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

• Published in: Atmospheric research Vol. 259; p. 105693
• Main Authors: Wagh, Sandeep, Singh, Prayagraj, Ghude, Sachin D., Safai, Pramod, Prabhakaran, Thara, Kumar, P. Pradeep
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2021
• Subjects: Black carbon; Cloud chamber; Fog-Haze; Ice Nucleating Particles; Cloud chamber; Black carbon; Ice Nucleating Particles; Fog-Haze
• ISSN: 0169-8095; 1873-2895
• DOI: 10.1016/j.atmosres.2021.105693

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 < 0.001) was observed between INPs and BC under foggy conditions for January 2017 period. The activation fraction was ranges from 1:106 to 1:108 for the entire campaign. Scanning electron microscopy analyses revealed that particles chemistry was diverse, and particles were a mixture of BC, mineral dust, and soot. The enrichment factor indicates that elements like Nitrogen, Sulphur, and Chloride were of anthropogenic origin. •Measurements of the ice nucleating particles (INPs) were carried out under heavily polluted urban environment and fog-haze conditions.•No correlation was observed between INPs (L−1) with particles of size greater than > 0.5 μm and Particulate Matter.•A significant and positive correlation was observed between BC and INPs during foggy meteorological condition.•The ANOVA statistical test shows that the average concentration of INP (L−1) was significantly different under different meteorological conditions.