Illustration of Orographic Lift and Rain Shadow Effect
This illustration shows how orographic lift creates zones of high moisture and others of rain shadow. As warm air moves across a body of water, it picks up moisture from the water. As the air is pushed up onto land, and over a mountain range, it rises, and cools. Cooler air can hold less moisture, so condensation forms. This creates regions of high rainfall, with ample clouds and mist, like found in many off the areas that grow tea.
As the air is eventually pushed over the crest of tall mountains, it has little moisture left, and the air reaching the other side of the mountain expands and warms, creating a much lower relative humidity. This dry air causes the rain shadow effect.
This image is featured in our article on Climate, Geography, and Tea Production.