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Centre for Atmospheric Science

EMERALD Project - CPI Data - Region 1

CPI data from region 1 clickable lidar plot

Regions 1 and 3 are updraft regions, in supersaturated conditions (wrt ice) of 100-120%RH for region 1 and 100%RH for region 3, with a temperature of about -45 degC. In both these regions a large number of spheroidal and irregular particles were observed, some of which can be seen to be 'budding rosettes', though they do not meet the image analysis software's requirements to be classed as rosettes. A small number of rosettes and columns are also present. It is likely that the small particles are formed by the homogeneous freezing of liquid drops, and these frozen drops then grow by vapour diffusion in the supersaturated conditions to form rosettes.