Attention Deficit Disorder Prosthetic Memory Program

Fallstreak Hole

ADDPMP558

A fallstreak hole (also known as a cavum, hole punch cloud, punch hole cloud, skypunch, cloud canal or cloud hole) is a large gap, usually circular or elliptical, that can appear in cirrocumulus or altocumulus clouds. Such holes are formed when the water temperature in the clouds is below freezing, but the water, in a supercooled state, has not frozen yet due to the lack of ice nucleation. When ice crystals do form, a domino effect is set off due to the Bergeron process, causing the water droplets around the crystals to evaporate: this leaves a large, often circular, hole in the cloud.

It is thought that the introduction of large numbers of tiny ice crystals into the cloud layer sets off this domino effect of fusion which creates the hole. The ice crystals can be formed by passing aircraft, which often have a large reduction in pressure behind the wing- or propeller-tips. This cools the air very quickly, and can produce a ribbon of ice crystals trailing in the aircraft’s wake. These ice crystals find themselves surrounded by droplets, and grow quickly by the Bergeron process, causing the droplets to evaporate and creating a hole with brush-like streaks of ice crystals below it. An early satellite documentation of elongated fallstreak holes over the Florida Panhandle that likely were induced by passing aircraft appeared in Corfidi and Brandli (1986). Fallstreak holes are more routinely seen by the higher resolution satellites of today. Because of their rarity and unusual appearance, fallstreak holes have been mistaken for or attributed to unidentified flying objects.

Fallstreak Hole - © Attention Deficit Disorder Prosthetic Memory Program
Nasa Aerogel - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP151
Nasa Aerogel
Chicxulub Crater - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP409
Chicxulub Crater
Plan Voisin - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP516
Plan Voisin
Hypersomnia - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP037
Hypersomnia
Ulvetanna - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP101
Ulvetanna
Anechoic Chamber - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP367
Anechoic Chamber
Goûter Refuge - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP228
Goûter Refuge
Colorless Green Ideas Sleep Furiously - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP502
Colorless Green Ideas Sleep Furiously
Grover Krantz - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP341
Grover Krantz
Ijen - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP345
Ijen
Lüscher Color Test - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP545
Lüscher Color Test
Form Follows Function - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP288
Form Follows Function

You are using an outdated browser.
Please upgrade your browser to improve your experience.