A Database of Aircraft Carbon Monoxide (CO) Measurements with High Temporal and Spatial Resolution during 2011 – 2021

To understand tropospheric air pollution at a regional/global scale, the SPIRIT airborne instrument (SPectromètre Infra-Rouge In situ Toute altitude) was developed in 2011 and used on aircraft to measure CO, an important indicator of air pollution, during the last decade. SPIRIT could provide high-quality CO measurements with 1σ precision of 0.3 ppbv at a time resolution of 1.6 s. It can be operated on different aircraft from DLR (Germany) and SAFIRE (CNRS-CNES-Météo France) such as Falcon-20 and ATR-42. With support from various projects, more than 200 flight hours measurements were conducted over three continents (Europe, Asia, Africa), including two inter-continental transect measurements (Europe-Asia and Europe-Africa). Levels of CO and its horizontal and vertical distribution are briefly discussed and compared between different regions/continents. A 3D trajectory mapped by CO level was plotted for each flight and presented in this study. The database containing all the raw data will be archived on the AERIS database (www.aeris-data.fr), the French national center for Earth observation dedicated to the atmosphere. The database can help to understand the horizontal and vertical distribution of CO over different regions and continents. Besides, it can help to validate model performance and satellite measurements. For instance, the database covers measurements at high-latitude regions (i.e., Kiruna, Sweden, 68˚N) where satellite measurements are still a challenge, and at low-latitude regions (West Africa and South-East Asia) where in situ data are scarce and satellites need more validation by airborne measurements.