A dedicated flask sampling strategy developed for Integrated Carbon Observation System (ICOS) stations based on CO2 and CO measurements and Stochastic Time-Inverted Lagrangian Transport (STILT) footprint modelling

0533147 - ÚVGZ 2021 RIV DE eng J - Journal Article
Levin, I. - Karstens, U. - Eritt, M. - Maier, F. - Arnold, S. - Rzesanke, D. - Hammer, S. - Ramonet, M. - Vítková, Gabriela - Conil, S. - Heliasz, M. - Kubistin, D. - Lindauer, M.
A dedicated flask sampling strategy developed for Integrated Carbon Observation System (ICOS) stations based on CO2 and CO measurements and Stochastic Time-Inverted Lagrangian Transport (STILT) footprint modelling.
Atmospheric Chemistry and Physics. Roč. 20, sep (2020), s. 11161-11180. ISSN 1680-7316. E-ISSN 1680-7324
R&D Projects: GA MŠMT(CZ) LM2015061
Institutional support: RVO:86652079
Keywords : icos * flask sampling
OECD category: Meteorology and atmospheric sciences
Impact factor: 6.133, year: 2020
Method of publishing: Open access
https://acp.copernicus.org/articles/20/11161/2020/

In situ CO2 and CO measurements from five atmospheric ICOS (Integrated Carbon Observation System) stations have been analysed together with footprint model runs from the regional transport model STILT, to develop a dedicated strategy for flask sampling with an automated sampler. Flask sampling in ICOS has three different purposes: (1) Provide an independent quality control for in situ observations, (2) provide representative information on atmospheric components currently not monitored in situ at the stations, (3) collect samples for 14CO2 analysis that are significantly influenced by fossil fuel CO2 (ffCO2) emission areas. Based on the existing data and experimental results obtained at the Heidelberg pilot station with a prototype flask sampler, we suggest that single flask samples should be collected regularly every third day around noon/afternoon from the highest level of a tower station. Air samples shall be collected over one hour with equal temporal weighting to obtain a true hourly mean. At all stations studied, more than 50 % of flasks to be collected around mid-day will likely be sampled during low ambient variability (< 0.5 ppm standard deviation of one-minute values). Based on a first application at the Hohenpeißenberg ICOS site, such flask data are principally suitable to detect CO2 concentration biases larger than 0.1 ppm with a one-sigma confidence level between flask and in situ observations from only 5 flask comparisons. In order to have a maximum chance to also sample ffCO2 emission areas, additional flasks need to be collected on all other days in the afternoon. Using the continuous in situ CO observations, the CO deviation from an estimated background value must be determined the day after each flask sampling and, depending on this offset, an automated decision must be made if a flask shall be retained for 14CO2 analysis.
Permanent Link: http://hdl.handle.net/11104/0311616