Observations of a glaciating hole-punch cloud

TL;DR

This study presents remote-sensing observations of a hole-punch cloud, revealing the cloud's composition, structure, and potential formation mechanisms through multiple instruments.

Contribution

It provides detailed multi-instrument observations of a hole-punch cloud, highlighting the role of ice crystals and vertical mixing in its formation.

Findings

The fall streak was mainly composed of oriented thick plate ice crystals.

Vertical Doppler velocities indicate vertical mixing triggered by ice flux.

Multiple remote sensing instruments effectively characterized the cloud.

Abstract

Remote-sensing measurements of a hole-punch cloud or fall-streak hole are presented. The cloud was observed with a vertically pointing infrared ceilometer, Doppler lidar, sky camera and a polarimetric radar inclined at 45 degrees. The Doppler lidar and polarimetric radar observations show that the aircraft-induced fall streak was composed primarily of oriented thick plate crystals, and the vertical Doppler velocities suggest that vertical mixing may have been triggered by the large flux of ice into the dry air at the base of the virga.