EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Characterization of particle number size distributions and new particle formation in different Indian locations

Mathew Sebastian1, Sobhan Kumar Kompalli2, Anil Kumar3, Sandhya Jose4,5, S. Suresh Babu2, Govindan Pandithurai3, Sachchidanand Singh4,5, Rakesh K. Hooda6, Vijay K. Soni7, Jeffrey R. Pierce8, Ville Vakkari6,9, Eija Asmi6, Daniel M. Westervelt10,11, Antii-P Hyvarinen6, and Vijay P. Kanawade1
Mathew Sebastian et al.
  • 1Center for Earth Ocean and Atmospheric Sciences, Center for Earth Ocean and Atmospheric Sciences, University of Hyderabad, HYDERABAD, India
  • 2Space Physics Laboratory, Vikram Sarabhai Space Centre, Thiruvananthapuram, India
  • 3Indian Institute of Tropical Meteorology, Ministry of Earth Sciences, Pune, India
  • 4CSIR-National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi, India
  • 5Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
  • 6Finnish Meteorological Institute, Erik Palmenin Aukio 1, Helsinki, Finland
  • 7India Meteorological Department, Ministry of Earth Sciences, New Delhi, India
  • 8Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA
  • 9Atmospheric Chemistry Research Group, Chemical Resource Beneficiation, North-West University, Potchefstroom, South Africa
  • 10Lamont-Doherty Earth Observatory of Columbia University, New York, USA
  • 11NASA Goddard Institute for Space Studies, New York, NY, USA

Particle number size distribution has critical importance in characterizing the number, size, surface area, volume, and evolution of aerosols in the atmosphere. Atmospheric new particle formation (NPF) is one the largest source of aerosol numbers to the terrestrial atmosphere and greatly impact the evolution of particle number size distribution. Here, we analyzed at least one year of asynchronous measurements of particle number size distributions from six different locations in India. We found that NPF frequently occurs at all locations in the pre-monsoon season (March through May) and is the least common in the post-monsoon season (October-November).   Considering all sites (mountain background, mountain semi-rural, coastal semi-urban and urban), the particle formation rate of lowest detectable size (JLDS) varied by more than an order of magnitude (0.01 - 0.6 cm-3 s-1) and the growth rate between the lowest detectable size and 25 nm (GRLDS-25nm) by about three orders of magnitude (0.2 - 17.2 nm h-1). The site-specific JLDS and GRLDS-25nm are positively correlated, indicating their co-dependence on gas-phase production rates of low-volatility vapors, driven by the source and atmospheric conditions. Our results also showed that NPF events significantly modulate the shape of particle number size distributions, particularly in the pre-monsoon season. The NPF-associated CCN concentrations were higher in urban locations than the mountain background sites. Although using asynchronous measurements, our results implicate the process-level characterization of particle number size distribution.

How to cite: Sebastian, M., Kumar Kompalli, S., Kumar, A., Jose, S., Babu, S. S., Pandithurai, G., Singh, S., K. Hooda, R., K. Soni, V., R. Pierce, J., Vakkari, V., Asmi, E., M. Westervelt, D., Hyvarinen, A.-P., and P. Kanawade, V.: Characterization of particle number size distributions and new particle formation in different Indian locations, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11254,, 2022.