The development of a nitrogen dioxide sonde

Abstract

A growing number of space-borne instruments measures nitrogen dioxide (NO<sub>2</sub>) concentrations in the troposphere, but validation of these instruments is hampered by lack of ground-based and in-situ profile measurements. <br><br> The Royal Netherlands Meteorological Institute (KNMI) has developed a working NO<sub>2</sub> sonde. The sonde is attached to a small meteorological balloon and measures a tropospheric NO<sub>2</sub> profile. The NO<sub>2</sub> sonde has a vertical resolution of 5 m, and a measurement range between 1 and 100 ppbv. The instrument is light in weight (±700 g), cheap (disposable), energy efficient and not harmful to the environment or the person who finds the package after use. The sonde uses the chemiluminescent reaction of NO<sub>2</sub> in an aqueous luminol solution. The NO<sub>2</sub>–luminol reaction produces faint blue/purple light (at about 425 nm), which is detected by an array of silicon photodiodes. The luminol solution is optimised to be specific to NO<sub>2</sub>. <br><br> An on-ground comparison with measurements from a Photolytic Analyzer of RIVM shows that both instruments measure similar NO<sub>2</sub> variations in ambient air. <br><br> During the Cabauw Intercomparison campaign of Nitrogen Dioxide measuring Instruments (CINDI) in June/July 2009 six vertical profiles of NO<sub>2</sub> from the ground to 5 km altitude were measured, which clearly show that the largest amount of NO<sub>2</sub> is measured in the boundary layer. The measured boundary layer heights of the NO<sub>2</sub> sonde are in good agreement with boundary layer heights determined by a LD40 Ceilometer at Cabauw

Estimating surface NO2 and SO2 mixing ratios from fast-response total column observations and potential application to geostationary missions

“…This analysis shows the correlation between surface NO 2 and column observations supporting the initial assumption that daytime tropospheric NO 2 is predominantly located within the PBL (Pisano et al 1996 ; Sitnikov et al 2005 ; Sluis et al 2010 ), that, to first order, column observations can be used for estimating surface NO 2 mixing ratios at the locations studied, and that information content in temporally-short observations may be significant enough to detect surface variability from geostationary space-based instruments (e.g. GEO-CAPE) with continental coverage.…”

“…It has been well documented that NO 2 mixing ratios are often highly variable within the PBL (e.g. Halla et al 2011 ; Piters et al 2012 ; Sluis et al 2010 ; Volten et al 2009 ; Yang et al 2010 ). However, the ability for making NO 2 -profile measurements was not available throughout the entire measurement period; therefore, it is assumed here that surface emissions are well-mixed within the PBL as a first-order approximation (Leigh et al 2007 ).…”

“…This approximation is good, since the calculated day-to-day stratospheric variability is small (within 5 × 10 14 mol.cm −2 , or ≈10 % of the total column under polluted conditions). Because of nitrogen dioxide’s short photolytic lifetime outside the boundary layer, and temperature-dependent partitioning between NO 2 and NO, most of the tropospheric NO 2 column density resides in the PBL (Pisano et al 1996 ; Sitnikov et al 2005 ; Sluis et al 2010 ; Fishman et al 2011 ) and, under polluted conditions, the stratospheric contribution/variability is relatively minor throughout the day.…”

Linking NO2 surface concentration and integrated content in the urban developed atmospheric boundary layer

“…The main problem is that no relationship has been proven to be reliably usable to deduce the surface concentration from the measured integrated content. Indeed, to our knowledge, no NO 2 concentration profile has ever been measured over urban areas, though they are new developments, for example, using Multi‐Axis Differential Optical Absorption Spectroscopy (MAX‐DOAS) [ Irie et al ., ] or radiosondes [ Sluis et al ., ]. As a consequence, linking NO 2 surface concentration to the integrated content in the ABL requires an hypothesis on NO 2 vertical distribution in the ABL.…”

Atmospheric NO2 profiles measured with lidar during the CINDI-2 campaign

“…On some of the campaign days, one or more balloon sondes with fast NO2 sensors [6] were launched. These reached altitudes of typically 10 km.…”