Weather Projects for Young Scientists: Experiments and Science Fair Ideas
book further designing and doing your own experi ments for fun or as school projects Look for the Science Fair Spin label for ideas to get you started Key terms are in bold upon their first appearance and are defined in the glossary at the end of the book Lastly make sure to check out the weather Web sites on page
The Air Around Us he earth is surrounded by a blanket of air called the atmosphere Earth's air is mostly nitrogen and oxygen gas with small amounts of water vapor carbon dioxide and a few other trace gases See the pie chart at right The earth's gravitational pull anchors the atmosphere to the planet Gravity keeps air from drifting off into outer space What s in Air nitrogen 76 4 Oxygen 20 6 water vapor 2 carbon dioxide argon and other gases less than
This photo taken by the space shuttle shows Earth's lower atmospheric layers lit by the setting sun The bottom layer is the troposphere and the top brighter layer is the stratos phere Layers of Air Scientists divide the atmosphere into four main lay ers See diagram on page 3 The layer closest to the ground is the troposphere It goes from the surface to about 7 miles 11 km up It has the most air and moisture of all the layers It's where most weather happens In this layer temperature decreases with height so higher altitudes are colder The stratos phere is from about 7 to 30 miles 11 to 48 km above the ground There is little mixing between the stratosphere and the troposphere so hardly any water vapor and dust make it into the stratosphere At the top of the stratosphere and into the mesos phere is the ozone layer the band of O3 Or
that blocks much of the sun's dangerous ultraviolet UV radiation from reaching the earth's surface Ozone blocks UV radiation by absorbing it While doing so it also heats up the stratosphere which is actually warmer at its top than at its bottom The mesosphere is from 30 to 50 miles 48 to 80 km above the earth The temperatures in this layer again begin to decrease with height reaching as low as 90°F 68°C No commercial aircraft fly this high only research weather balloons The thermosphere is the layer from 50 to 180 miles 80 to 290 km up or more After it is interplanetary space or the exos phere It gets super hot in the thermosphere up to more than 3 000°F 1 650°C The lower part of the thermosphere is also called the ionosphere and con tains electrically charged particles or ions Radio waves are reflected back to the earth by this layer It s also where high energy atomic particles from the sun collide with gases and produce beautiful streaks of colored light called auroras or the northern
