[FRIAM] Manifold Clarification

[thompnickson2 at gmail.com]

Steve, 

Before you came on FRIAM, during the slandering phase of my presentation, I argued that a cloud consisted of a complex surface each point on which met the following condition: the dewpoint temperature of the air of the air is equal to the ambient temperature of the air.   Furthermore, "inside" this boundary, the dewpoint temp is above the ambient temperature, and outside it is below.  Both dewpoint temperature This explains why cumulus clouds have flat bottoms: cumulus clouds are visualization of rising columns of air. As the air rises, its pressure and temperature fall, and when they fall below the dewpoint, we see the cloud.. Now this, like any description, is a model, and leaves out a lot of complexity.  One of the complexities omitted is the fuzziness of the boundary, particularly at the top of the cloud.  Another complexity left out by the model is supper cooled water vapor, which I gather occurs because water, to condense, has to find some particle to condense on.  So there are parts of the cloud that are saturated but no condensation has occurred.  In a fire cloud, I gather, not only does the fire add water vapor, it adds soot, so, I am guessing, condensation occurs more rapidly and also, guess heaped upon a guess, the release of the latent heat in the water vapor also occurs more vigorously than in  a column of non fire related cumulus.  A third complexity arises from the heat realized by the freezing of the condensed water.  This two, requires nuclei, and so is delayed way above the freezing level of the atmosphere.  When the rising column hits the stratosphere, there is a temperature inversion and further lifting ceases and the cloud, now ice crystals, spreads out laterally in the characteristic anvil.  

This all I believe because it was shown unto me by God.  If God was wrong about any of this, I do hope all you former pilots will correct me. 

Some day I am going to take a meteorology course.  Perhaps I will enroll in a meteorology program when I am 85.  

Nick  

Nicholas Thompson
Emeritus Professor of Ethology and Psychology
Clark University
ThompNickSon2 at gmail.com
https://wordpress.clarku.edu/nthompson/
 


-----Original Message-----
From: Friam <friam-bounces at redfish.com> On Behalf Of Steve Smith
Sent: Friday, June 5, 2020 8:30 PM
To: The Friday Morning Applied Complexity Coffee Group <friam at redfish.com>
Subject: Re: [FRIAM] Manifold Clarification


> I said that no physical object is a manifold.  This may be a better 
> answer to Nick's question.  The envelope of a cloud, if it could be 
> defined, might be a manifold depending on cusps etc.  Those might be 
> handled by combining manifolds of different dimensions.  This would 
> not be a realizable project in my opinion.
>
> Frank

More likely darn near a fractal surface... down to the size of a condensed droplet of water?  Ken Perlin's cloud-modeling comes to mind (multi-scale if not literally fractal).

But model(ed/able) as an idealized manifold based on the triple-point of water (or is that only clouds forming hail or sleet?) 

Nick? mentioned "shroud" which I don't think has a mathematical definition but i took it to mean something like a convex-hull (shrink-wrapped surface).  From work with Stephen on using imagery of clouds (or plumes) to calibrate cameras and to estimate their shape as a function of time, we have looked at things like silhouette analysis.  

Clouds and plumes are not entirely opaque and I believe that is because they are "porous'...   I'm not sure if there are examples in nature of fully saturated water vapor...  maybe only in a vacuum?   Clouds are (I'm pretty sure) condensed droplets of water vapor dispersed among air molecules (I suppose I could read up  more on cloud science).  Plumes (smoke from a wildfire) are a little more complex but have a significant component of water vapor/droplets as well as hydrocarbon particulates? Guerin is surely much more up on this.   During the 2011 Cerro Grande Fire, we had *baked* pine needles settling around our property... they were not burned, but may have been fully charred (all volatiles pyrolized), probably in such an oxygen poor environment that they couldn't burn.   This was probably a "sorting" process... smaller bits may have traveled further while larger ones (twigs and branches) fell short(er)...  

- Steve



- .... . -..-. . ...- --- .-.. ..- - .. --- -. -..-. .-- .. .-.. .-.. -..-. -... . -..-. .-.. .. ...- . -..-. ... - .-. . .- -- . -..
FRIAM Applied Complexity Group listserv
Zoom Fridays 9:30a-12p Mtn GMT-6  bit.ly/virtualfriam un/subscribe http://redfish.com/mailman/listinfo/friam_redfish.com
archives: http://friam.471366.n2.nabble.com/
FRIAM-COMIC http://friam-comic.blogspot.com/