Vertical nitrogen dioxide and ozone concentrations measured from a tethered balloon in the Lower Fraser Valley

Abstract

Abstract-A series of vertical profiles of temperature, relative humidity, N0 2 and 0, were determined in lhe Lower Fraser Valley, British Columbia, as part oClhe PACIFIC '93 field study. Data from one day show very slructured vertical distributions of all parameters in the morning, as expected from the limited vertical mixing under the nocturnal inversion. N0 2 concentrations of 20ppbv were observed 300 m above the surface, while the surface concentrations were -2 ppbv. Ozone and nitrogen oxide chemislry were observed at all altitudes throughout the PBL. Titration of 0, by NO to produce N0 2 was observed in layers above the ground, under the influence of the NBL. An increase in odd oxygen lhroughout lhe PBL, during the morning and early afternoon, shows "smog chemistry" is occurring even though the groundbased 0J measurements suggest this day was not particularly chemically active. However, once the NBL has dissipated, the ground-based measurements seem representative of lhe entire PBL.

Vertical profiles of O<sub>3</sub> and NO<sub>x</sub> chemistry in the polluted nocturnal boundary layer in Phoenix, AZ: I. Field observations by long-path DOAS

“…3, strong vertical variations of NO 2 and O 3 mixing ratios were observed. The negative NO 2 gradient and positive O 3 gradient agree well with earlier observations in various rural and suburban areas (Glaser et al, 2003;Pisano et al, 1997;Stutz et al, 2004b), but with significantly larger magnitudes due to the higher emission rates in downtown Phoenix. The gradients were sustained until the morning hours and then gradually disappeared after the onset of convective mixing.…”

“…Vertical distribution measurements of O 3 , NO 2 , temperature and relative humidity in a suburban area show persistent vertical profiles for several hours after sunrise in some cases (Pisano et al, 1997). A similar trend has been found in the vertical profiles of O 3 , NO 2 , NO x , selected VOCs and meteorological parameters after very stable nights at a rural site (Glaser et al, 2003).…”

“…As a result, a stable nocturnal boundary layer (NBL), which is capped by a relatively well-mixed residual layer (RL) with neutral stability, develops. Due to the weak vertical mixing, ground-level emissions in urban areas accumulate near the surface throughout the night (Doran et al, 2003;Garland and Branson, 1976;Pisano et al, Published by Copernicus GmbH on behalf of the European Geosciences Union.…”

“…The study of chemistry in the NBL, especially in polluted urban areas, is thus quite challenging Stutz et al, 2004b). The altitude dependence of both chemistry and vertical trace gas profiles vanish during the morning hours when surface heating leads to convection and accelerates vertical exchange (Doran et al, 2003;Garland and Branson, 1976;Pisano et al, 1997).…”

A Bird’s-Eye View: Development of an Operational ARM Unmanned Aerial Capability for Atmospheric Research in Arctic Alaska

“…They offer the benefit of extended flight times during times of good weather conditions, but fall short of the UASs in terms of flexibility when sampling a targeted spatial location or in capturing gradients across boundaries. Example applications include the measurement of atmospheric composition and structure (e.g., Greenberg 1999;Pisano et al 1997;Neff et al 2008;Shupe et al 2012) and cloud microphysical properties (e.g., Duda et al 1991;Kitchen and Caughey 1981;Zhang et al 1997).…”