Chasing preindustrial aerosols at Izaña, Tenerife
Since the end of March, a group of scientists from INAR have been investigating trace gases, aerosols and new particle formation in Izaña, Tenerife. The clean air of such environment makes Izaña a perfect site to study preindustrial atmosphere conditions.

Since the end of March, a group of scientists from Helsinki University is in charge of the Chasing preindustrial aerosols campaign at the Izaña Atmospheric Observatory (IZO; 2373 m a.s.l.), which is located on the island of Tenerife, Canary Islands, Spain.

The aim of this campaign is to understand the gas precursors responsible for new particle formation (NPF) process in pristine environment.  IZO station is far away from any significant industrial activities and so free of local anthropogenic influences. The clean air and pristine skies offer excellent conditions for in-situ measurements of trace gases, aerosols and pristine NPF observations.

A suite of instrumentations have been installed and handled by Federico Bianchi, Wei Huang, Jiali Shen, Diego Aliaga, Myriam Agró and Magdalena Okuljar. A Vocus-PTR-TOF was used to measure VOC (volatile organic compounds) and oxidation products of DMS (dimethyl sulphide). An APi-TOF equipped with a MION inlet was used to detect ion clusters (using API mode), less oxygenated VOC (using Br- as the reagent ion), and sulphuric acid (H2SO4) and more oxygenated VOC (including highly oxygenated organic molecules, HOM; using NO3– as the reagent ion). A NAIS and a PSM was deployed for number concentration and size distribution of atmospheric ions and neutral particles with a mobility diameter of 0.8-42 nm and number concentration of particle with a mobilitiy diameter of 1.25-2.5 nm, respectively.

With the above mentioned instrumentation installed at this pristine site from us, together with the instrumentation already at IZO including trace gas sensors (e.g., SO2, O3, and NOx), particle number and size distribution and black carbon measurements (e.g., CPC, SMPS, APS, and Aethalometer), we would like to answer the following scientific questions.

  1. What is the mechanism driving NPF there?
  2. What are the concentrations of gas precursors forming clusters (H2SO4, HOMs, oxidation products of DMS)?
  3. What is the chemical composition of clusters at Izaña and which compounds drive their growth to larger sizes?

The campaign is a TNA (TransNational Access) Observation campaign, under the umbrella of the ATMO-ACCESS project (Sustainable Access to Atmospheric Research Facilities, more info, supported by the H2020 European Research Council (grant no. 850614, 101008004).

Many thanks to the ISAF (Izaña Subtropical Access Facility), as an infrastructure that offers TNA-Observation and TNA-Calibration, who gives a lot of support on practicalities (such help on customs management, accommodation, meteorological warnings to severe weather, etc.) and scientific-technical support, as auxiliary data from their own programmes (trace gases, aerosols, radiation, meteorology, etc.). The IARC aerosol group, led from the head of the programme, África Barreto, and with the support of the other IARC staff, have been helping on instrument installations and other requirements from our side.