Why do north facing slopes on mountains support glaciers today while south facing slopes do not?

North facing slopes retain some snow all summer and allow glaciers to build up. That is because (in the northern hemisphere) they see less sun.

The reason why north-facing slopes on mountains tend to support glaciers today while south-facing slopes do not is primarily due to differences in exposure to solar radiation and temperature.

Glaciers require specific conditions to form and persist, such as a consistent supply of snowfall and cold temperatures. North-facing slopes receive less direct sunlight throughout the year because they are oriented away from the sun's path. As a result, these slopes experience less solar radiation and, subsequently, remain cooler. This cooler environment helps preserve or even accumulate snow over time, leading to the formation and maintenance of glaciers.

On the contrary, south-facing slopes receive more direct sunlight and are consequently exposed to higher amounts of solar radiation. This exposure to sunlight causes these slopes to warm up more quickly and reach higher temperatures. Higher temperatures lead to a faster melting of snow and ice, making it challenging for glaciers to establish, let alone survive.

To understand why this happens, you can consider the following steps:

1. Identify the factors influencing glacier formation: Glaciers require a consistent supply of snowfall and cold temperatures to form and persist. These factors are influenced by various geographic and climatic conditions.

2. Analyze the impact of slope orientation: Consider the orientation of slopes relative to the sun's path. North-facing slopes receive less direct sunlight, resulting in lower solar radiation and cooler temperatures. In contrast, south-facing slopes receive more direct sunlight, leading to higher solar radiation and warmer temperatures.

3. Examine the effect of temperature on snow and ice: Explore how temperature affects the melting process of snow and ice. Higher temperatures contribute to accelerated melting, leading to a reduction in snow and ice accumulation on south-facing slopes.

4. Connect the dots: By putting these factors together, you can conclude that the reduced solar radiation and cooler temperatures on north-facing slopes create an environment more conducive to glacier formation and preservation, while the higher temperatures on south-facing slopes inhibit glacier growth and often cause them to retreat.

By understanding these principles, we can better comprehend why north-facing slopes on mountains typically support glaciers while south-facing slopes do not.