caa a22 4500 467902704 CHVBK 20180406152823.0 cr unu---uuuuu 170328e20060701xx s 000 0 eng 10.1007/s10661-006-0772-7 doi (NATIONALLICENCE)springer-10.1007/s10661-006-0772-7 The Characteristics of Tropospheric Ozone Seasonality Observed from Ozone Soundings at Pohang, Korea [Elektronische Daten] [Jae Kim, H. Lee, S. Lee] This paper presents the first analysis of vertical ozone sounding measurements over Pohang, Korea. The main focus is to analyze the seasonal variation of vertical ozone profiles and determine the mechanisms controlling ozone seasonality. The maxima ozone at the surface and in the free troposphere are observed in May and June, respectively. In comparison with the ozone seasonality at Oki (near sea level) and Happo (altitude of 1840 m) in Japan, which are located at the same latitude as of Pohang, we have found that the time of the ozone maximum at the Japanese sites is always a month earlier than at Pohang. Analysis of the wind flow at the surface shows that the wind shifts from westerly to southerly in May over Japan, but in June over Pohang. However, this wind shift above boundary layer occurs a month later. This wind shift results in significantly smaller amounts of ozone because the southerly wind brings clean wet tropical air. It has been suggested that the spring ozone maximum in the lower troposphere is due to polluted air transported from China. However, an enhanced ozone amount over the free troposphere in June appears to have a different origin. A tongue-like structure in the time-height cross-section of ozone concentrations, which starts from the stratosphere and extends to the middle troposphere, suggests that the ozone enhancement occurs due to a gradual migration of ozone from the stratosphere. The high frequency of dry air with elevated ozone concentrations in the upper troposphere in June suggests that the air is transported from the stratosphere. HYSPLIT trajectory analysis supports the hypothesis that enhanced ozone in the free troposphere is not likely due to transport from sources of anthropogenic activity. Springer Science + Business Media, Inc., 2006 ozone seasonality nationallicence stratosphere-troposphere exchange nationallicence tropospheric ozone nationallicence Kim Jae Department of Atmospheric Science, Pusan National University, 609-735, Pusan, Korea aut Lee H. Korea Meteorological Research Institute, Korea aut Lee S. Korea Meteorological Research Institute, Korea aut Environmental Monitoring and Assessment Kluwer Academic Publishers 118/1-3(2006-07-01), 1-12 0167-6369 118:1-3<1 2006 118 10661 https://doi.org/10.1007/s10661-006-0772-7 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10661-006-0772-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kim Jae Department of Atmospheric Science, Pusan National University, 609-735, Pusan, Korea aut NATIONALLICENCE 700 1- Lee H. Korea Meteorological Research Institute, Korea aut NATIONALLICENCE 700 1- Lee S. Korea Meteorological Research Institute, Korea aut NATIONALLICENCE 773 0- Environmental Monitoring and Assessment Kluwer Academic Publishers 118/1-3(2006-07-01), 1-12 0167-6369 118:1-3<1 2006 118 10661 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer