Periodic Reporting for period 4 - ATM-GTP (Atmospheric Gas-to-Particle conversion)
Période du rapport: 2021-12-01 au 2022-05-31
Atmospheric Gas-to-Particle conversion (ATM-GTP) is a 5-year project focusing on one of the most critical atmospheric processes relevant to global climate and air quality. It is especially focused on the first steps of atmospheric aerosol particle formation and growth. The project concentrates on the currently lacking environmentally-specific knowledge associated with atmospheric aerosols, the nano-scale gas-to-particle conversion (GTP). The main scientific objective of ATM-GTP is to create a deep understanding on atmospheric GTP taking place at the sub-5 nm size range. The project is carrying out atmospheric measurements in heavily-polluted Chinese mega cities like Beijing and in pristine environments like Siberia and Nordic high-latitude regions. We also aim to find out how nano-GTM is associated with air quality-climate interactions and feedbacks. We are interested in quantifying the effect of nano-GTP on the COBACC (Continental Biosphere-Aerosol-Cloud-Climate) feedback loop that is important in Arctic and boreal regions. The project uses data from novel ground based stations including SMEAR (Stations Measuring Ecosystem Atmospheric Relations) stations, related modelling platforms and regional data from Russia and China.
The overlying scientific objective of ATM-GTP is to attain a deep understanding of atmospheric gas-to-particle conversion occurring in the sub-5 nm size range (nano-GTP), and to determine how nano-GTP is associated with air quality-climate interactions and feedbacks. The specific objectives are:
1. To quantify the contribution to nano-GTP from key neutral and ion-mediated processes (production of gaseous precursors, atmospheric oxidation, clustering, initial steps of cluster/aerosol growth, boosting growth / activation of clusters by of multiple vapors).
2. To quantify the non-linear physical and chemical atmospheric processes affecting and interacting with nano-GTP in heavily-polluted environments.
3. To quantify the non-linear processes governing nano-GTP in pristine environments like Siberia and Arctic areas.
4. To quantify the effects of biogenic and anthropogenic emissions on nano-GTP, their interactions, and their relative contributions to global aerosol number loads in present-day and future climates.
5. To quantify the effect of nano-GTP on the COBACC (COntinental Biosphere-Aerosol-Cloud-Climate) feedback loop.
Via producing new secondary aerosol particles, nano-GTP affects local, regional and global aerosol loadings and alters aerosol size distributions and Cloud Condensation Nuclei (CCN) concentrations. In polluted conditions the main concern is air quality, whereas in pristine conditions the interest lies more in the changing climate.
During the ATM-GTP we have been able to show that gas-to-particle conversion produced majority of aerosol number and aerosol mass. Over 2/3 of number in Beijing and over 4/5 of mass in Beijing and the same order of magnitude in Siberia.
The overlying scientific objective of ATM-GTP is to attain a deep understanding of atmospheric gas-to-particle conversion occurring in the sub-5 nm size range (nano-GTP), and to determine how nano-GTP is associated with air quality-climate interactions and feedbacks. The specific objectives are:
1. To quantify the contribution to nano-GTP from key neutral and ion-mediated processes (production of gaseous precursors, atmospheric oxidation, clustering, initial steps of cluster/aerosol growth, boosting growth / activation of clusters by of multiple vapors).
2. To quantify the non-linear physical and chemical atmospheric processes affecting and interacting with nano-GTP in heavily-polluted environments.
3. To quantify the non-linear processes governing nano-GTP in pristine environments like Siberia and Arctic areas.
4. To quantify the effects of biogenic and anthropogenic emissions on nano-GTP, their interactions, and their relative contributions to global aerosol number loads in present-day and future climates.
5. To quantify the effect of nano-GTP on the COBACC (COntinental Biosphere-Aerosol-Cloud-Climate) feedback loop.
Via producing new secondary aerosol particles, nano-GTP affects local, regional and global aerosol loadings and alters aerosol size distributions and Cloud Condensation Nuclei (CCN) concentrations. In polluted conditions the main concern is air quality, whereas in pristine conditions the interest lies more in the changing climate.
During the ATM-GTP we have been able to show that gas-to-particle conversion produced majority of aerosol number and aerosol mass. Over 2/3 of number in Beijing and over 4/5 of mass in Beijing and the same order of magnitude in Siberia.
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.
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.
the main results beyond the state of the art are
1) the major fraction of haze particles are secondary (made via atmospheric processes) origin: over 85% of mass and over 2/3 of the number concentration.
2) The new particle formation is more rare in Siberia than theoretically predicted.
The most important achievement and actually changing the whole view points that growth rate of nucleation mode aerosol particles is pretty constant and preety similar all over the world. This finding will change the present thinking on which aerosol processe are the most crucial. This finding was based on the whole 5 years work and published just before the project was ending.
1) the major fraction of haze particles are secondary (made via atmospheric processes) origin: over 85% of mass and over 2/3 of the number concentration.
2) The new particle formation is more rare in Siberia than theoretically predicted.
The most important achievement and actually changing the whole view points that growth rate of nucleation mode aerosol particles is pretty constant and preety similar all over the world. This finding will change the present thinking on which aerosol processe are the most crucial. This finding was based on the whole 5 years work and published just before the project was ending.