Study of ice nucleating particles in fog-haze weather at New Delhi, India: A case of polluted environment

Abstract Ice nucleating particles (INPs) concentration in deposition mode was measured and reported for a polluted urban site in New Delhi, India. The measurements were carried out during the winter period from December 2016 to January 2017. The INPs data, sampled under different meteorological conditions, were analysed using a thermal gradient static diffusion chamber. The observed INPs concentration ranges from 0.05 to 9.55 L−1 at mean nucleation temperature − 18.49 °C (SD = 0.27 °C). The mean INPs number concentration observed under three meteorological conditions was significantly different. No correlation was observed between particles size >0.5 μm, Particulate Matter and BC for the entire observation period, but correlation (r2 = 0.27, p