the edge of space

An introduction to our active ionosphere

begin

Layers of the Atmosphere• Troposphere 0 – 18 km weather• Stratosphere 5 – 50 km ozone layer• Mesosphere 50 – 90 km shooting stars• Ionosphere 90 – 600 km space shuttle, aurora

(aka thermosphere) • Magnetosphere 60,000 km edge of space

Temperature change

The density of the atmosphere decreases with increasing altitude

Temperature varies greatly throughout the atmosphere – defining its layers.

Chemicals in the Atmosphere

Nitrogen (N2) 78%

Oxygen (O2) 21%

Argon (Ar) 1%

Water Vapor (H2O) 0-7%

Ozone (O3) 0-0.01%

Carbon Dioxide (CO2) 0.01-0.1%

What is the Ionosphere?• It is a conducting layer in the atmosphere that can reflect

radio signals (learn more).• It protects us from dangerous radiation.• It is the closest natural plasma (0.1% ionized plasma from

70 – 1500 km)

Why study the ionosphere?

• To increase the accuracy of the Global Positioning System (GPS) learn more

• To increase the reliability of worldwide radio communication with High Frequency radio waves. This was studied extensively during World War II

• To increase the effectiveness of satellite communications

• To determine the connection, if any, between the ionosphere and our weather.

• To understand better the interaction between the sun and the Earth.

Solar Storms

From time to time, the sun emits huge amounts of plasma into the solar system. Although the magnetosphere shields the Earth from most of the radiation, some penetrates through to the ionosphere. Once there, it can cause all sorts of trouble. Scientists need good space weather forecasts to prepare for these disturbances. (learn more)

Anatomy of the ionosphere• D layer (50 – 95 km)

absorbs some radio waves

• E layer (90 – 140 km) first part discovered

• F layer (160 – 400 km) absorbs most of the harmful UV radiation from the sun. The ozone layer absorbs the rest of it.

• Radio waves reflect off both the E & F layers

Day & Night

The ionosphere changes dramatically every night. Without the influx of solar power, the matter loses some of its energy. This decreases the plasma density, especially at lower altitudes. AM radio waves take advantage of this “higher” ionosphere and reflect to farther distances. (learn more)

The Magnetosphere

protects the ionosphere from the solar wind (the charged particles emitted by the sun). The sun sometimes emits very large amounts of matter all at once in a coronal mass ejection (CME). This can lead to solar storms which knock out communications worldwide. (learn more)

Really cool movies!!!• Our active sun • CME• Magnetosphere animation• magnetosphere data