Long-term observations. The long-term measurement campaign has been launched at the background Fonovaya station in the West Siberia, located ca 70 km to the south-west from Tomsk. The measurements with two instruments, Particle Size Magnifier (PSM) and Neutral cluster and Air Ion Spectrometer (NAIS) started in July 2019 and continue to present time (note, however, that we do not have access to the data from on-going measurements since 02.2022 till at least 31.12.2022). Two instruments, Differential Particle Mobility Sizer (DMPS) and CI-APi-TOF were sent to Siberia for a shorter campaign, which lasted for 1.5 years: March 2020 - November 2021.
Integrated analysis of GTP in pristine environments. In order to understand NPF/GTPs at Fonovaya, we have analysed the new data set from spring 2020 when DMPS and APi-TOF were installed at the station. We used the data from all four new aerosol instruments that were deployed in the station. The main results can be summarized as follows. Spring 2020 was unusually warm, with spring temperatures exceeding normal temperatures by 3-6 degrees. Based on APi-TOF data analysis, we concluded that spring could be separated into two periods: early spring (March-mid April), when mass spectra contained abundant sulfuric acid clusters and up to 10% of sulfuric acid-ammonia clusters, and late spring (mid April-May), when in addition to abundant sulfuric acid clusters, the spectra contained an increased amount of heavy organic molecules. These two periods were roughly separated by the date of snowmelt. During early spring 2020, we observed an unexpectedly high number of NPF, on ca 50% of all days.
We have established a new station in Beijing and conducted there observations since January 2018. In that way we have been able to conduct comprehensive observation in a real megacity and e.g. find out the importance of new particle formation. Furthermore we have observed that the growth rate of the freshly formed aerosol particles is in practice, relatively constant given the significance on formation rate. Moreover, we have continued the study of gas-to-particle in polluted environments and made breakthroughs in the mechanistic understanding of this process,
Clouds play an important role in the COBACC feedback loop. During the latest working period, we investigated the interactions of boreal forest with air masses in order to understand how the properties of air masses are transformed over the forest and how the transformation influences the formation of clouds and precipitation. We show that when the air mass comes from the clean sector (polar sea), the transformation of the air mass from marine to continental one happens on the time scale of 60 h. During these 60 h, the number of cloud condensation nuclei and the absolute humidity in the air mass are constantly growing. There is also an increase in the median cloud optical thickness and cloud water path, as well as precipitation. Our results suggest that boreal forest can effectively interact with the boundary layer influencing cloud formation and precipitation.
We have performed several laboratory experiments at the CLOUD (Cosmic Leaving OUtdoor Droplets) chamber at CERN, Switzerland and found out and confirmed several processes like the interplay of sulphuric acid, amines, ammonia and extreme low volatile organics on clustering, nucleation and subsequent growth. Actually, the hypothesis on size dependent growth rate of freshly formed aerosol particles are further confirmed. In addition, we studied the effect of temperature on the pure biogenic new particle formation from alpha-pinene, simulating pristine, pre-industrial times.
