What does the acronym DALR stand for?

The term DALR stands for "Dry Adiabatic Lapse Rate." This concept is crucial in meteorology and aviation as it describes the rate at which an unsaturated air parcel cools as it rises in the atmosphere. The standard rate is approximately 9.8°C per kilometer (or about 1°C per 100 meters).

In practical terms, understanding the dry adiabatic lapse rate helps pilots and meteorologists predict weather conditions, as it informs them about the behavior of air masses and potential turbulence. When an air parcel rises, it expands due to lower atmospheric pressure, resulting in a decrease in temperature at the dry adiabatic lapse rate until it reaches the saturation point, where condensation may start and lead to different behaviors as moisture becomes involved.

The other options refer to variations or incorrect terminology concerning the lapse rate, but the term "dry adiabatic lapse rate" is the standard and widely accepted acronym and concept in atmospheric science.