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Atmospheric ions and new particle formation events at a tropical location, Pune, India

Kamra, A. K.; Siingh, Devendraa; Gautam, A. S.; Kanawade, Vijay LU ; Tripathi, S. N. and Srivastava, A. K. (2015) In Quarterly Journal of the Royal Meteorological Society 141(693). p.3140-3156
Abstract
Characteristics of small, intermediate and large ions and nanometre particles, and the influences of environmental conditions and local topography on the interactions of these ions and particles in the size range of 3.85-47.8 nm diameter are studied during new particle formation (NPF) events observed at Pune, India from 20 March to 23 May 2012. During the NPF events, the formation rate of 5 nm particles ranged from 3.5 to 13.9 cm(-3) s(-1)and growth rates of both positive and negative ions were greater than those of neutral particles. Total ion concentrations in this size range were approximately double on event days than on non-event days. The NPF events were generally preceded by 2-3 h periods of enhanced concentration of ions and... (More)
Characteristics of small, intermediate and large ions and nanometre particles, and the influences of environmental conditions and local topography on the interactions of these ions and particles in the size range of 3.85-47.8 nm diameter are studied during new particle formation (NPF) events observed at Pune, India from 20 March to 23 May 2012. During the NPF events, the formation rate of 5 nm particles ranged from 3.5 to 13.9 cm(-3) s(-1)and growth rates of both positive and negative ions were greater than those of neutral particles. Total ion concentrations in this size range were approximately double on event days than on non-event days. The NPF events were generally preceded by 2-3 h periods of enhanced concentration of ions and aerosols (PECIA) which are associated with katabatic winds from the surrounding hill-slopes at our site. During PECIA, ions 8 nm diameter grew faster and attained mode diameters greater than those of neutral particles. PECIA provided the ions of sub-8 nm diameter and dramatically reduced the condensation sinks and thus contributed to the development of conditions conducive for NPF. During PECIA, total concentrations of the ions and particles become almost equal and the Boltzmann charge distribution breaks down. During NPF events, mode diameters of the ions and particles first steeply decreased accompanied by a steep increase in condensation sink but later gradually increased at identical rates. Observations of charging ratio of 3-4 nm particles being higher than the charge equilibrium value and non-observation of charge equilibrium for >5 nm ions and particles indicate occurrence of ion nucleation and/or advection during the PECIA. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
new particle formation, ion nucleation, ions, aerosols
in
Quarterly Journal of the Royal Meteorological Society
volume
141
issue
693
pages
3140 - 3156
publisher
Royal Meteorological Society
external identifiers
  • wos:000366860500018
  • scopus:84952298805
ISSN
0035-9009
DOI
10.1002/qj.2598
language
English
LU publication?
yes
id
85b4fcd8-56bf-43af-bde4-95f6ac7fc195 (old id 8556653)
date added to LUP
2016-01-26 15:08:23
date last changed
2017-08-20 03:14:22
@article{85b4fcd8-56bf-43af-bde4-95f6ac7fc195,
  abstract     = {Characteristics of small, intermediate and large ions and nanometre particles, and the influences of environmental conditions and local topography on the interactions of these ions and particles in the size range of 3.85-47.8 nm diameter are studied during new particle formation (NPF) events observed at Pune, India from 20 March to 23 May 2012. During the NPF events, the formation rate of 5 nm particles ranged from 3.5 to 13.9 cm(-3) s(-1)and growth rates of both positive and negative ions were greater than those of neutral particles. Total ion concentrations in this size range were approximately double on event days than on non-event days. The NPF events were generally preceded by 2-3 h periods of enhanced concentration of ions and aerosols (PECIA) which are associated with katabatic winds from the surrounding hill-slopes at our site. During PECIA, ions 8 nm diameter grew faster and attained mode diameters greater than those of neutral particles. PECIA provided the ions of sub-8 nm diameter and dramatically reduced the condensation sinks and thus contributed to the development of conditions conducive for NPF. During PECIA, total concentrations of the ions and particles become almost equal and the Boltzmann charge distribution breaks down. During NPF events, mode diameters of the ions and particles first steeply decreased accompanied by a steep increase in condensation sink but later gradually increased at identical rates. Observations of charging ratio of 3-4 nm particles being higher than the charge equilibrium value and non-observation of charge equilibrium for >5 nm ions and particles indicate occurrence of ion nucleation and/or advection during the PECIA.},
  author       = {Kamra, A. K. and Siingh, Devendraa and Gautam, A. S. and Kanawade, Vijay and Tripathi, S. N. and Srivastava, A. K.},
  issn         = {0035-9009},
  keyword      = {new particle formation,ion nucleation,ions,aerosols},
  language     = {eng},
  number       = {693},
  pages        = {3140--3156},
  publisher    = {Royal Meteorological Society},
  series       = {Quarterly Journal of the Royal Meteorological Society},
  title        = {Atmospheric ions and new particle formation events at a tropical location, Pune, India},
  url          = {http://dx.doi.org/10.1002/qj.2598},
  volume       = {141},
  year         = {2015},
}