• Journal of Korean Society of Environmental Engineers
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• v.29 no.1
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• pp.113-125
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• 2007

To know the differences in ionic compositions in rain and snow as well as snow influence on the chemical characteristics of winter precipitation, precipitation samples were collected by the wet-only automatic precipitation sample, in winter(November-February) in the Iksan located in the northwest of Chonbuk from 1995 to 2000. The samples were analyzed for concentrations of water-soluble ion species, in addition to pH and electrical conductivity. The mean pH of winter precipitation was 4.72. According to the type of winter precipitation, the mean pH of rain was 4.67 and lower than 5.05 in snow. The frequencies of pH below 5.0 in rain were about 73%, while those in snow were about 30%. Snow contained 3 times higher concentrations of sea salt ion components originated from seawater than did rain in winter, mainly $Cl^-,\;Na^+$, and $Mg^{2+}$. Neglecting sea salt ion components, $nss-SO_4^{2-}$ and $NO_3^-$ were important anions and $NH_4^+$ and $nss-Ca^{2+}$ were important cations in both of rain and snow. Concentrations of $nss-SO_4^{2-}$ was 1.3 times higher in rain than in snow, while those of $nss-Ca^{2+}$ and $NO_3^-$ were 1.5 and 1.3 times higher in snow, respectively. The mean equivalent concentration ratio of $nss-SO_4^{2-}/NO_3^-$ in winter precipitation were 2.4, which implied that the relative contribution of sulfuric and nitric acids to the precipitation acidity was 71% and 29%, respectively. The ratio in rain was 2.7 and higher than 1.5 in snow. These results suggest that the difference of $NO_3^-$ in rain and snow could be due to the more effective scavenging of $HNO_3$ vapor than particulate sulfate or nitrate by snow. The lower ratio in snow than rain is consistent with the measurement results of foreign other investigators and with scavenging theory of atmospheric aerosols. Although substantial $nss-SO_4^{2-}$ and $NO_3^-$ were observed in both of rain and snow, the corresponding presence of $NH_4^+,\;nss-Ca^{2+},\;nss-K^+$ suggested the significant neutralization of rain and snow. Differences in chemical composition of non-sea salt ions and neutralizing rapacity of $NH_4^+,\;nss-Ca^{2+}$, and $nss-K^+$ between rain and snow could explain the acidity difference of rain and snow. Snow affected that winter precipitation could be less acidic due to its higher neutralizing rapacity.

• Ocean and Polar Research
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• v.44 no.4
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• pp.297-310
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• 2022

To understand the chemical composition of aerosols in the Cheju-Korea Straits and their contribution to the ocean by deposition, aerosol samples were collected on board R/V Eardo from November 1997 to May 1999. The average concentrations of Al, NO₃^-, non-sea-salt (nss)-SO₄^2-, and NH₄⁺ in aerosols were 2.19, 5.59, 6.16 and 2.08 ㎍ m^-3, respectively. The Al concentration in the high yellow dust period was about 100 times higher than that in the non-yellow dust period. The concentration ratio of NO₃^-/nss-SO₄^2- ranged between 0.47 and 1.5, indicating that the aerosols in the Cheju-Korea Straits are under the effects of NO_x and SO_x emitted from China, Korea and Japan. The equivalent concentration ratio of [NH₄⁺]/[nss-SO₄^2-+ NO₃^-] with the average of 0.58±0.29 indicates that nss-SO₄^2- and NO₃^- are not neutralized by NH₄⁺. A high activity concentration of ²¹⁰Pb with 1.13-1.23 mBq m^-3 was observed during the high yellow dust period, indicating that ²¹⁰Pb is easily adsorbed in the yellow dust originating from the continent of Asia. The distribution of ⁷Be and NH₄⁺ concentrations showed a strong negative linear correlation during the low yellow dust period, April 1998. The total mineral dust flux in the Cheju-Korea Straits was estimated to be 1.21×10⁶ tons yr^-1, accounting for about 12% of the annual sediment discharge via the Nakdong River. The combined annual deposition of NH₄⁺ and NO₃^- was 0.103 mole N m^-2 yr^-1 was estimated to support 4% of the annual primary productivity in the East China Sea.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.1
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• pp.49-54
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• 2007

The issue of acid precipitation and related environmental problems in East Asia has been emerging. To evaluate the acidity and chemical characteristics of rainwater in Korea, its chemical properties during cultivation season from April to October in 2005 were investigated at Taean. Also, to estimate the contribution of ions on acidity, ion composition characteristics and neutralization effects by cations were determined. The electrical conductivity balance between measured and estimated values showed a high correlation. Rainwater was highly distributed in the range of pH $4.5{\sim}5.0$. The acidity of rainwater was relatively low during the month of June compared with other monitored periods. $Na^+$ was the main cation, followed by $H^+>Ca^{2+}>NH_4^+>K^+>Mg^{2+}$. Among these ions, $Na^+,\;NH_4^+,\;Ca^{2+}$ and $H^+$ comprised over 94% of the total cations. Rainwater anion composition was more than 80% with $SO_4^{2-}$ and $NO_3^-$. In rainwater samples, $NH_4^+$ and $Ca^{2+}$ contributed greatly to neutralizing the rain acidity. The sulfate content decreased until September, and sea salt derivatives were higher in May and October than during other monitored periods. Also, 78% of the soluble sulfate in rainwater was nss-$SO_4^{2-}$ (non-sea salt sulfate).

