FREE CBM Atmospheric Thermodynamics Questions and Answers

Question 1

What is the dry adiabatic lapse rate approximately?

Accepted Answer

9.8°C/km

Answer

The dry adiabatic lapse rate (DALR) is the rate at which an unsaturated parcel of air cools as it rises, or warms as it descends, due to adiabatic expansion or compression. This rate is approximately 9.8°C per kilometer (or 5.5°F per 1000 feet). It's a fundamental concept in atmospheric thermodynamics, describing temperature changes without heat exchange with the surroundings.

Question 2

What happens to an air parcel as it rises in the atmosphere?

Accepted Answer

Expands and cools

Answer

As an air parcel rises in the atmosphere, the surrounding atmospheric pressure decreases. This lower pressure allows the air parcel to expand. The expansion requires the parcel to do work on its surroundings, which uses up some of its internal energy, resulting in a decrease in its temperature (adiabatic cooling).

Question 3

Which term describes the temperature at which air becomes saturated?

Accepted Answer

Dew point

Answer

The dew point is the temperature to which air must be cooled at constant pressure and water content for saturation to occur. When the air temperature drops to the dew point, water vapor begins to condense into liquid water, forming dew, fog, or clouds. It's a key indicator of atmospheric moisture content and potential for precipitation.

Question 4

Which process releases latent heat into the atmosphere?

Accepted Answer

Condensation

Answer

Condensation is the process where water vapor changes into liquid water. During this phase change, latent heat (energy stored in the water vapor) is released into the surrounding atmosphere. This release of latent heat is a significant energy source for atmospheric processes, including the development and intensification of thunderstorms and hurricanes.

Question 5

What does a negative lifted index (LI) indicate?

Accepted Answer

Unstable air

Answer

The Lifted Index (LI) is a common stability index used in meteorology to assess the potential for thunderstorms. A negative LI value indicates that a parcel of air lifted from the surface would be warmer than the surrounding environment at a given altitude. This temperature difference signifies unstable air, meaning it will continue to rise on its own, favoring the development of convection and severe weather.

CBM - Certified Broadcast Meteorologist Practice Test

CBM - Certified Broadcast Meteorologist Practice Test

FREE CBM Atmospheric Thermodynamics Questions and Answers