TY - JOUR
T1 - Calculation of supersaturation maximum and droplet concentration at cloud boundaries
AU - Pinsky, Mark
AU - Khain, Alexander
N1 - Publisher Copyright:
© 2019
PY - 2020/4
Y1 - 2020/4
N2 - Most parameterizations of droplet concentration at cloud base in cloud models are derived under the assumption that all droplets at the cloud base form by nucleation of dry CCN crossing the lifting condensation level in updraft. In this study, a novel method of calculation of the supersaturation maximum and droplet concentration at cloud base is described that takes into account the existence of liquid at the level of droplet nucleation. Liquid exists in haze particles, as well as in the form of cloud droplets and raindrops. It is shown that the presence of liquid water inside non-activated CCN, as well as of cloud droplets and raindrops substantially decreases supersaturation maximum in case of high aerosol concentration. The possible effect of the supersaturation maximum decrease on formation of DSD in clouds is discussed. The method can be also applied to calculation of supersaturation and droplet nucleation at cloud edges.
AB - Most parameterizations of droplet concentration at cloud base in cloud models are derived under the assumption that all droplets at the cloud base form by nucleation of dry CCN crossing the lifting condensation level in updraft. In this study, a novel method of calculation of the supersaturation maximum and droplet concentration at cloud base is described that takes into account the existence of liquid at the level of droplet nucleation. Liquid exists in haze particles, as well as in the form of cloud droplets and raindrops. It is shown that the presence of liquid water inside non-activated CCN, as well as of cloud droplets and raindrops substantially decreases supersaturation maximum in case of high aerosol concentration. The possible effect of the supersaturation maximum decrease on formation of DSD in clouds is discussed. The method can be also applied to calculation of supersaturation and droplet nucleation at cloud edges.
KW - Cloud base supersaturation maximum
KW - Droplet concentration
KW - Nucleation
UR - http://www.scopus.com/inward/record.url?scp=85074726976&partnerID=8YFLogxK
U2 - 10.1016/j.atmosres.2019.104694
DO - 10.1016/j.atmosres.2019.104694
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AN - SCOPUS:85074726976
SN - 0169-8095
VL - 234
JO - Atmospheric Research
JF - Atmospheric Research
M1 - 104694
ER -