Novel, optimized and compact gas handling system for the HUN tall tower ICOS station

  The main goal of ICOS Hungary was to expand the geographical coverage of the ICOS network towards Eastern Europe. As Hungary is located in the zone of westerlies winds in Europe, adding measurement stations East of the existing ICOS network may significantly reduce the uncertainty of the continental atmospheric CO2 and CH4 budget models. Since the joining of HUN it is (almost) the easternmost ICOS atmospheric background station. ICOS has high expectations for all the stations seeking to join the observation system. These expectations include ensuring the highest quality and employing state-of-the-art equipment available in the stations. Atmospheric stations wishing to connect to the network has to develop their gas handling systems themselves. This requirement places additional responsibility on the operators of stations to create their own systems, allowing them to tailor gas handling processes to their unique needs and in accordance with ICOS network specifications. The gas handling system for the HUN station, was built in the collaboration between ATOMKI and Isotoptech Zrt., that has been developed for the possibility of commercial use also. This developed system has been operational in Hegyhatsal since the spring of 2022. The core of the system's is a Picarro analyzer (CO2, CH4 and H2O), that requires properly filtered and semidried air for operation. According to the expectations, the developed system meets all the ICOS requirements, including minimized response time, addressing memory effects, and ensuring appropriate flushing capacity. It operates in five independent sampling height (at HUN connected to elevations at 115m, 82m, 50m, 10m and a spare one) with a sampling rate of 10 l/min. Each line uses 2-micron filters before the Picarro, and one multiport VALCO rotary valve runs for efficient and precise environmental GHG gas analysis. For the purpose of ensuring analytical security, high-performance KNF inert pumps are employed for sample transfer/flushing in order to maintain the integrity and reliability of the analytical process. From 2022 the monitoring station continuously measures atmospheric concentrations of CO2, CH4, and other trace gases at the four sampling levels. The entire novel, compact gas handling equipment (made by Isotoptech) has stand-alone design, with a footprint of less than 1 m2, 2 m height, integrates all the components, and is designed for easy mobility. The gas handling system has undergone one year of routine operation with minimal maintenance requirements, proving to be reliable and consistently operational even while it is managed remotely from a distance of 500 km, without significant disruptions. Prepared with the professional support of the Doctoral Student Scholarship Program of the Cooperative Doctoral Program of the Ministry of Innovation and Technology financed from the National Research, Development and Innovation Fund and supported by the PARIS project (Grant Agreement No. 820846), which is funded by the European Commission through the Horizon 2020 research programme.