According to the prevailing view in the Global Electric Circuit community, the Earth’s surface is negative relative to the lower edge of the ionosphere, which is believed to be positive. The positive hole charge carriers dominate the electrical conductivity throughout the upper to middle crust.

the ionosphere is important because it reflects and modifies radio waves used for communication and navigation. Other solar phenomena, such as flares, and changes in the solar wind and geomagnetic storms also effect the charging of the ionosphere.

about 48 kilometers

1 Answer

• Correct option: (4) F2 layer.
• Explanation:
• The approximate height of the four layers is as follows.
• D layer – 65–75 km.
• E layer – 100 km.
• F1 layer – 170–190 km.
• F2 layer – 300 km (at night) and 250–400 km (during day)

The ionosphere is defined as the layer of the Earth’s atmosphere that is ionized by solar and cosmic radiation. It lies 75-1000 km (46-621 miles) above the Earth. (The Earth’s radius is 6370 km, so the thickness of the ionosphere is quite tiny compared with the size of Earth.)

In the troposphere, the temperature generally decreases with altitude. The reason is that the troposphere’s gases absorb very little of the incoming solar radiation. Instead, the ground absorbs this radiation and then heats the tropospheric air by conduction and convection.

As you increase in elevation, there is less air above you thus the pressure decreases. As the pressure decreases, air molecules spread out further (i.e. air expands) and the temperature decreases. If the humidity is at 100 percent (because it’s snowing), the temperature decreases more slowly with height.

The temperature ranges from negative 5 degrees Fahrenheit (negative 15 degrees Celsius) at the stratosphere boundary to negative 184 degrees Fahrenheit (negative 120 degrees Celsius) at the upper boundary.