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Meehye Lee, Birgitta C. Noone, Daniel O'sullivan, and Brian G. Heikes

Abstract

An HPLC (high-performance liquid chromatography) method was developed to quantify hydrogen peroxide, methyl hydroperoxide. Hydroxymethyl hydroperoxide, ethyl hydroperoxide, and peroxyaectic acid in the atmosphere. Gas-phase hydroperoxides are collected in aqueous solution using a continuous-flow glass scrubbing coil and then analyzed by an HPLC postcolumn derivatization system. The detection system is based on fluorescence, produced by the product of the reaction of hydroperoxides with peroxidase and p-hydroxyphenylacetic acid. Reproducibilities are better than 3% for all hydroperoxides in aqueous concentrations of 1 × 10−7–6 × 10−7 M. Detection limits in aqueous concentration are 1.2 × 10−9 M for hydrogen peroxide, 1.5 × 10−9 M for hydroxymethyl hydroperoxide, 2.9 × 10−9 M for methyl hydroperoxide, 16 × 10−9 M for peroxyaectic acid, and 19 × 10−9 M for ethyl hydroperoxide. Corresponding gas-phase detection limits are 5 PPtv for hydrogen peroxide, 7 pptv for hydroxymethyl hydroperoxide, 13 pptv for methyl hydroperoxide, 72 pptv for peroxyacetic acid, and 84 pptv for ethyl hydroperoxide for an air sample flow rate of two standard liters per minute and collection solution flow rate of 4 × 10−4 L min−1. The gas-phase detection limits for the latter three hydroperoxides vary depending on temperature, pressure, air sample flow rate, and collection solution flow rate. This system was used for several airborne and ground measurements and showed reliable performance.

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Youngsin Chun, Hi-Ku Cho, Hyo-Sang Chung, and Meehye Lee

The observation of dust events in Korea must have been important through its long history because of its geographical and meteorological setting. Descriptions about dust events were well documented in historical archives, such as Samguk sagi (57 BC–AD 938), Goryeo sa (918–1392), Joseon wangjosillok (1392–1853), and Munhuenbigo (~1776). In this study, records of Asian dust events were compiled from the above historical archives, covering the period of the second to the eighteenth century. These historical records were investigated along with the recent data (1915–2005) of dust event days in Seoul, Korea. The first record was made in AD 174 in Silla during the period of the Three Kingdoms. A dust event, now called hwangsa, was commonly written down as Woo-Tou or Tou-Woo standing for “dustfall” in the historical archives. Asian dust events took place most frequently during spring from March to May and there was almost no occurrence in summer. The main seasonal feature of the historical dust events was found to be in good agreement with that of the last 90 yr. The result suggests that the past seasonal mechanism of the dust event occurrence and transport in northeast Asia is not significantly different from the present.

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Kyung-Ja Ha, SungHyun Nam, Jin-Yong Jeong, Il-Ju Moon, Meehye Lee, Junghee Yun, Chan Joo Jang, Yong Sun Kim, Do-Seong Byun, Ki-Young Heo, and Jae-Seol Shim

Abstract

The main purposes for establishing the Korea ocean research stations (KORS) are for advancing an overall understanding of atmospheric and oceanic phenomena in the Yellow and East China Seas; for providing core scientific data for the studies on global environmental change, typhoon dynamics, biogeochemical cycles, marine ecosystems and fisheries, atmospheric chemistry involving Asian dust and aerosols, air–sea interaction processes including sea fog, and regional oceanographic process studies; and for functioning as ground stations of ocean remote sensing. Here, ocean–atmosphere time series observations with data service and case studies of KORS applications that will facilitate collaboration among researchers in the international atmospheric and oceanographic communities are presented.

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