and air movement is primarily horizontal. There is little manifestation of weather-type processes. The stratosphere and the atmospheric layers above it make up the upper atmosphere
the troposphere being the lower atmosphere. Above the stratopause
temperature decreases with altitude to â90°C (â130°F) at 85 km (52.7 mi)
the coldest location in the atmosphere. This region
the mesosphere
is characterized by rapid vertical mixing. The atmosphere 11