© Michael Bruhn

Aspendale Gardens VIC 3195, Australia

Latitude: 38° 1' 30'' S

Longitude: 145° 6' 57'' E

28 December 2016 2047 (Local Time)
Camera direction: towards E

Image P/S code: P.4.10

Image I.D.: 5738

C_L = 0, C_M = 8, C_H = 0

• Images & related info Other Images Images of 1987 edition
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  Altocumulus castellanus duplicatus

  The setting Sun highlights three layers of Altocumulus in this image. The lowest layer, coloured pink, has small turrets rising from elements with a common base (species castellanus). Tufts of Altocumulus floccus are also present at the same base; these tufts have evolved from castellanus where the base has dissipated.

  The next highest layer is directly above the lowest layer and extends further westward. Its western edge is just starting to redden; the Sun is not quite low enough to colour its under surface. 

  The highest layer is thin and more extensive than the lower layers. It is classified as Altocumulus stratiformis translucidus. 

  Links in the image description will highlight features on the image. Mouse over the features for more detail.

  © Michael Bruhn
  Aspendale Gardens VIC 3195, Australia
  Latitude: 38° 1' 30'' S
  Longitude: 145° 6' 57'' E
  28 December 2016 2047 (Local Time)
  
  
  Camera direction: towards E
  C_L = 0, C_M = 8, C_H = 0
  Image P/S code: P.4.10
  Image I.D.: 5738
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  A low pressure system and associated trough were moving in from the west. 

  © Commonwealth of Australia 2016, Bureau of Meteorology
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  The sounding shows a dry adiabatic lapse rate from near the surface to 680 hPa. The two lower cloud layers ranged from 730 to 700 hPa, with the highest layer at 644 hPa. 

  © University of Wyoming
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  Altocumulus stratifromis translucidus perlucidus duplicatus

  The genus of both of these cloud sheets is Altocumulus. The regularly arranged elements are as wide as 1 to 3 fingers held at arm's length. This is too small for Stratocumulus and too large for Cirrocumulus. Slight shading in the higher sheet and significant shading in the lower sheet also indicate that it is not Cirrocumulus, which must be devoid of any shading.

  The sheets are thin enough throughout to reveal the position of the Sun (variety translucidus) and both sheets have distinct small spaces between the elements (variety perlucidus). In the higher sheet, the blue of the sky can be seen through these gaps, while in the lower sheet, the light grey of the higher sheet can be discerned.

  Overlapping of the two sheets can be seen in the middle on the horizon.

  The coding is C_M=7 as both sheets were receding; the clearing edge is visible on the lower left.

  Links in the image description will highlight features on the image. Mouse over the features for more detail.

  © Kam Hoo Man
  Yuen Long, Hong Kong, China
  Latitude: 22° 26' 40'' N
  Longitude: 114° 1' 20'' E
  23 November 2013 1021 (Local Time)
  
  
  Camera direction: towards ESE
  C_L = 0, C_M = 7, C_H = 0
  Image P/S code: S.4.10 1
  Image I.D.: 5834
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  Altocumulus lenticularis and rotor clouds

  This picture shows orographic clouds in the lee of the Andes mountains during a foehn wind event. Prominent in the centre and on the right are Altocumulus lenticularis wave clouds. More than one wave layer is visible, indicating the variety duplicatus. Orographic Cirrus has formed above. The line of Cumulus has likely formed on a rotor, which is an eddy of air rotating along a horizontal axis. On the left of the image is a bank of Stratocumulus.

  Links in the image description will highlight features on the image. Mouse over the features for more detail.

  © Maximiliano Viale
  El Cholar, Neuquén, Argentina
  Latitude: 37° 26' 35'' S
  Longitude: 70° 38' 31'' W
  31 October 2016 0514 (Local Time)
  
  
  Camera direction: towards NW
  C_L = 8, C_M = 4, C_H = 1
  Image P/S code: S.4.3
  Image I.D.: 6083