Pressure differences between different regions of the atmosphere are the primary force that drives atmospheric circulation. Air moves from areas of high pressure to areas of low pressure, creating winds and weather patterns.

Convection is the transfer of heat through the movement of fluids. In the atmosphere, convection occurs when warm air rises and cool air sinks, creating currents that transport heat and moisture.

Condensation is the process by which water vapor in the air condenses into liquid water. This occurs when the air temperature drops below the dew point, causing the water vapor to condense into tiny water droplets.

Evaporation is the process by which water moves from the Earth's surface to the atmosphere. This occurs when water molecules absorb energy from the sun and break free from the liquid water, turning into water vapor.

Precipitation is the process by which water falls from the sky to the Earth's surface. This occurs when water droplets in the atmosphere become too heavy to stay suspended and fall to the ground.

Transpiration is the process by which plants release water vapor into the atmosphere. This occurs when water molecules move from the roots of the plant up through the stem and leaves, and then evaporate into the air.

The troposphere is the layer of the atmosphere that is closest to the Earth's surface. It extends from the ground up to about 10 kilometers (6 miles) in altitude.

The stratosphere is the layer of the atmosphere that is characterized by a decrease in temperature with increasing altitude. It extends from the top of the troposphere to about 50 kilometers (31 miles) in altitude.

The mesosphere is the layer of the atmosphere that is characterized by a relatively constant temperature. It extends from the top of the stratosphere to about 85 kilometers (53 miles) in altitude.

The thermosphere is the layer of the atmosphere that is characterized by a rapid increase in temperature with increasing altitude. It extends from the top of the mesosphere to the edge of space.

Insolation is the process by which the Earth's surface is heated by the sun's radiation. This occurs when the sun's rays strike the Earth's surface and are absorbed by the land, water, and air.

Radiation is the process by which the Earth's surface releases heat into the atmosphere. This occurs when the Earth's surface emits infrared radiation, which is absorbed by the atmosphere.

Conduction is the process by which heat is transferred from one object to another through direct contact. This occurs when the atoms or molecules of one object collide with the atoms or molecules of another object, transferring heat.

Convection is the process by which heat is transferred from one place to another by the movement of fluids. This occurs when a fluid is heated, causing it to expand and rise, and then cooler fluid moves in to take its place.

Infiltration is the process by which water moves through the soil and into the groundwater. This occurs when water from the surface of the Earth seeps into the soil, where it can be stored and used by plants and animals.