7Be and210Pb radioactivity and implications on sources of surface ozone at Mt. Waliguan

Zheng, Xiaodong; Wang, Guojiang; Tang, Jie; Zhang, Xiaochun; Yang, Wei; Lee, H. N.; Wang, Changsheng

doi:10.1007/bf02897521

Cited by 12 publications

(7 citation statements)

References 13 publications

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“…In the Pacific and Atlantic regions, the stratosphere-troposphere exchange occurs predominantly over storm tracks during winter, spring, and fall 12 13 14 15 16 17 18 19 ; Taiwan is located in such a region. In summer the exchange maximizes its amplitude over the central Asia, supported by various observations made at the Waliguan Observatory (36°17´ N, 100°54´ E, 3816 m, China; NOAA ESRL code: WLG) located on the Tibetan Plateau 20 21 22 23 24 25 26 . In the mid-latitudes of East Asia, ozonesonde and surface observations show a distinct spring maximum (e.g., see ref.…”

mentioning

confidence: 61%

Oxygen anomaly in near surface carbon dioxide reveals deep stratospheric intrusion

Liang

Mahata

2015

Sci Rep

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Stratosphere-troposphere exchange could be enhanced by tropopause folding, linked to variability in the subtropical jet stream. Relevant to tropospheric biogeochemistry is irreversible transport from the stratosphere, associated with deep intrusions. Here, oxygen anomalies in near surface air CO2 are used to study the irreversible transport from the stratosphere, where the triple oxygen isotopes of CO2 are distinct from those originating from the Earth’s surface. We show that the oxygen anomaly in CO2 is observable at sea level and the magnitude of the signal increases during the course of our sampling period (September 2013-February 2014), concordant with the strengthening of the subtropical jet system and the East Asia winter monsoon. The trend of the anomaly is found to be 0.1‰/month (R2 = 0.6) during the jet development period in October. Implications for utilizing the oxygen anomaly in CO2 for CO2 biogeochemical cycle study and stratospheric intrusion flux at the surface are discussed.

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mentioning

confidence: 61%

Oxygen anomaly in near surface carbon dioxide reveals deep stratospheric intrusion

Liang

Mahata

2015

Sci Rep

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“…The atmosphere in this region is relatively unaffected by anthropogenic activities on the Asian continent because of its unique geographic nature, sparse population, and the minimal industrial activities in western China [ Wang et al ., ]. Analyses of O 3 together with tropospheric and stratospheric tracers such as water vapor, CO, nonmethane hydrocarbons [ Wang et al ., ; Ding and Wang , ], and 7 Be [ Lee et al ., ; Zheng et al ., ] suggest a stratospheric source for the summertime O 3 peak at WLG. However, chemical transport modeling studies suggest that the summer O 3 maximum at WLG results from the transport of anthropogenic effects from central and eastern China [ Zhu et al ., ; Li et al ., ].…”

Section: Introductionmentioning

confidence: 99%

Analysis of the seasonal ozone budget and the impact of the summer monsoon on the northeastern Qinghai‐Tibetan Plateau

2016

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Seasonal variations in ozone (O3) and the impact of the East Asian summer monsoon at Mount Waliguan (WLG) in the northeastern Qinghai‐Tibetan Plateau (TP) and in the surrounding regions were analyzed for 1997–2007 using a global chemical transport model coupled with O3 tagging simulations. The model‐simulated O3 and its precursors agreed well with observed values. An O3 budget analysis combined with O3 tagging results implied that photochemistry over the TP and long‐range transport of O3 from East Asia, Europe, and Africa were responsible for the surface O3 summer maximum at WLG. In June, the contribution of O3 from the TP was 11.8 ppbv, and the total contribution of O3 transport from eastern China, Japan, Korean Peninsula, Europe, and Africa was 22.7 ppbv. At 400 mb, the O3 exports from the stratosphere, Europe, Africa, and the Americas seemed to be the main sources of O3 at WLG. The contributions to surface O3 from deep convection process and lightning‐induced photochemistry at WLG were both low in summer and are unlikely to be the key processes or contributors for the O3 peak. At several mountain sites in southeast East Asia, the increasing summer monsoon index was related to a decreasing trend for O3 from spring onward at Mount Tai and Mount Huang. At Mount Hua and WLG, regional O3 accumulated over the monsoon's northernmost marginal zone under the influence of the East Asian summer monsoon and TP thermal circulation; this is most likely a key reason for the O3 summer maxima.

