Lenticular and wave clouds
(Whiteman ppt)
a, b, & g:
Brooks Martner photos
Whiteman (2000) |
11 |
Leewave clouds, wakes (Whitemanit ppt)t
http://wwwhttp:// ..wrhrh..noaanoaa..gov/spokane/pixgov/spokane/pix__month/wavesonth/ aves..hh
tmtm |
MODISIS satellites t llite |
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Wave clouds over Cascades and Rocky Mtns of MT and Alberta |
Smithith et al. (1997) |
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et al. (1997) |
12 Wave clouds induced by South Sandwich Islands on 27 January 2004, MODIS satellite
Wakes турбулентный след
(Whiteman ppt)
Orgill (1981) |
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Wake (Whiteman ppt)
From Erick Brenstrum |
14 |
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(Whiteman ppt)
Kelvin-Helmholz instability
©Rickick Dunnunn 19951995 www..RJDphotoJ photo..comcom
15
©Amyy FlygareFlygare
(Whiteman ppt)
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Matterhorn banner cloud (Whiteman ppt)
Whiteman (2000)
17
Blocked flow New Zealand
(Whiteman ppt)
Whiteman photo |
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Notion on cloud cells
Observation (including satellite ones) show that clouds often exist in form of mesoscale objects that are called cloud cells. These cells have a form of not fully regular systems – hexagons. The cells are not the only systems; there are also bands and banks of clouds.
Benar (1900) and Rayleigh (1916) were the first to discover this kind of cloud
field structure. According to Rayleigh’s investigations, |
regime of motion |
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causing waves and cloud formation depends on non-dimensional number |
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h4 |
Depth of convective layer |
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Ra |
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Temperature conductivity |
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T K |
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Molecular viscosity |
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z |
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Open cell |
Ra Racr |
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Wavelike motion of the cell |
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type; unstable waves |
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0 |
Ra Racr |
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Any type of motion; waves |
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(if any) are stable |
Closed cell |
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z |
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Over cold surface |
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Over warm surface |
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