In:
Atmospheric Chemistry and Physics, Copernicus GmbH, Vol. 22, No. 7 ( 2022-04-07), p. 4491-4508
Abstract:
Abstract. Atmospheric new particle formation (NPF) is a crucial
process driving aerosol number concentrations in the atmosphere; it can
significantly impact the evolution of atmospheric aerosol and cloud
processes. This study analyses at least 1 year of asynchronous particle
number size distributions from six different locations in India. We also
analyze the frequency of NPF and its contribution to cloud condensation
nuclei (CCN) concentrations. We found that the NPF frequency has a
considerable seasonal variability. At the measurement sites analyzed in this
study, NPF frequently occurs in March–May (pre-monsoon, about 21 % of the
days) and is the least common in October–November (post-monsoon, about 7 %
of the days). Considering the NPF events in all locations, the particle
formation rate (JSDS) varied by more than 2 orders of magnitude
(0.001–0.6 cm−3 s−1) and the growth rate between the smallest
detectable size and 25 nm (GRSDS-25 nm) by about 3 orders of
magnitude (0.2–17.2 nm h−1). We found that JSDS was higher by
nearly 1 order of magnitude during NPF events in urban areas than mountain
sites. GRSDS did not show a systematic difference. Our results showed
that NPF events could significantly modulate the shape of particle number
size distributions and CCN concentrations in India. The contribution of a
given NPF event to CCN concentrations was the highest in urban locations
(4.3 × 103 cm−3 per event and 1.2 × 103
cm−3 per event for 50 and 100 nm, respectively) as compared to
mountain background sites (2.7 × 103 cm−3 per event and
1.0 × 103 cm−3 per event, respectively). We emphasize that
the physical and chemical pathways responsible for NPF and factors that
control its contribution to CCN production require in situ field
observations using recent advances in aerosol and its precursor gaseous
measurement techniques.
Type of Medium:
Online Resource
ISSN:
1680-7324
DOI:
10.5194/acp-22-4491-2022
DOI:
10.5194/acp-22-4491-2022-supplement
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2022
detail.hit.zdb_id:
2092549-9
detail.hit.zdb_id:
2069847-1
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