Ice nucleating particles around the world – the attempt of an overview

Ice nucleating particles (INPs) have gained much renewed attention in the last decade. While there was much interest in laboratory studies at first, this has, by now, switched to examining INPs in the Earth’s atmosphere. In this presentation a short overview will be given over new knowledge gained on atmospheric INPs, based on measurement studies done by the TROPOS cloud group with many co-operators in a number of studies and on many results published in literature. The topics that will be touched are the following:

- A number of times, a large fraction of INPs was found to be supermicron in size [4,7,11,12,20].

- Biogenic INPs that are ice active at ~ > -20°C are frequently detected [5,10,11,15,18].

- Concentrations of INP (N_INP) over or close to land are generally larger than those in remote marine regions as e.g., the Southern Ocean or the North East Atlantic, and the contribution to INPs from sea spray might generally be minor except for in these remote marine regions [7,13,14,19,22]; however, for specific conditions observations of elevated N_INP likely originating from sea spray were also made [6,9,11].

- From Arctic ice cores covering the time from 1479 to 1998, no changing trends in N_INP were found [8]; concerning short term fluctuations, in the Arctic, a number of studies found an increase in N_INP during spring time [1,2,4,21], and even an annual cycle has been described [23]. Generally, with continuous warming of the Earth also changes in INP in the Arctic might influence the warming observed there .

- Anthropogenic pollution was reported not to contribute INPs active in the temperature range down to -25°C [3,16,24], while still conflicting results exist concerning INPs from ship exhaust [17,22].

The literature list given here is not (and cannot be) exhaustive. This contribution is understood as an attempt of an overview on the state of the art concerning atmospheric INP and is also thought to induce discussions on what we already have understood and where there are still open questions.

Literature:

[1] Bigg & Leck (2001), Cloud-active particles over the central Arctic Ocean, J. Geophys. Res.-Atmos., 106, 32155-32166, doi:10.1029/1999jd901152.

[2] Borys (1983), The effects of long-range transport of air pollutants on Arctic cloud-active aerosol, Colo. State Univ., Ft. Collins, CO.

[3] Chen et al. (2018), Ice nucleating particle concentrations unaffected by urban air pollution in Beijing, China, Atmos. Chem. Phys., 18, 3523–3539, doi:10.5194/acp-18-3523-2018.

[4] Creamean et al. (2018), Marine and terrestrial influences on ice nucleating particles during continuous springtime measurements in an Arctic oilfield location, Atmos. Chem. Phys., 18, 18023–18042, doi:10.5194/acp-18-18023-2018.

[5] Creamean et al. (2019), Using spectra characteristics to identify ice-nucleating particle populations during the winter in the Alps, Atmos. Chem. Phys., 19, 8123–8140, doi:10.5194/acp-19-8123-2019.

[6] Creamean et al. (2019), Ice nucleating particles carried from below a phytoplankton bloom to the Arctic atmosphere, Geophys. Res. Lett., accepted.

[7] Gong et al. (2019), Characterization of aerosol particles at Cape Verde close to sea and cloud level heights - Part 2: ice nucleating particles in air, cloud and seawater, in preparation.

[8] Hartmann et al. (2019), Variation of ice nucleating particles in the European Arctic over the last centuries, Geophys. Res. Lett., 46, doi:10.1029/2019GL082311.

[9] Hartmann et al. (2019), High temperature INP on airborne filter samples linked to the presence of open leads in the Arctic, in preparation.

[10] Hill et al. (2016), Sources of organic ice nucleating particles in soils, Atmos. Chem. Phys., 16(11), 7195-7211, doi:10.5194/acp-16-7195-2016.

[11] Ladino et al. (2019), Ice-nucleating particles in a coastal tropical site, Atmos. Chem. Phys., 19, 6147–6165, 10.5194/acp-19-6147-2019.

[12] Mason et al. (2016), Size-resolved measurements of ice-nucleating particles at six locations in North America and one in Europe, Atmos. Chem. Phys., 16(3), 1637-1651, doi:10.5194/acp-16-1637-2016.

[13] McCluskey et al. (2018), Observations of Ice Nucleating Particles Over Southern Ocean Waters, Geophys. Res. Lett., 45(21), 11989-11997, doi:10.1029/2018gl079981.

[14] McCluskey et al. (2018), Marine and Terrestrial Organic Ice-Nucleating Particles in Pristine Marine to Continentally Influenced Northeast Atlantic Air Masses, J. Geophys. Res.-Atmos., 123(11), 6196-6212, doi:10.1029/2017jd028033.

[15] O'Sullivan et al. (2018), Contributions of biogenic material to the atmospheric ice-nucleating particle population in North Western Europe, Scientific Reports, 8, doi:10.1038/s41598-018-31981-7.

[16] Tan et al. (2018), The study of atmospheric ice‑nucleating particles via microfluidically generated droplets, Microfluidics and Nanofluidics, doi.org/10.1007/s10404-018-2069-x.

[17] Thomson et al. (2018), Intensification of ice nucleation observed in ocean ship emissions, Scientific Reports, 8, doi:10.1038/s41598-018-19297-y.

[18] Šantl-Temkiv et al. (2019), Biogenic sources of Ice Nucleation Particles at the high arctic site Villum Research Station, Environ. Sci. Technol., accepted.

[19] Schmale et al. (2019) Overview of the Antarctic Circumnavigation Expedition: Study of Preindustrial-like Aerosols and Their Climate Effects (ACE-SPACE), BAMS, accepted.

[20] Si et al. (2018), Ice-nucleating ability of aerosol particles and possible sources at three coastal marine sites, Atmos. Chem. Phys., 18, 15669-15685, doi:10.5194/acp-18-15669-2018.

[21] Tobo et al. (2019), Glacially sourced dust as a potentially significant source of ice nucleating particles, 12, 253+, Nat. Geosci., doi:10.1038/s41561-019-0314-x.

[22] Welti et al., Ship based measurements of ice nuclei concentrations over the Arctic, Atlantic and Southern Ocean., in preparation.

[23] Wex et al. (2019), Annual variability of ice nucleating particle concentrations at different Arctic locations, Atmos. Chem. Phys., 19, 5293–5311, 10.5194/acp-19-5293-2019.

[24] Yadav et al., (2018), Ice nucleating particle properties relevant to aerosol cloud interactions in the Himalayan Region, Internat. Aerosol Conf., St. Louis.