Atmospheric Temperature Change with Altitude Explained

The question asks to identify the term that describes how the temperature of the atmospheric air changes as altitude increases. Understanding this concept is crucial in meteorology and atmospheric science.

Understanding Temperature Variation with Altitude

As we move upwards through the Earth's atmosphere, the air temperature does not remain constant. It typically decreases in the lower part of the atmosphere (the troposphere). The specific term used to describe this rate of temperature change is:

• Lapse Rate: This is the correct term. The lapse rate defines the rate at which the air temperature decreases with an increase in altitude. The average environmental lapse rate is approximately $6.5^\circ C$ per 1000 meters (or $3.6^\circ F$ per 1000 feet).

Analyzing Other Options

Let's look at why the other options are not the best fit for the question:

• Adiabatic Rate: This term refers to the rate at which a parcel of air changes temperature as it rises or sinks due to expansion or compression solely caused by pressure changes. It does not involve heat exchange with the surrounding environment. While related to atmospheric processes, it's a specific type of temperature change, not the general measurement of temperature change with altitude.
• Isothermal Rate: An isothermal process or rate implies that the temperature remains constant. While some layers of the atmosphere can be nearly isothermal, it is not the general rule describing the overall change of temperature with altitude in the troposphere.
• Global Rate: This is not a standard meteorological term used to describe the change in atmospheric temperature with altitude. It might be misinterpreted as a global average temperature trend, but it doesn't specifically address the vertical change in temperature.

Conclusion on Temperature Change

Based on the definitions, the term that accurately describes the change of atmospheric air temperature with altitude is the Lapse Rate.