Atmospheric New Particle Formation in Po Valley, Italy, one of most polluted regions in Europe!

Currently in Po Valley, one of the most polluted areas in Europe, there is a group of scientists from several European institutes working hard in order to understand how particles are formed in such area. The location, project, and equipment are unique. Since the end of February 2022, after an intense instrumental setup period, they are now fully operational.

In February 2022, researcher from INAR (Institute for Atmospheric and Earth System Research of the University of Helsinki) started field measurements in San Pietro Capofiume, Italy, in collaboration with CNR-ISAC (Institute of Atmospheric Sciences and Climate, University of Bologne), ACES (Department of Environmental Science, Stockholm University), and other European Universities such as the EPFL of Lausanne and the University of Patras.

The measurement campaign is conducted at the meteorological station “Giorgio Fea”, located at the rural site of San Pietro Capofiume, in the Emilia Romagna region, Italy (43°21’ N, 12°34’ E, 11 m asl), which is in the heart of the Po Valley in Northern Italy. The Po Valley is considered one of the most polluted areas of Europe due to huge industrial and agricultural activities in this densely populated area. Furthermore, the meteorological situation often traps the pollutants in the basin surrounded by mountains, the Alps on the North and on the West, Apennine on the South. For the first time, the researchers will deploy advanced instruments in this area for measuring fog and new particle formation at the same time, hopefully providing deeper insights into the mechanism of the pollution that happens here.

Atmospheric new particle formation (NPF) is a dominant source of atmospheric ultrafine articles, which strongly influence climate and human health. However, the actual role and mechanism of NPF may vary significantly from location to location and are largely unclear in urban and polluted environments, which motivates us to conduct this field campaign. We aim to investigate what triggers and facilitates atmospheric NPF in Po Valley and how it is linked to the air quality. In addition to the permanent measurements at the station, we have deployed two APi-TOF (atmospheric pressure interface time-of-flight) mass spectrometers (one equipped with chemical ionization inlet for the measurement of neutral gaseous compounds and one detecting naturally charged molecular clusters, the first steps of NPF). Particle counters and state-of-the-art size-distribution measurements are also deployed at the site for the measurement of concentrations of aerosol particles of different sizes, which allows us to determine the rates at which new particles are formed and subsequently grow to larger sizes during NPF. 

The two APi-TOFs at the sampling site were set up in the measurement container after one week of work by Federico Bianchi, Jing Cai and Yifang Gu, meanwhile the size-distribution measurements were installed and run by Dominik Stolzenburg, Sebastian Ho. Our researchers need to calibrate and maintain the APi-TOFs and particle counting systems occasionally and to ensure that all the set-up instruments are working correctly during the campaign.

After a few days of observation, all the instruments were performing great and we are now successfully sampling fog and aerosols in our measurement sites. Several NPF events have already been captured and the preliminary results showed these events with regional characteristics. With the measurement results from this field campaign, we are planning to:

  1. Identify the mechanism driving NPF in Po Valley.
  2. Capture the key species that drive the growth of particles.
  3. Compare the mechanism of NPF and particle growth in places from different areas, such as Po Valley, Italy, and Beijing, China to obtain an idea on how future emission reductions in highly polluted megacities will influence NPF.

“A great campaign in Po Valley in North Italy measuring Fog and New Particle Formation with instruments that have never been used here. Such campaign can have only one name: FAIRARI” says Federico Bianchi.

Finally, take a look at our Po valley campaign team having a well-deserved dinner.