Constructive metamorphosis is caused by the upward movement of water vapor within the snowpack. Warmer temperatures are found closer to the ground because it receives heat from the core of the earth. Snow has a low thermal conductivity, so this heat is retained, creating a temperature gradient between the air underneath the snowpack and the air above it.
Constructive metamorphosis is triggered by the upward movement of water vapor within the snowpack. Warmer temperatures are located closer to the ground due to heat transfer from the Earth's core, resulting in a temperature difference between the air beneath the snowpack and the air above it.