DOI: 10.1016/j.atmosenv.2017.06.042
Scopus记录号: 2-s2.0-85021432352
论文题名: Trends and sources of ozone and sub-micron aerosols at the Mt. Bachelor Observatory (MBO) during 2004–2015
作者: Zhang L ; , Jaffe D ; A
刊名: Atmospheric Environment
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2017
卷: 165 起始页码: 143
结束页码: 154
语种: 英语
英文关键词: Backward trajectories
; Enhancement ratios
; Long-term trends
; Sub-micron aerosols
; Tropospheric ozone
; Western US
Scopus关键词: Aerosols
; Air quality
; Atmospheric movements
; Carbon monoxide
; Fires
; Observatories
; Ozone
; Ozone layer
; Pollution
; Residence time distribution
; Troposphere
; Backward trajectory
; Enhancement ratios
; Long-term trend
; Submicron aerosol
; Tropospheric ozone
; Air pollution
; carbon monoxide
; ozone
; absorption
; aerosol
; air mass
; air quality
; atmospheric pollution
; biomass burning
; boundary layer
; carbon monoxide
; long range transport
; residence time
; troposphere
; water vapor
; absorption
; aerosol
; air
; air pollution
; Article
; autumn
; biomass
; boundary layer
; burn
; fire
; mineral dust
; Oregon
; particle size
; plume
; priority journal
; smoke
; spring
; stratosphere
; summer
; trend study
; troposphere
; water vapor
; winter
; Arctic
; Massachusetts
; Oregon
; Pacific Northwest
; Salem [Massachusetts]
; United States
Scopus学科分类: Environmental Science: Water Science and Technology
; Earth and Planetary Sciences: Earth-Surface Processes
; Environmental Science: Environmental Chemistry
英文摘要: In this paper, we report the climatology of tropospheric ozone (O3) and sub-micron aerosol scattering at the Mt. Bachelor Observatory (MBO, 2.8 km asl) in central Oregon, USA, during 2004–2015. The seasonal cycle for O3 showed a bimodal pattern with peaks in April and July, while aerosol scattering (σsp) was lognormally distributed with a very high peak in August and a smaller peak in May. The mean O3 concentrations showed positive and significant trends in all seasons except winter, with a slope of 0.6–0.8 ppbv yr−1. Monthly criteria for isolating free tropospheric (FT) and boundary layer influenced (BLI) air masses at MBO were obtained based on comparison of MBO water vapor (WV) distributions to those of Salem (SLE) and Medford (MFR), Oregon, at equivalent pressure level. In all seasons, FT O3 was, on average, higher than BLI O3, but the seasonal patterns were rather similar. For σsp the FT mean in spring was higher, but the BLI mean in summer was significantly higher, indicating the importance of regional wildfire smoke. To better understand the causes for the seasonal and interannual trends at MBO, we identified four major categories of air masses that impact O3, carbon monoxide (CO) and aerosols: upper troposphere and lower stratosphere (UTLS) O3 intrusion, Asian long-range transport (ALRT), Arctic air pollution (AAP) and plumes from the Pacific Northwest region (PNW). ALRT and PNW plumes can be further divided into wildfires (WF), industrial pollution (IP) and mineral dust (MD). Over the 12 years of observations, 177 individual plume events have been identified. Enhancement ratios (ERs) and Ångström exponents (AEs) of aerosols were calculated for all events. The lowest slope of Δσsp/ΔO3 is a unique feature of UTLS events. PNW-WF events have the highest averages for Δσsp/ΔCO, Δσsp/ΔO3 and Δσsp/ΔNOy compared to other events. These ERs decrease during long-range transport due to the shorter residence time of aerosols compared to the other pollutants. ALRT-WF events have lower absorption AEs (Åap) than PNW-WF, implying that brown carbon (BrC) is generated from biomass burning but its fraction decreases during long-range transport. Signatures of ERs and AEs are useful tools to identify different plume categories. These results demonstrate the increasing impact of baseline O3 on US air quality due to both global sources and regional wildfire events. © 2017 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/82409
Appears in Collections: 气候变化事实与影响
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作者单位: School of Science, Technology, Engineering and Mathematics, University of Washington Bothell, Bothell, WA, United States; Department of Atmospheric Sciences, University of Washington, Seattle, WA, United States
Recommended Citation:
Zhang L,, Jaffe D,A. Trends and sources of ozone and sub-micron aerosols at the Mt. Bachelor Observatory (MBO) during 2004–2015[J]. Atmospheric Environment,2017-01-01,165