|
|
What happens inside a cloud?
Large-scale Processes
Take a look at the illustration below. Large-scale organization of low clouds
occurs over the tropical and
subtropical oceans such as
the Pacific Ocean
between southern California and Hawaii. Decks of
stratus clouds on the
eastern side of the ocean basin transition to
cumulus clouds farther west. These
systems of clouds form under
subtropical high pressure
systems which are
characterized by sinking air. The direction of the surface winds causes
upwelling
along the coast. As a result, the air in the lower atmosphere, called
the boundary layer is cool and moist. The
relative humidity of the
surface air is usually in excess of 75%. Also, the ocean water gets warmer to
the west, resulting in
convection in the
boundary layer. Clouds form where the
air is rising, and the sky is clear where air is sinking. This is why the deck
of stratus clouds transitions to individual cumulus clouds.
Next page
->
Making Rain
Links and resources
Large-scale Processes
Take a look at the illustration below. Large-scale organization of low clouds
occurs over the tropical and
subtropical oceans such as
the Pacific Ocean
between southern California and Hawaii. Decks of
stratus clouds on the
eastern side of the ocean basin transition to
cumulus clouds farther west. These
systems of clouds form under
subtropical high pressure
systems which are
characterized by sinking air. The direction of the surface winds causes
upwelling
along the coast. As a result, the air in the lower atmosphere, called
the boundary layer is cool and moist. The
relative humidity of the
surface air is usually in excess of 75%. Also, the ocean water gets warmer to
the west, resulting in
convection in the
boundary layer. Clouds form where the
air is rising, and the sky is clear where air is sinking. This is why the deck
of stratus clouds transitions to individual cumulus clouds.
