a. Do you believe that snow falls only when the temperature is below freezing? Typically, snow does require

Freezing is the process when a liquid turns into a solid due to a decrease in temperature. In the case of snow, it is formed when droplets of water freeze in the atmosphere and fall to the ground as ice crystals.

Typically, snow does require the air temperature to be at or below freezing in order to fall. This means that the temperature of the air should be 0 degrees Celsius or below. When the temperature is too warm, the water droplets will remain in a liquid state and fall as rain instead of snow.

However, there are certain conditions where snow can fall even when the air temperature is slightly above freezing. This phenomenon is known as "wet snow" or "sleet". It occurs when the upper layers of the atmosphere are colder than the surface temperature. In this case, the snowflakes partially melt as they fall through a layer of above-freezing air and refreeze before reaching the ground.

Another scenario where snow can fall at temperatures above freezing is when there is a rapid drop in temperature due to a cold front or a weather system. If it continuously rains in air with a temperature as high as 6 °C, it could lead to a decrease in air temperature that is low enough for the rain to convert into snow. This occurs because rain droplets higher up in the atmosphere can freeze before reaching the ground, resulting in snowfall.

In conclusion, while snowfall typically occurs when the air temperature is at or below freezing, there are instances where snow can fall at temperatures slightly above freezing. These conditions include wet snow or sleet formation and sudden drops in temperature due to weather patterns.