Re: [Phys-l] atmosphere : large-scale patterns

[Bernard Cleyet <bernardcleyet@redshift.com>]

      Continental / Oceanic Patterns

Now let us add a couple more facts:

  1. The sun is not very effective at heating the air, especially dry
     air. Normally, the sun heats the surface of the planet, then the
     air gains heat from the surface --- partly by simple contact, and
     partly by absorbing energy-rich water vapor that evaporates from
     the surface.
  2. When we change from winter to summer, solar heating warms the dry
     land much more quickly than the ocean.8
     <http://av8n.com/how/htm/atmo.html#note264> This is because the
     ocean is constantly being stirred. To heat up the land, you need
     only heat up the top few inches of soil. To heat up the ocean, you
     need to heat up several feet of water.

As a consequence, in temperate latitudes, we find that in summer, the 
land is hotter than the ocean (other things, such as latitude, being 
constant), whereas in winter the land is colder than the ocean.

This dissimilar heating of land and water creates huge areas of low 
pressure, rising air, and cyclonic flow over the oceans in winter, along 
with a huge area of high pressure and descending air over Siberia. 
Conversely there are huge areas of high pressure, descending air, and 
anticyclonic flow over the oceans in summer.

These continental / oceanic patterns are superimposed on the primary 
circulation patterns. In some parts of the world, one or the other is 
dominant. In other parts of the world, there is a day-by-day struggle 
between them.

----------------

Diurnally instead of seasonally this occurs very often in the Salinas 
Valley.  That's the main reason I enjoy living here.  Salinas is in the 
ideal location; not on the coast (Monterey) where it's too cold and 
humid, and not further south  where it's desert (King City) and waaay 
too hot.  In the day time the valley heats up a lá JD the air rises and 
vacuums in the cold humid air from the Monterey bay.  In the evening the 
reverse occurs, tho to a lesser extent. 

bc, who in Elem. boating and Sailing class (UCSB) noted similarly in 
Santa Barbara.

p.s. The Salinas Valley is like a funnel; at the south end it narrows to 
a coupala hundred feet and rises to 1500.  At the N. (ocean) end it's 15 
miles wide.  The surrounding Santa Lucia and Gabilan mountains are 
typically one to two thousand high w/ one ridge over 5k feet

John Denker wrote:

> The dominant large-scale features of the atmosphere are summarized
> by the /tricellular model/ i.e. the Hadley cell, the Ferrel, cell,
> and the polar cell.
>
> The picture is worth 1000 words:
>  http://av8n.com/how/htm/atmo.html#fig-cells
>
> Roughly speaking, this explains why (generally speaking) you are not
> surprised to see
> -- lots of rainfall near 0 degrees and 55 degrees latitude, and
> -- very dry conditions near 25 degrees and 90 degrees latitude.
>
>  http://av8n.com/how/htm/atmo.html#sec-prevailing-winds
>  http://en.wikipedia.org/wiki/Atmospheric_circulation
>
>  Also the Britannica has a nice article on atmosphere, weather and
>  climate: readable and informative.
>
> I find this a fascinating subject.  It can be presented at a qualitative
> level.  The tricellular model allows a unified view of many phenomena,
> including horse latitudes, doldrums, trade winds, prevailing westerlies,
>
>  
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