Earth atmosphere
; Nitrogen
; Ozone
; Ozone layer
; Photochemical reactions
; Solar radiation
; Chemical process
; Cryosphere
; Diurnal cycle
; Gas exchange
; Meteorological effects
; Mixing ratios
; Shallow layers
; Yield enhancement
; Nitrogen oxides
; nitrogen oxide
; ozone
; snow
; ambient air
; atmospheric chemistry
; climate effect
; cryosphere
; diurnal variation
; gas exchange
; interstitial environment
; nitrogen oxides
; ozone
; photochemistry
; seasonality
; snowpack
; solar radiation
; trace gas
; air conditioning
; ambient air
; Article
; autumn
; chemical reaction
; circadian rhythm
; concentration (parameters)
; night
; priority journal
; solar cycle
; solar radiation
; spring
; summer
; time series analysis
; wind
; Arctic
; Greenland
; Summit
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:
A multi-year investigation of ozone (O3) and nitrogen oxides (NOx) in snowpack interstitial air down to a depth of 2.8 m was conducted at Summit, Greenland, to elucidate mechanisms controlling the production and destruction of these important trace gases within the snow. Snowpack O3 values ranged from 30 to 40 ppbv during winter months, and dropped below 10 ppbv in summer. Wintertime NOx levels were low at all depths in the snowpack (below 10 pptv for NO and below 25 pptv for NO2). In the summer, NO values up to 120 pptv, and NO2 mixing ratios up to ∼700 pptv were observed. O3 loss within the snowpack was observed throughout all seasons. The magnitude of the O3 loss rate tracked the seasonal and diurnal cycle of incoming short wave solar radiation. Production of NO within a shallow layer of the snowpack was recorded during the spring and summer months. NO2 production also occurred, and heightened levels were measured down to 2.5 m in the snowpack. The average daily maximum in NO was observed at solar noon, and the minimum was seen during night. The daily peak in NO2 was on average 7 h shifted from the incoming solar radiation and NO maxima. NOx levels in interstitial air during spring were enhanced relative to summer and fall. The influence of meteorological effects such as wind pumping on snowpack interstitial air levels of O3 and NOx was investigated using case study periods. Increased snowpack ventilation during high wind events was found to yield enhancement in snowpack NOx, with this effect being enhanced during times when O3 was elevated in ambient air. This behavior suggests that O3 is involved in NOx production in the snowpack. This extensive set of observations is used to re-evaluate physical and chemical processes that describe the dynamic O3 and NOx chemistry occurring within snowpack interstitial air at Summit. � 2015 Elsevier Ltd.
Institute of Arctic and Alpine Research, University of Colorado at BoulderCO, United States; Department of Geological and Mining Engineering and Sciences, Michigan Technological University, Houghton, MI, United States; Department of Civil and Environmental Engineering, Washington State University, Pullman, WA, United States; Department of Civil and Environmental Engineering, Michigan Technological University, Houghton, MI, United States; School of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI, United States; Atmospheric Sciences Program, Michigan Technological University, Houghton, MI, United States; Department of Environmental Sciences, Wageningen University, Wageningen, Netherlands
Recommended Citation:
Van Dam B,, Helmig D,, Toro C,et al. Dynamics of ozone and nitrogen oxides at Summit, Greenland: I. Multi-year observations in the snowpack[J]. Atmospheric Environment,2015-01-01,123(Part A)