@article{fdi:010069317,
  title = {{CCN} production by new particle formation in the free troposphere},
  author = {{R}ose, {C}. and {S}ellegri, {K}. and {M}oreno, {I}. and {V}elarde, {F}. and {R}amonet, {M}. and {W}einhold, {K}. and {K}rejci, {R}. and {A}ndrade, {M}. and {W}iedensohler, {A}. and {G}inot, {P}atrick and {L}aj, {P}.},
  editor = {},
  language = {{ENG}},
  abstract = {{G}lobal models predict that new particle formation ({NPF}) is, in some environments, responsible for a substantial fraction of the total atmospheric particle number concentration and subsequently contributes significantly to cloud condensation nuclei ({CCN}) concentrations. {NPF} events were frequently observed at the highest atmospheric observatory in the world, on {C}hacaltaya (5240 m a.s.l.), {B}olivia. {T}he present study focuses on the impact of {NPF} on {CCN} population. {N}eutral cluster and {A}ir {I}on {S}pectrometer and mobility particle size spectrometer measurements were simultaneously used to follow the growth of particles from cluster sizes down to similar to 2 nm up to {CCN} threshold sizes set to 50, 80 and 100 nm. {U}sing measurements performed between 1 {J}anuary and 31 {D}ecember 2012, we found that 61% of the 94 analysed events showed a clear particle growth and significant enhancement of the {CCN}-relevant particle number concentration. {W}e evaluated the contribution of {NPF}, relative to the transport and growth of pre-existing particles, to {CCN} size. {T}he averaged production of 50 nm particles during those events was 5072, and 1481 cm(-3) for 100 nm particles, with a larger contribution of {NPF} compared to transport, especially during the wet season. {T}he data set was further segregated into boundary layer ({BL}) and free troposphere ({FT}) conditions at the site. {T}he {NPF} frequency of occurrence was higher in the {BL} (48 %) compared to the {FT} (39 %). {P}article condensational growth was more frequently observed for events initiated in the {FT}, but on average faster for those initiated in the {BL}, when the amount of condensable species was most probably larger. {A}s a result, the potential to form new {CCN} was higher for events initiated in the {BL} (67% against 53% in the {FT}). {I}n contrast, higher {CCN} number concentration increases were found when the {NPF} process initially occurred in the {FT}, under less polluted conditions. {T}his work highlights the competition between particle growth and the removal of freshly nucleated particles by coagulation processes. {T}he results support model predictions which suggest that {NPF} is an effective source of {CCN} in some environments, and thus may influence regional climate through cloud-related radiative processes.},
  keywords = {{BOLIVIE} ; {ANDES}},
  booktitle = {},
  journal = {{A}tmospheric {C}hemistry and {P}hysics},
  volume = {17},
  numero = {2},
  pages = {1529--1541},
  ISSN = {1680-7316},
  year = {2017},
  DOI = {10.5194/acp-17-1529-2017},
  URL = {https://www.documentation.ird.fr/hor/fdi:010069317},
}