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.1
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• pp.1-5
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• 2003

This study was carried out to investigate the chemical properties of rainwater in the Suwon area. Rainwater was collected from April to October in 1999 and 2000, and its chemical composition was analyzed. The pH of rainwater in April was higher than that of the months after June. Occurrence frequency of rain above pH 5.6 was 45.1%, which showed the highest ratio from rainwater samples during the investigation periods. Those of pH 5.0∼5.6 and 4.5∼4.9 range were 31.4 and 19.6%, respectively. The major cations in rainwater were $Ca^{2+}$ and N $H_{4}$$^{+}$, and S $O_{4}$$^{2-}$ made up more than 50% of total anion composition. Monthly variation of neutralization capacity of rainwater acidity by $Ca^{2+}$ and N $H_{4}$$^{+}$ decreased during the rainy season. The ratio of non-sea salt sulfate to nitrate (nss-S $O_{4}$$^{2-}$/N $O_{3}$$^{[-10]}$ ) was 2.1, which means anthropogenic S $O_{4}$$^{2-}$ contributed to acidity of rainwater two times more than N $O_{3}$$^{[-10]}$ . .

• Korean Journal of Environmental Agriculture
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• v.20 no.4
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• pp.284-288
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• 2001

This study was carried out to investigate the chemical properties of rainwater in Taean area. Rainwater was collected during seven months from April to October in 2000, and analyzed for its chemical composition. The pH of rainwater at April and May were higher than those from June to September. Occurrence rate of rain above pH 5.6 was 42.1%, which showed the highest ratio from rainwater samples during investigation periods. Those of pH $5.0{\sim}5.6$ and $4.5{\sim}5.0$ range were 21.1 and 31.6%, respectively. The major cation in rainwater were $Ca^{2+}$ and $NH_4\;^+$, and $SO_4\;^{2-}$ was more than 50% of total anion composition. Monthly variation of acidity neutralization capacity by $Ca^{2+}$ and $NH_4\;^+$ was decreased during rainy season. The $nss-SO_4\;^{2-}/NO_3\;^-$, ratio was 2.0 which means $SO_4\;^{2-}$ contributed to acidity of rainwater two times more than $NO_3\;^-$.

• Korean Journal of Environmental Agriculture
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• v.18 no.2
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• pp.169-173
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• 1999

To investigate the chemical properties of rainwater in the southern part of gyeonggi Province, the rainwater was collected in Suwon and Ansung for six months from May to October in 1998, and analyzed its chemical composition. The ion balance and electric conductivity balance showed confidence to chemical analyses of rainwater. The most frequent pH range of rainwater was pH $5.0{\sim}5.6$ both in Suwon and Ansung area with distribution ratio of 37.9% and 35.3%, respectively. Among the 1mm fraction for initial 5mm of rainfall, ion concentration of initial rainwater (less than 1mm of rainfall) was higher than those of the later terms. The major ions in rainwater were $NH_4^-,\;Ca^{2+}$and $Na^+$ for cations, and $SO_4^{2-}$ and $NO_3^-$ for anions. Monthly variation of pH of rainwater showed low level of 4.2 to 4.5 in Suwon and 4.6 to 4.7 in Ansung in August and September, respectively. The $nss-SO_4^{2-}/NO_3^-$ ratio of rainwater in Suwon and Ansung area were 2.2 and 2.9 which means nonsea salt $SO_4^{2-}$ contrbuted to acidity of rainwater more in Ansung than Suwon area.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.2
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• pp.151-155
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• 2007

The issue of acid precipitation and related environmental problems in East Asia have been emerging. To evaluate the acidity and chemical characteristics of rainwater in Korea, its chemical properties during crop cultivation season from April to October were investigated at Suwon, Korea. Also, to estimate the contribution of ions on its acidity, ion composition characteristics and neutralization effects by cation ions were determined. Ion balance and electrical conductivity balance between the measured and estimated values showed high correlation. Rainwater had distributed highly in the range of pH 4.5~5.6. The pH of rainwater was relatively high at June as compared with other monitoring periods. $Na^+$ was the main cation followed by $NH_4{^+}$, $Ca^{2+}$, $H^+$ > $K^+$ > $Mg^{2+}$. Among these, $Na^+$, $NH_4{^+}$, $Ca^{2+}$ and $H^+$ covered over 93% of total cations. About 86% of anion in rainwater was composed of $SO{_4}^{2-}$ and $NO_3{^-}$. In rainwater samples, $NH_4{^+}$ and $Ca^{2+}$ contributed greatly to neutralization of the rain acidity. Also, 88% of soluble sulfate in rainwater was nss-$SO{_4}^{2-}$(non-sea salt sulfate).

