General Geographical Features Test - 1

As part of the Hadley cell, surface air flows toward the equator while the flow aloft is towards the poles. A low-pressure area of calm, light variable winds near the equator is known as the doldrums, near-equatorial trough, intertropical front, or the Intertropical Convergence Zone.

In areas close to the shore, in daytime the land is warmer than the sea. Therefore the air pressure of the land is lower than the sea. As a result, wind usually blows from the sea to the land. Such type of wind is called a "sea breeze".

In an anticyclone, winds move out from a high-pressure area with wind direction clockwise in the northern hemisphere, anti-clockwise in the southern hemisphere. When it displaces the heavier nitrogen and oxygen, it causes an anti-cyclone.

The air around you has weight, and it presses against everything it touches. That pressure is called atmospheric pressure, or air pressure. It is the force exerted on a surface by the air above it as gravity pulls it to Earth.Atmospheric pressure is commonly measured with a barometer.Atmospheric pressure drops as altitude increases.
For example :The atmospheric pressure on Denali, Alaska, is about half that of Honolulu, Hawai'. Honolulu is a city at sea level. Denali, also known as Mount McKinley, is the highest peak in North America.

According to NASA, the gases in Earth's atmosphere include:
Nitrogen — 78 percent.
Oxygen — 21 percent.
Argon — 0.93 percent.
Carbon dioxide — 0.04 percent.

Cyclone is a large scale air mass that rotates around a strong center of low atmospheric pressure. Cyclones are characterized by inward spiraling winds that rotate about a zone of low pressure.

A blizzard is a severe snowstorm characterized by strong sustained winds of at least 56 km/h (35 mph) and lasting for a prolonged period of time—typically three hours or more. A ground blizzard is a weather condition where snow is not falling but loose snow on the ground is lifted and blown by strong winds.

The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet radiation. It contains high concentration of ozone (O3) in relation to other parts of the atmosphere, although still small in relation to other gases in the stratosphere.

The atmosphere can be divided into layers based on its temperature:
The troposphere is the lowest layer of Earth's atmosphere, and is also where nearly all weather conditions take place. It contains approximately 75% of the atmosphere's mass and 99% of the total mass of water vapor and aerosols.
The tropopause is the boundary in the Earth's atmosphere between the troposphere and the stratosphere.
The stratosphere is the second major atmospheric layer above the troposphere and tropopause extending in altitude from about 8 to 30 miles high. No weather occurs in the stratosphere.
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 above the Earth.

A barometer is a scientific instrument used in meteorology to measure atmospheric pressure. A simple barometer consists of a long glass tube (closed at one end, open at the other) filled with mercury and turned upside down into a container of mercury.