Dry Deposition of PM2.5 Nitrate in a Forest according to Vertical Profile Measurements
The atmospheric nitrogen compounds can serve as a nutrient; however, its excess deposition has harmful effects on terrestrial ecosystems due to acidification and eutrophication. There are still large uncertainties concerning the dry deposition process of PM2.5 nitrate in forests, even though this pr...
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| Format: | Article |
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Springer
2020-12-01
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| Series: | Asian Journal of Atmospheric Environment |
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| Online Access: | http://asianjae.org/_common/do.php?a=current&b=11&bidx=2308&aidx=27003 |
| _version_ | 1797717416627666944 |
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| author | Mao Xu Kazuhide Matsuda |
| author_facet | Mao Xu Kazuhide Matsuda |
| author_sort | Mao Xu |
| collection | DOAJ |
| description | The atmospheric nitrogen compounds can serve as a nutrient; however, its excess deposition has harmful effects on terrestrial ecosystems due to acidification and eutrophication. There are still large uncertainties concerning the dry deposition process of PM2.5 nitrate in forests, even though this process affects the accuracy of chemical transport model simulations. To better understand this process, we conducted vertical profile measurements of inorganic ions in PM2.5 and SO2 above and within a forest canopy in the Field Museum Tamakyuryo site in suburban Tokyo with a particular focus on the processes observed under both daytime and nighttime and both leafy and leafless conditions. We performed two observations during leafy periods (July 21-August 1, 2015, and September 27-October 11, 2016) and one observation during a leafless period (February 23-29, 2016). To obtain daytime and nighttime vertical profiles, we set filter holders at 4 or 5 heights on an observation tower in the forest and changed the filters for each daytime and nighttime. For the PM2.5, the vertical gradients of NO3- concentration were larger than those of SO42- during both the daytime and nighttime for all observational periods, particularly during the leafy periods. In addition, the decreasing rate of NO3- in the PM2.5 within the canopy was larger than that of SO2 for some observational periods. In the daytime, the air temperature was higher near the canopy surface during the leafy period and near the ground surface during the leafless period. As also suggested by past studies, the large gradients of NO3- in the PM2.5 during the leafy period were likely caused by the volatilization of NH4NO3 near the deposition surfaces due to the higher temperature in the daytime and the lower concentration of HNO3 caused by its fast removal during both the daytime and nighttime. |
| first_indexed | 2024-03-12T08:36:01Z |
| format | Article |
| id | doaj.art-9971fb735eb74f2f99261028568cee23 |
| institution | Directory Open Access Journal |
| issn | 1976-6912 2287-1160 |
| language | English |
| last_indexed | 2024-03-12T08:36:01Z |
| publishDate | 2020-12-01 |
| publisher | Springer |
| record_format | Article |
| series | Asian Journal of Atmospheric Environment |
| spelling | doaj.art-9971fb735eb74f2f99261028568cee232023-09-02T17:16:54ZengSpringerAsian Journal of Atmospheric Environment1976-69122287-11602020-12-0114436737710.5572/ajae.2020.14.4.367Dry Deposition of PM2.5 Nitrate in a Forest according to Vertical Profile MeasurementsMao Xu0Kazuhide Matsuda1United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, JapanUnited Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, JapanThe atmospheric nitrogen compounds can serve as a nutrient; however, its excess deposition has harmful effects on terrestrial ecosystems due to acidification and eutrophication. There are still large uncertainties concerning the dry deposition process of PM2.5 nitrate in forests, even though this process affects the accuracy of chemical transport model simulations. To better understand this process, we conducted vertical profile measurements of inorganic ions in PM2.5 and SO2 above and within a forest canopy in the Field Museum Tamakyuryo site in suburban Tokyo with a particular focus on the processes observed under both daytime and nighttime and both leafy and leafless conditions. We performed two observations during leafy periods (July 21-August 1, 2015, and September 27-October 11, 2016) and one observation during a leafless period (February 23-29, 2016). To obtain daytime and nighttime vertical profiles, we set filter holders at 4 or 5 heights on an observation tower in the forest and changed the filters for each daytime and nighttime. For the PM2.5, the vertical gradients of NO3- concentration were larger than those of SO42- during both the daytime and nighttime for all observational periods, particularly during the leafy periods. In addition, the decreasing rate of NO3- in the PM2.5 within the canopy was larger than that of SO2 for some observational periods. In the daytime, the air temperature was higher near the canopy surface during the leafy period and near the ground surface during the leafless period. As also suggested by past studies, the large gradients of NO3- in the PM2.5 during the leafy period were likely caused by the volatilization of NH4NO3 near the deposition surfaces due to the higher temperature in the daytime and the lower concentration of HNO3 caused by its fast removal during both the daytime and nighttime.http://asianjae.org/_common/do.php?a=current&b=11&bidx=2308&aidx=27003air-surface exchangegradientsemi-volatile aerosolsammonium nitrateleaf area |
| spellingShingle | Mao Xu Kazuhide Matsuda Dry Deposition of PM2.5 Nitrate in a Forest according to Vertical Profile Measurements Asian Journal of Atmospheric Environment air-surface exchange gradient semi-volatile aerosols ammonium nitrate leaf area |
| title | Dry Deposition of PM2.5 Nitrate in a Forest according to Vertical Profile Measurements |
| title_full | Dry Deposition of PM2.5 Nitrate in a Forest according to Vertical Profile Measurements |
| title_fullStr | Dry Deposition of PM2.5 Nitrate in a Forest according to Vertical Profile Measurements |
| title_full_unstemmed | Dry Deposition of PM2.5 Nitrate in a Forest according to Vertical Profile Measurements |
| title_short | Dry Deposition of PM2.5 Nitrate in a Forest according to Vertical Profile Measurements |
| title_sort | dry deposition of pm2 5 nitrate in a forest according to vertical profile measurements |
| topic | air-surface exchange gradient semi-volatile aerosols ammonium nitrate leaf area |
| url | http://asianjae.org/_common/do.php?a=current&b=11&bidx=2308&aidx=27003 |
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