Antarctica has a climate with average temperatures
well below zero degrees Fahrenheit. The annual average high temperature in
Antarctica is -49 degrees Fahrenheit. Although Antarctica's atmosphere is
normally below freezing, there can still be water droplets, along with ice
crystals, found in the clouds. In the interior of Antarctica the temperature is
much colder, causing the clouds to be made up of solely ice crystal particles.
The consistency of the clouds made solely of ice crystals, are mostly thinner and
fine in form. Due to the climate of Antarctica, deep convective clouds, like
those found in thunderstorms, cannot be found in Antarctica’s atmosphere. Deep
convective clouds are classified as cumulonimbus clouds that can be many
kilometers thick, with its base near the Earth’s surface. For these
cumulonimbus clouds to form there must be a warm surface to start the
convection of the cloud, a characteristic not found in Antarctica.
Standing Lenticular clouds over the Transarctic Mountains, common among mountain ranges.
Image courtesy of http://icestories.exploratorium.edu/dispatches/altocumulus-standing-lenticular-clouds
Lenticular clouds are often formed when
mountains create an obstruction for the wind flow, creating turbulence and
uplift. Lenticular clouds are often lens shape stationary clouds formed in high
altitude, perpendicular in alignment to the wind direction. How can clouds be
created due to the obstruction of wind flow? An offer to this explanation is
when moist air flows over a mountain range, standing waves of air can form on
the down side of the mountain. Then the temperature in the standing air wave
must reach the dew point in order for moisture in the air to condense and form
lenticular clouds. Dew point is the temperature air must be cooled, at constant
air pressure, in order for saturation to occur in respect to a plane surface of
water. In order to create saturation the rate of evaporation and condensation
must be equal. However, just because the air temperature has reached the dew
point temperature does not mean there is going to be precipitation. The process
for rain or snow is more complicated than the dew point, taking into consideration
the type and size of cloud condensed nuclei that water vapor can condense upon
is another process.
References:
·
http://traveltips.usatoday.com/average-temperature-antarctica-13726.html
Image courtesy of http://icestories.exploratorium.edu/dispatches/altocumulus-standing-lenticular-clouds
