The envelope of air that surrounds the Earth where all weather events happen is called (1) ___________. It is
divided into five layers based on the (2) ____________________ and (3) ____________________.
The (4) ____________________ is the layer closest to Earth’s surface. The temperature just above the ground
is hotter than the temperature high above. Weather occurs in the troposphere because this layer has most of the water
vapor.
The (5) ____________________ is the layer of air that extends to about 50 km from the Earth’s surface. Many
jet planes fly in the stratosphere because it is very stable. It is in the stratosphere that we find the ozone layer.
The layer between 50 km and 80 km above the Earth’s surface is called the (6) ____________________. Air in
this layer is very thin and cold. Meteors or rock fragments burn up in here.
The (7) ____________________ is between 80 km and 110 km above the Earth. Space shuttles fly in this area,
and it is also where the auroras are found. Auroras are caused when the solar wind strikes gases in the atmosphere
above the Poles.
The upper limit of our atmosphere is the (8) ____________________. This layer of the atmosphere merges into
space. Satellites are stationed in this area, 500 km to 1000 km from Earth.
The Earth’s atmosphere is compared to a greenhouse. The process by which the Earth’s atmosphere warms up
is called (9) ____________________ and the trace gases are referred to as (10) ______________.