• Korean Journal of Environmental Agriculture
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• v.18 no.3
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• pp.204-208
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• 1999

This study was carried out to investigate the chemical properties of rainwater in Taean area. The rainwater way collected for six months from May to Octotber in 1998, and analyzed its chemical composition. The ion balance and electric conductivity balance showed confidence to chemical analyses of rainwater. Distribution rates of pH of rainwater in Taean area were 43% and 38% in the range of pH $4.5{\sim}5.0$ and $5.0{\sim}5.6$, respectively. Among the 1mm fraction for initial 5mm of rainfall, ion concentration of initial rainwater (less than 1mm of rain) was higher than those of the later terms. The major ions in rainwater were $NH_4\;^+$ and $Ca_2\;^+$ for cations, and $SO_4\;^{2-}$ and $NO_3\;^-$ for anions. The pH value of rainwater showed the lowest level of 4.3 in August. The ratio of non-sea salt $SO_4\;^{2-}$ to $NO_3\;^-$ was 2.4.

• Bulletin of the Korean Chemical Society
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• v.24 no.3
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• pp.363-368
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• 2003

The major ionic components of precipitation collected at the 1100 Site of Mt. Halla and Jeju city have been determined. The reliability of the analytical data was verified by the comparison of ion balances, electric conductivities and acid fractions; all of their correlation coefficients were above 0.94. Ionic strengths lower than $10^{-4}$ M were found in 53% of the 1100 Site samples and 28% of the Jeju city samples. Compared with other inland areas, the wet deposition of $Na^+,\;Cl^-\;and\;Mg^{2+}$ was relatively larger, but that of $NH_4^+,\;nss-SO_4^{2-}$(non-sea salt sulfate) and $NO_3^-$ was lower. Especially the wet deposition increase of $Ca^{2+}$ in the spring season supports the possibility of the Asian Dust effect. The acidification of precipitation was caused mostly by $SO_4^{2-}\;and\;NO_3^-$ in the Jeju area, and the organic acids have contributed only about 7% to the acidity. The neutralization factors by NH₃were 0.47 and 0.48, and that of CaCO₃was 0.31 and 0.25 at the 1100 Site and Jeju city, respectively. Investigation into major influencing sources on precipitation components by factor analysis showed that the precipitation at the 1100 Site had been influenced mostly by an anthropogenic source, followed by soil and seawater sources. The precipitation at Jeju city was mainly influenced by oceanic sources, followed by anthropogenic and soil sources.

• Korean Journal of Agricultural and Forest Meteorology
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• v.6 no.4
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• pp.250-255
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• 2004

This study was carried out to investigate the chemical properties of rainwater in the Suwon and Taean areas. Rainwater was collected during the farming seasons of 2002 and 2003. The number of samples collected in Suwon and Taean were 69 and 71, respectively. These were analyzed for chemical composition. The pH of samples collected in April was higher than those collected after June. The most common range of rainwater pH was 5.0-5.6 in Suwon and 4.5-5.0 in Taean during investigation periods. The neutralization capacity of rainwater acidity by $Ca^{2+}$ and N $H_4$$^{+}$ was decreased during the rainy season. The EC of rainwater was lower during the rainy season. Cation concentrations in rainwater were N $H_4$$^{+}$ > $H^{+}$ > $Ca^{2+}$ > $Mg^{2+}$ > $K^{+}$ in Suwon and $Ca^{2+}$ > N $H_4$$^{+}$ > $H^{+}$ > $K^{+}$ > $Mg^{2+}$ in Taean. In the case of anion, the order was sol > N $O_3$$^{[-10]}$ > C $I^{[-10]}$ in Suwon and S $O_4$$^{2-}$ > C $I^{[-10]}$ > N $O_3$$^{[-10]}$ in Taean. The mean values of sulfate in rainwater were 130 $\mu$eq $L^{-1}$ in Suwon and 117 $\mu$eq $L^{-1}$ in Taean. The ratio of non-sea salt sulfate to sulfate (nss-S $O_4$$^{2-}$ > S $O_4$$^{2-}$) was 89% and 88%. This implies that the major origin of sulfate in rainwater might be anthropogenic.ht be anthropogenic..