Open AccessDiurnal variation of ionic aerosol species and water‐soluble gas concentrations at a high‐elevation site in the Japanese Alps
Author(s) -
Kido Mizuka,
Osada Kazuo,
Matsunaga Katsuji,
Iwasaka Yasunobu
Publication year - 2001
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2000jd900775
Subject(s) - aerosol , sea salt , troposphere , sulfate , atmospheric sciences , diurnal temperature variation , environmental science , daytime , atmosphere (unit) , climatology , environmental chemistry , chemistry , geology , meteorology , geography , organic chemistry
Size‐separated atmospheric aerosol particles, acidic gases, and ammonia were collected during the daytime and nighttime at Murododaira (36.6°N, 137.6°E, 2450 m above sea level), Mount Tateyama, Japan in early winter. Non‐sea‐salt (nss) SO 4 2− in fine fractions (<2.1 μm in diameter) was the most dominant ionic constituent and occupied 44% on average of the ionic mass concentration other than H + . Concentration levels of aerosol ions and water‐soluble gases were higher during the day and lower at night. Concentrations of the nighttime aerosol particles and gases (except for SO 2 ) were similar to free‐tropospheric background levels at various sites of northern midlatitudes in the literature, suggesting that nighttime data at Murododaira were representative of free‐tropospheric conditions. High concentration levels of SO 2 at Murododaira were close to those over the northwest Pacific Rim region during the winter season. Molar ratios of nssSO 4 2− /SO 2 can be explained by the transport time from the Asian continent, suggesting that a significant source of fine nssSO 4 2− aerosols at Murododaira in early winter could be due to the oxidation of anthropogenic SO 2 derived from the Asian continent. The equivalent ratios of nssSO 4 2− to NH 4 + in fine particles were close to 0.5 under westerly wind conditions, suggesting the existence of half‐neutralized sulfate on average.