EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Global observation of iodic acid (HIO3)

Xucheng He1, Tuija Jokinen1, Nina Sarnela1, Lisa Beck1, Heikki Junninen2, Matti Rissanen3, Wei Nie4, Chao Yan1, Deniz Kemppainen1, Douglas Worsnop1, Mikko Sipilä1, and Markku Kulmala1
Xucheng He et al.
  • 1University of Helsinki, Physics, Finland (
  • 2Institute of Physics, University of Tartu
  • 3Aerosol physics laboratory, Physics unit, Tampere University, Tampere, Finland
  • 4Joint International Research Laboratory of Atmospheric and Earth System Sciences, School of Atmospheric Sciences, Nanjing University, Nanjing, Jiangsu Province, China

Trace iodine vapours have a significant impact on atmospheric chemistry, influencing catalytic ozone destruction and the HOx / NOx cycles. Oxidized iodine species also form aerosols in coastal and polar regions (O’Dowd et al, 2002), playing a direct role in Earth’s radiation balance. It was recently shown that iodic acid (HIO3) has a significant impact on coastal new particle formation processes (Sipilä et al., 2016). However, neutral HIO3 molecules have only been measured in two sites (Sipilä et al., 2016).

In this study, a global observation of HIO3 has been carried out in ten sites around the globe, including city sites, Arctic and Antarctica sites, a remote island site, a coastal site and a boreal forest site. While the existence of HIO3 is unambiguously revealed in all of the sites, its concentration varies significantly among them. Dedicated laboratory experiments are required to examine the particle formation rates from iodine-containing species to be able to predict their global importance in particle formation, and further, in cloud condensation nuclei formation.


O’Dowd, C. D. et al. Marine aerosol formation from biogenic iodine emissions. Nature 417, 632–6 (2002)

Sipilä, M. et al. Molecular-scale evidence of aerosol particle formation via sequential addition of HIO3. Nature 537, 532–534 (2016).


How to cite: He, X., Jokinen, T., Sarnela, N., Beck, L., Junninen, H., Rissanen, M., Nie, W., Yan, C., Kemppainen, D., Worsnop, D., Sipilä, M., and Kulmala, M.: Global observation of iodic acid (HIO3), EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-19391,, 2020


Display file

Comments on the display

AC: Author Comment | CC: Community Comment | Report abuse

displays version 1 – uploaded on 04 May 2020, no comments