Hole-punch clouds over eastern China

Holepunch clouds over eastern China

28 December 2016 01:00–06:00 UTC

Hole-punch clouds over eastern China
Hole-punch clouds over eastern China

On 28 December 2016 holepunch clouds or fallstreak holes developed over eastern China.

Last Updated

22 October 2020

Published on

28 December 2016

By HansPeter Roesli (Switzerland) and Jochen Kerkmann (EUMETSAT) and Djordje Gencic (RHMSS ).

A holepunch cloud is a large gap, usually circular or elliptical, that can appear in cirrocumulus or altocumulus clouds. They form when part of the cloud layer forms ice crystals which are large enough to fall as a 'fallstreak'.

 Himawari-8 Cloud Phase RGB, 28 Dec 02:20 UTC. Black arrow indicate the holes.
Figure 1: Himawari-8 Cloud Phase RGB, 28 Dec 02:20 UTC. Black arrow indicate the holes.

They result from a combination of cold temperatures, air traffic, and atmospheric instability. The holes form in clouds of supercooled water droplets, water below 0 °C but not yet frozen. These water droplets need a tiny particle, a nucleus, to freeze or to be cooled below -40 °C.

 
 Himawari-8 VIS0.64, 0.5 km at SSP, 28 December 01:00–06:00 UTC
Figure 2: Himawari-8 VIS0.64, 0.5 km at SSP, 28 December 01:00–06:00 UTC

Using Himawari-8 imagery it was possible to clearly see these holes that developed over China, see the Himawari-8 Cloud Phase RGB, (NIR1.6-NIR2.3-VIS0.5), 28 Dec 02:20 UTC (Figure 1).

The animated gif of Himawari-8 visible imagery, 28 December 01:00–06:00 UTC (Figure 2), shows the very fast evolution of these features over couple of hours.

The radiosounding of Nanjing (from University of Wyoming) indicated the probable height of these clouds, namely 350 hPa (about 8400 m).

On the AHI Convection RGB, 28 December 14:00 UTC (Figure 3) the distrails are seen very clearly, with good contrast.

 Himawari-8 Convection RGB, 28 December 02:30 UTC
Figure 3: Himawari-8 Convection RGB, 28 December 02:30 UTC

Related Content

Punching Through (NASA Earth Observatory)

Previous case study

Distrails over Central Europe (6 November 2013)