Premium
The impact of freezing of sulfate aerosols on the formation of polar startospheric clouds
Author(s) -
Larsen Niels
Publication year - 1994
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/93gl03545
Subject(s) - aerosol , nucleation , ice nucleus , sulfate , polar , stratosphere , sulfuric acid , atmospheric sciences , cloud condensation nuclei , particle (ecology) , nitric acid , population , mineralogy , environmental science , chemistry , meteorology , geology , inorganic chemistry , physics , oceanography , demography , organic chemistry , astronomy , sociology
In simulation models, used to describe the formation of Polar Stratospheric Clouds (PSC), it is usually assumed that the background population of sulfate aerosols acts as nucleation centers for the PSCs. At normal stratospheric temperatures the aerosols are in the liquid phase, not suitable for PSC nucleation, but still it has been assumed that the particles will freeze above the nitric acid trihydrate (NAT) condensation temperature. Homogeneous freezing of aerosol particles into sulfuric acid tetrahydrate and ice has been incorporated in a detailed microphysical PSC‐model to investigate the impact of freezing among the sulfate aerosols on the PSC size distributions. It is demonstrated here that freezing of the largest particles might explain the observed high HNO 3 /NAT saturation ratios and denitrification by particle sedimentation in the Arctic stratosphere. Comparisons have also been made to the PSC formation under Antarctic temperature conditions.