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“…Fuji, 35.35°N, 138.73°E, 3776 m amsl and Mauna Loa, 19.5°N, 155.6°W, 3397 m amsl) show a springtime maximum value which is largely explained on the basis of downward transport of ozone‐rich air from higher altitudes [e.g., Tsutsumi et al , 1994; Oltmans et al , 2006] while there have been different explanations of the summertime maximum value observed at Waliguan (36.28°N, 100.9°E, 3810 m amsl) [ Tang et al , 1995]. Zhu et al [2004] proposed that transport of polluted air masses from eastern/central China and central/south Asia is responsible for the summertime maximum at Waliguan while other studies [e.g., Ma et al , 2005; Zheng et al , 2005; Ding and Wang , 2006] have suggested that subsidence of upper tropospheric/stratospheric air over Tibetan plateau brings ozone‐rich air to the surface there in summer. Springtime maximum ozone levels observed at Arosa (46.77°N, 9.47°E, 1840 m amsl) and Mt.…”

Section: Introductionmentioning

confidence: 99%

Variations in surface ozone at Nainital: A high‐altitude site in the central Himalayas

Kumar¹,

Naja²,

Venkataramani³

et al. 2010

J. Geophys. Res.

122

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[1] Surface ozone measurements have been made for the first time at Nainital (29. 37°N, 79.45°E, 1958 m amsl), a high-altitude site in the central Himalayas, between October 2006 and December 2008. Diurnal variations in ozone do not show the daytime photochemical build-up typical of urban or rural sites. The seasonal variation shows a distinct ozone maximum in late spring (May; 67.2 ± 14.2 ppbv) with values sometimes exceeding 100 ppbv and a minimum in the summer/monsoon season (August; 24.9 ± 8.4 ppbv). Springtime ozone values in the central Himalayas are significantly higher than those at another highaltitude site (Mt. Abu) in the western part of India. Seasonal variations in ozone and the processes responsible for the springtime peak are studied using meteorological parameters, insolation, spatial and temporal classifications of air mass trajectories, fire counts, and simulations with a chemical transport model. Net ozone production over the Northern Indian Subcontinent in regionally polluted air masses is estimated to be 3.2 ppbv/day in spring but no clear build-up is seen at other times of year. Annual average ozone values in regionally polluted air masses (47.1 ± 16.7 ppbv) and on high insolation days (46.8 ± 17.3 ppbv) are similar. Background ozone levels are estimated to be 30-35 ppbv. Regional pollution is shown to have maximum contribution (16.5 ppbv) to ozone levels during May-June and is about 7 ppbv on an annual basis, while the contribution of long-range transport is greatest during January-March (8-11 ppbv). The modeled stratospheric ozone contribution is 2-16 ppbv. Both the trajectory analysis and the model suggest that the stratospheric contribution is 4-6 ppbv greater than the contribution from regional pollution. Differences in the seasonal variation of ozone over high-altitude sites in the central Himalayas (Nainital) and western India (Mt. Abu) suggest diverse regional emission sources in India and highlight the large spatial and temporal variability in ozone over the Indian region.

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7Be and210Pb radioactivity and implications on sources of surface ozone at Mt. Waliguan

Cited by 12 publications

References 13 publications

Oxygen anomaly in near surface carbon dioxide reveals deep stratospheric intrusion

Oxygen anomaly in near surface carbon dioxide reveals deep stratospheric intrusion

Analysis of the seasonal ozone budget and the impact of the summer monsoon on the northeastern Qinghai‐Tibetan Plateau

Variations in surface ozone at Nainital: A high‐altitude site in the central Himalayas

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