Observations of particle number size distributions and new particle formation in six Indian locations

Abstract. Atmospheric new particle formation (NPF) is a crucial process driving aerosol number concentrations in the atmosphere; it can significantly impact evolution of atmospheric and cloud processes. This study analyses at least 1 year asynchronous size distributions from six different locations India. We also analyze frequency NPF its contribution to condensation nuclei (CCN) concentrations. found that has considerable seasonal variability. At measurement sites analyzed this study, frequently occurs March–May (pre-monsoon, about 21 % days) common October–November (post-monsoon, 7 days). Considering events all locations, rate (JSDS) varied by more than 2 orders magnitude (0.001–0.6 cm−3 s−1) growth between smallest detectable 25 nm (GRSDS-25 nm) 3 (0.2–17.2 h−1). JSDS was higher nearly order during urban areas mountain sites. GRSDS did not show systematic difference. Our results showed could modulate shape CCN The given event highest (4.3 × 103 per 1.2 for 50 100 nm, respectively) as compared background (2.7 1.0 event, respectively). emphasize physical chemical pathways responsible factors control production require situ field observations using recent advances precursor gaseous techniques.