The IAGOS NO<sub><i>x</i></sub> instrument – design, operation and first results from deployment aboard passenger aircraft

Abstract

Abstract. We describe the nitrogen oxide instrument designed for the autonomous operation on board passenger aircraft in the framework of the European Research Infrastructure IAGOS (In-service Aircraft for a Global Observing System). 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 measuring at high time resolution (4 s) and high precision in the low ppt range (NO: 2σ = 24 pptv; NO x : 2σ = 35 pptv) 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; nitrous acid, HONO; peroxyacetyl nitrate, PAN) and (3) inter-instrumental precision. We demonstrate that the IA-GOS NO x instrument is a robust, fully automated, and longterm stable instrument suitable for unattended operation on airborne platforms, which provides useful measurements for future air quality studies and emission estimates.

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

“…There are also NO 2 observations from the recent NASA ATom campaign and from the In-service Aircraft for a Global Observing System (IAGOS) commercial aircraft campaign (Berkes et al, 2018). These use chemiluminescence instruments that are also susceptible to interference.…”

The influence of typhoons on atmospheric composition deduced from IAGOS measurements over Taipei

“…The fact that IAGOS aircraft from China Airlines operate from the TPE airport is an excellent opportunity, considering the frequent occurrence of typhoons in the vicinity of Taiwan. IAGOS offers additional instrumentation to measure NO x , which is available on one aircraft so far (Berkes et al, 2018). In future it is hoped that NO x instruments on China Airlines could help to determine the amount of lightning NO x produced in the vicinity of typhoons.…”

“…At these altitudes, the correlations amongst the different trace gases can give insights into various mixing processes near the tropopause (e.g Hoor et al, 2002;Pan et al, 2004;Hegglin et al, 2009;Tilmes et al, 2010). Brioude et al (2006) used IAGOS observations and Lagrangian analysis to confirm that a layer of enhanced ozone with low carbon monoxide and low relative humidity was due to a tropopause fold associated with a mid-latitude cyclone. More recently, a stratospheric intrusion associated with tropopause folds along the jet-stream axis of an upperlevel trough over Europe was captured by IAGOS observations (Akriditis et al, 2018).…”

The influence of typhoons on atmospheric composition deduced from IAGOS measurements over Taipei

“…The fact that IAGOS aircraft from China Airlines operate from TPE airport is an excellent opportunity, considering the frequent occurrence of typhoons in the vicinity of Taiwan. IAGOS offers additional instrumentation to measure NOx which is available on one aircraft so far (Berkes et al 2018). In the future it is hoped that NOx instruments on China airlines could help to determine the amount of lightning NOx produced in the vicinity of typhoons.…”