[轉錄]Re: Waves of Fog

※ 本文轉錄自 [Meto_e] 看板

發信人: isohume <[e-mail]>, 看板: Meto_e
標  題: Re: Waves of Fog
發信站: Posted via Supernews, http://www.supernews. (Mon Nov  8 07:47:46 2004)
轉信站: itcz!news2.wam.umd.edu!bloom-beacon.mit.edu!newsfeed.stanford.edu!sn-xi

Great pics!

These fog plumes form over the the Great Lakes too. As the advection fog
    moves northward along the coast, they eventually interact with the
coastline, which produces shockwaves (gravity waves). These internal
upward and downward waves remain trapped in the strong low level
temperature inversion.

http://webpages.charter.net/isohume/modis.jpg

Garry W wrote:
> Falk Tannh瓣user <[e-mail]> wrote:
>
>>Garry W wrote:
>>
>>>www.extremelyserious.org/photos/WavesOfFog.
>>>I'm wondering... how does it do that?
>>
>>I imagine there was wind shear between the lowest air
>>layer (containing wet cool air) and higher layer (with
>>warmer, drier air). Similar waves with characteristically
>>shaped clouds (can be stratocumulus, altocumulus, cirrus...)
>>sometimes appear at temperature inversions in higher
>>altitudes - you may want to google for "Kelvin-Helmholtz
>>effect / instability / clouds".
>
>
> Okay, I see all the pages, and they make sense. But if it was K-H, the fog in
> my pictures must have been right on the beginning of K-H instability -- there
> was no room right there on the sea surface for the big vertical K-H
> instabilities, like I see depicted on the web pages, to have formed. But if
> it was just on the beginning of K-H, it's remarkable that I could have had
> such a well-formed train of waves...
>
> I searched further, and found something related, called "Horizontal
> Convective Rolls", also known as "cloud streets". They =are= known to occur
> at the sea surface, and might be a closer match to what I was seeing. I can
> find no optical images of the effect at sea-surface, though (just radar), so
> I'm not sure if that's what I had either!
>
> Anyhow. I liked my pictures.
>
> thanks,
> Garry