The IAGOS NO<sub>x</sub> Instrument – Design, Operation and First Results from Deployment aboard Passenger Aircraft

Abstract

We describe the nitrogen oxides instrument designed for the autonomous operation on board of passenger aircraft in the framework of the European Research Infrastructure IAGOS (In-service Aircraft for a Global 10Observing System, www.iagos.org). We demonstrate the performance of the instrument using data from two deployment periods aboard an A340-300 aircraft of Deutsche Lufthansa. The well-established chemiluminescence detection method is used to measure nitrogen monoxide (NO) and nitrogen oxides (NO x ). NO x is measured using a photolytic converter, and nitrogen dioxide (NO 2 ) is determined from the difference between NO x and NO. This technique allows to measure at high time resolution (4s) and high precision (2σ) in 15 the low ppt range (NO of 24 ppt and NO x of 35 ppt) over different ambient temperature and ambient pressure altitude ranges (from surface pressure down to 190 hPa). The IAGOS NO x instrument is characterized for (1) calibration stability and total uncertainty (2) humidity and chemical interferences (e.g. ozone, HONO, PAN) and (3) inter-instrumental precision. We demonstrate that the IAGOS NO x instrument is a robust, fully automated, and long-term stable instrument suitable for unattended operation on airborne platforms, which provides useful 20 measurements for future air quality studies and emission estimates.Atmos. Meas. Tech. Discuss., https://doi

Nitrogen oxides in the global upper troposphere: interpreting cloud-sliced NO<sub>2</sub> observations from the OMI satellite instrument

“…Observing System (IAGOS) commercial aircraft campaign (Berkes et al, 2017). These use chemiluminescence instruments that 150 are also susceptible to interference.…”