area of Kyushu in Japan, are drastically decreased after lockdown which were conducted in January 23 and 24 in Hubei region, China. NO3-, nssSO42- and T-Hg in rime ice collected on the 18th January, which is before lockdown, were 12.3 mg/L 6.02 mg/L, and 27.7 ng/L, respectively. Number of microplastics was 56 × 103 N/L. On the other hand, the rime ice collected on 18 February after lockdown of Hubei region, China, NO3-, nssSO42- and T-Hg concentration were 1.61 mg/L, 5.54 mg/L and 5.71 ng/L, respectively. Also, the number of microplastics were 22 × 103 N/L.
Authors have been collected rime ice since 1990s and these NO3- and nssSO42- concentrations observed in 18 February were lower than 1990s level.