ESS220
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)