What is indicated by a temperature decrease of 2 degrees Celsius at an altitude increase of 1000'?

A temperature decrease of 2 degrees Celsius with an altitude increase of 1,000 feet suggests a normal lapse rate. In the atmosphere, the normal lapse rate occurs when air temperature decreases as altitude increases, typically at a rate of about 6.5 degrees Celsius for every 1,000 meters (or approximately 3.6 degrees Fahrenheit for every 1,000 feet).

A decrease of 2 degrees Celsius for every 1,000 feet aligns closely with this expected range, indicating that the atmosphere is behaving in a typical manner. This normal lapse rate is indicative of stable atmospheric conditions where vertical movements of air are limited, although specific stability judgments would require additional information about humidity and other factors.

In contrast, an inversion layer would show an increase in temperature with altitude, which would not fit the scenario presented. Similarly, a stable atmosphere or unstable weather conditions typically reflect different patterns of temperature change and air movement, adding another layer of context that the given temperature change does not exhibit. Thus, the observed temperature decrease aligns with the definition of a normal lapse rate.