ABLATION is the calving of glaciers. ABLATION ZONE is when
the glacier’s losses exceed any additional snowfall. Losses occur
through calving or through deflation or melting. Losses cannot
be absorbed in pace (compare accumulation zone).
ADIABATIC is from the Greek meaning “impassable,” and describes
a process in which heat does not enter or leave the system.
In the dictionary, this system is a parcel of air, but does it also
describe bodies in motion. The dictionary speaks of accuracy and
calculations to ascertain its degree. I am not interested in accuracy:
only contact and heat. ADVECTION refers to horizontal motion.
Vertical motion, it states, may be important in certain cases. For example,
in the Hydraulic jump (see bore) that accompanies the *morning glory.
The dictionary does not define AFTERGLOW, which seems like
a missed opportunity. Says only (see alpine glow, see twilight arch)
[Twilight arch is described as a segment of colored light that lies above
the western horizon after the sun has set. (see also purple light).]
AGEOSTROPHIC WIND is an important theoretical wind. We all knew
that of course. AGGREGATION is a term used in *cloud physics,
the definition of which will come later. The definition of AIR
is represented by among other things a chart of atmospheric
abundance. And ALEXANDER’S DARK BAND is another name
for rainbow. When describing ALTITUDE, a negative value
implies that the object is below the horizon. This is also
sometimes known as *elevation. An object sinking below
the horizon invites a kind of melancholy but none so great
as ANTICYLCONIC GLOOM, the saddest entry under A in the
dictionary of weather. Low light, low visibility, dust, and pollutants,
all conspire to dampen an otherwise atmospheric high.