The mountains act as a barrier to eastward-flowing air from the Pacific Ocean. When wet, oceanic air collides with the mountains, it begins to climb. As the rising air goes up and over the mountains, it cools and condenses, generating clouds and precipitation. The clouds then descend the other side of the range back into the Pacific Ocean. This process helps create tropical storms on the other side of the globe.
The presence of mountains also has an effect on the local climate. In areas where there are no obstacles to prevent wind from blowing directly towards the sea, such as the plains of India or China, powerful cyclones can form. But apart from these extreme cases, most mountain ranges tend to cause winds to blow across them, not straight at them. This is because any air that wants to reach the far side of the range must go around it.
There are two main effects of this on the weather: 1 Wind patterns are changed so that rain falls on one side of the range but not the other. 2 The range itself can have a big influence on temperature by blocking heat coming in from the south or west. For example, if a large range crosses an area of warm water, it may freeze over during winter. If a similar range crosses an area of cold water, it may become too cold for snow to fall.
These are just some of the ways that mountains affect the weather and climate.
Winds transport wet air over the terrain. Because the mountains are in the way, air rises as it reaches them. As the air rises, it cools, and because cool air can transport less moisture than warm air, precipitation is common (rain). When winds reach 100 km/hr or more, they become hurricanes.
Mountain ranges can also influence climate by blocking heat from reaching the ocean or blocking moisture-laden storms from reaching the continent. This can have major effects on the surrounding region.
Mountains can also affect climate by causing local changes in temperature and precipitation. The shape of a mountain itself can change the amount of rain that it receives. For example, the rain shadow created by a volcano causes lower levels of pressure at its location, which leads to a decrease in the wind speed necessary to reach cloud top temperatures above the crater. This means that the area around the volcano is likely to see more rainfall than areas without such a barrier.
Finally, mountains can affect climate by preventing heat from escaping into space. An island continent like Europe tends to stay warmer than other parts of the planet because it doesn't have access to large bodies of water that could act as heat sinks.
The effect of mountains on climate is one of the main reasons why we find high concentrations of biodiversity within their boundaries.
Because of the prevalent wind patterns, air is forced to flow up and over the mountain. The air cools as it rises, and the moisture in the air condenses and falls as precipitation. The side of the mountain where the air is driven up receives more precipitation, while the opposing slope remains dry. This is why rain usually falls on the western sides of mountains.
Australia's main geographical feature is a vast array of mountains and hills, which influence the size of its oceans and atmosphere, as well as its weather. The Australian Alps cover a large part of the country's south-eastern corner, and include some of the highest peaks in Australia. They have had a huge impact on the evolution of life in Australia by providing clear skies for plants to grow, allowing animals to move about more freely than they could in cloudy conditions.
The Australian Alps formed as a result of volcanic activity about 20 million years ago. During this time, giant plates moving across Earth's surface collided, pushing up one section of land and pulling down another. As the plate moved away from Australia, it left a deep trench running along its edge. When the plate finally stopped moving, it left a line of hard rock called a "rifting margin". The plate then began moving again, but this time towards Europe, causing Australia to be pulled apart as it went. When the plate reached Europe, it was stopped once more, leaving a similar line of hard rock in both countries.