Elevation above sea level and temperature are negatively-correlated variables. Which of the following statement describes the relationship between the variables?
A.
As elevation decreases, temperature remains the same
B.
As elevation decreases, temperature decreases
C.
As elevation increases, temperature decreases
D.
As elevation increases, temperature increases
The Correct answer and Explanation is:
The correct answer is C: As elevation increases, temperature decreases.
Explanation:
The relationship between elevation above sea level and temperature is characterized by a negative correlation, meaning that as one variable increases, the other decreases. Specifically, in most geographical locations, as elevation rises, the temperature tends to drop. This phenomenon can be explained by several atmospheric principles.
- Atmospheric Pressure: As elevation increases, the atmospheric pressure decreases. Air at higher altitudes is less dense and cannot hold heat as effectively as denser air found at lower elevations. Consequently, this leads to lower temperatures at higher elevations.
- Lapse Rate: The lapse rate refers to the rate at which temperature decreases with an increase in altitude. On average, the temperature decreases by about 6.5 degrees Celsius for every 1,000 meters of ascent in the troposphere, which is the lowest layer of Earth’s atmosphere. This lapse rate is consistent across various geographic locations, although local conditions may affect it slightly.
- Environmental Factors: Other environmental factors, such as vegetation, urban development, and geographical features, can influence temperatures at different elevations. For example, mountain ranges often experience colder temperatures at their peaks compared to the warmer valleys below.
- Inverse Relationship: The negative correlation implies that the relationship is not simply linear; as one variable increases (elevation), the other variable (temperature) consistently decreases. This consistent pattern can be observed in mountainous regions, where the peaks are often capped with snow while the valleys may have much milder temperatures.
In summary, choice C accurately describes the relationship between elevation and temperature: as elevation increases, temperature decreases, reflecting the fundamental principles of atmospheric science.