Development of a semi-continuous measurement system for the carbonaceous fraction in ambient aerosol

Abstract

Within the framework of the MeteoSwiss Global Atmosphere Watch (GAW) program GAW-Plus 2018-2021, we are developing a carbonaceous aerosol measurement system for long-term mon-itoring of total carbon (TC). The instrument will be a redesign of the FAst Thermal CArbon Totali-zator (FATCAT), a successfully tested technology for emission monitoring developed by our research group. The standardization and the development of a simplified continuous TC meas-urement method aim to fill a major gap in the GAW aerosol monitoring program, i.e., to provide an affordable method of carbonaceous aerosol measurement at monitoring sites and to assure comparability of data measured by different research groups. Planed activities include several unsupervised long-term measurement campaigns at monitoring stations, within the Swiss Na-tional Air Pollution Monitoring Network (NABEL) network as well as on the GAW Jungfraujoch site, which are influenced by different types of carbonaceous aerosol throughout the year. The resulting dataset and post-analysis data products represent an upgrade to the available meas-urement inventory and serve as quality control for other measurement techniques. Prominently, measurements of equivalent black carbon via MAAP or Aethalometer and organic mass using AMS or ToF-ACSM require calibration and are susceptible to systematic errors. Our unattended semi-online TC measurement can be used in parallel to these devices to warranty mass closure.