ESS200A
Prof. Jin-Yi Yu
Thickness of the Atmosphere
qThe thickness of the atmosphere is only about 2% of Earth’s
thickness (Earth’s radius = ~6400km).
qMost of the atmospheric mass is confined in the lowest 100
km
above the sea level.
q Because of the shallowness of
the atmosphere, its motions over large areas
are primarily horizontal.
èTypically, horizontal wind speeds are a thousands time greater than vertical wind speeds.
(But the small vertical displacements of air
have an important impact on the
state of the atmosphere.)
90%
70%
(from Meteorology Today)