TY - JOUR A1 - Rigg, Y. J. A1 - Alpert, P. A. A1 - Knopf, D. A. T1 - Immersion freezing of water and aqueous ammonium sulphate droplets initiated by Humic Like Substances as a function of water activity JO - Atmos. Chem. Phys. Discuss. J1 - ACPD VL - 2013 SP - 4917 EP - 4961 Y1 - 2013/02/20 PB - Copernicus Publications SN - 1680-7375 UR - https://acp.copernicus.org/preprints/13/4917/2013/ L1 - https://acp.copernicus.org/preprints/13/4917/2013/acpd-13-4917-2013.pdf DO - 10.5194/acpd-13-4917-2013 ER -