Unusual Weather: Lecture 10&11
pressure gradient force
causes air to move from a higher pressure toward lower pressure
horizontal pressure differences
caused by temperature differences
the gas law formula
pressure=temp x density x constant
the gas law
temp increases, density decreases if pressure is constant.
constantly pulling the wind to its right in NH and left in SH
horizontal pressure changes
much less than vertical. wind blows from high pressure
sea pressure correction
10 mb for 100 m above sea levels. always add on pressure if going down to sea level.
large scale (synoptic) weather systems
winds blow counterclockwise around the low pressure system in norther hemisphere.
pressure gradient force winds
high to low pressure
coriolis force winds
directed to the right
air from equator creates an area of high pressure
air moves toward the poles and deflects toward the east, resulting in westerly flow
polar air deflected by the coriolis force resulting in a NE flow
high pressure areas
near lat. 30 latitudes and near the poles
low pressure areas
near the equator and at 60 latitudes
air currents thousands of miles long, hundreds of miles wide. wind speed can exceed 100 mph. found near the tropopause.
constant pressure surface
southern hemisphere, counterclockwise
clockwise, northern hemisphere