The "tallness" of clouds, or their vertical extent, is largely determined by atmospheric conditions, specifically moisture content and temperature.
Here's a breakdown:
-
Vertical Air Currents (Convection): Clouds form when warm, moist air rises. If the atmosphere is unstable (i.e., the rising air remains warmer than its surroundings), this air will continue to rise, potentially creating a very tall cloud. This is the primary driver.
-
Moisture Content: In humid environments, there's abundant moisture readily available for condensation as the air rises and cools. This allows clouds to grow vertically to a greater extent because there is a continuous supply of water vapor fueling their development.
-
Temperature Gradients: A significant temperature difference between the ground and higher altitudes promotes strong updrafts. These updrafts lift the moist air to greater heights, leading to taller clouds.
-
Atmospheric Stability: Stable air resists vertical movement, preventing clouds from growing tall. Unstable air, on the other hand, allows for significant vertical development.
-
Types of Clouds: Certain types of clouds, like cumulonimbus clouds (thunderstorm clouds), are known for their exceptional vertical development. These clouds can extend through a significant portion of the troposphere (the lowest layer of the atmosphere).
The Washington Post article cited mentions how cloud base height varies depending on climate, not necessarily cloud height. While a drier climate will typically have higher cloud bases because the air needs to rise higher to cool to its dew point, the mechanisms determining the vertical extent of a cloud are predominantly related to atmospheric instability and moisture content.
