© Akihito Umehara
Aomori airport, Japan
Latitude: 40° 44' 17'' N
Longitude: 140° 41' 19'' E
28 September 2012 0604 (Local Time)
Camera direction: towards WNW
Image P/S code: P.1.12
Image I.D.: 5037
CL = 0, CM = 3, CH = 2
This is an outstanding example of a very thick, dense and large patch of Cirrus spissatus with mamma. The observation of Cirrus is confirmed by the cirriform top, ice crystal striations, shading (which is a common feature of thick spissatus) and a nearby upper-air sounding indicating cloud at 7 000 m.
Trails of ice crystals can be seen on the back edge. The Cirrus appears to be the remains of the upper part of a Cumulonimbus; however, there was no Cumulonimbus activity in the area. Numerous small patches of thin Altocumulus are also present.Links in the image description will highlight features on the image. Mouse over the features for more detail.
The sounding is from less than 2 hours after the photo was taken. There is a conclusive moisture signature at 424 hPa with a dew point depression of 2.1 °C.
An example of Cirrus spissatus – the hanging protuberances below the cloud are the infrequently seen supplementary feature mamma.
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Cirrus are detached clouds in the form of white, delicate filaments or white or mostly white patches or narrow bands. They have a fibrous (hair-like) appearance or a silky sheen, or both. In this striking image, the Cirrus is in thick patches with a smooth surface and is sufficiently dense to appear greyish when viewed towards the Sun, which identifies the species as spissatus; patches may also veil the Sun, obscure its outline or even hide it. Of significance are two small but distinct areas with hanging protuberances like udders on the under surface of the cloud, seen at 2 and 3. These are the supplementary feature mamma.
Links in the image description will highlight features on the image. Mouse over the features for more detail.