Climate has profound effects on us, and the world in which we live. In turn we as humans, and many other global factors contribute to our climate. Almost everything in our lives somehow impacts or is impacted by climate.
We as humans can affect everything, from the food we eat to the air we breathe, including climate. This is through the alteration of the earth?s surface and the introduction of pollutants and chemicals such as carbon dioxide into the atmosphere. The simple but harmful act of clear-cutting can also have a subtle but important role in climate. Tree?s and living plants absorb the carbon dioxide and gases found in our atmosphere, which reduce the amount of solar radiation reaching earth. This effect is most evident in large cities where pollution is prevalent, or the rainforests where clear cutting is rampant.
Our atmosphere is like a greenhouse. The oceans and land masses absorb heat from the sun and emit it slowly, keeping our climate relatively warm. The further (or higher) we move away from the earth, the cooler it gets. Since we are really moving away from the source of the heat, the earth. The atmosphere?s ability to retain heat is known as the greenhouse effect. Without this simple factor in climate we would be living with -18? C climate. Thus, eliminating many species who would be unable to survive in that cold a temperature. Cities such as La Paz, Bolivia stay cold all year long due to their high altitudes, excluding the fact that they are relatively close to the equator.
The atmosphere also moderates the difference in temperature between day and night, so we don?t get extremes of hot and cold. This is particularly critical to the Arctic and Antarctic circles, which experience very long days in summer and equally long nights in winter.
The distance north or south from the equator, or latitude, drastically affects us and our climate. Regions farther north or south of the equator receive less direct sunlight than regions nearer the equator. At more distant locations, the sun?s rays hit the earth at an angle, causing the rays to be dispersed. Latitude also affects the position of the sun in the sky. The amount of sunlight that reaches the earth?s surface also depends on the earth?s tilt. Seasonal weather changes, and changes in day length are directly related to the earth?s tilt as well. Portoviejo, Ecuador, 1? south of the equator receives very direct sunlight causing it to have a warmer climate than places such as Kaujuitoq, Canada 75? north of the equator.
Oceans are highly efficient storers of heat. They transport warm or cool water around the earth and have a great influence on the climate of land masses. These currents are mainly caused by prevailing winds. The winds from the high-pressure systems in the mid-latitudes drive the ocean currents that circulate in a counterclockwise direction in the Southern Hemisphere and clockwise in the north. The warming effects of the Gulf Stream greatly moderate the climate of western Europe, which would otherwise be much more severe.
Two rapidly moving tube-like streams of air in each hemisphere, known as jet streams, work their ways through the upper parts of the troposphere. They are like ocean currents, except in our upper atmosphere. Jet streams are caused by strong temperature and pressure changes in this part of the atmosphere. The polar jet stream enables the warm tropic air to stay in the tropic area?s and the cold arctic area to stay in arctic area?s.
When the sun radiates it?s energy onto the earth, the land is warmed faster than the water. When these currents shift they move the cool water air onto the land, keeping the days cooler. At night, when the sun has set, the water holds the sun?s heat longer than the land, shifting warm winds onto the land, keeping the nights warmer. These winds are called prevailing winds and are important to balance the day and night temperatures of coastal areas. Oceans and lakes also balance the seasonal temperatures of an area. They allow marine areas to stay cooler in the summer and milder in the winter. Most coastal areas show these signs including Vancouver Island, Canada and Cape Cod, Massachusetts.
An air mass is a body of air in which temperature and humidity remain constant. They can range in size from a few miles across to thousands of square miles in area. The general circulation of the atmosphere moves air masses around. A cold front occurs when a mass of cold air drives into a warm air mass. The warm air rises and forms cumuliform clouds causing a sudden change in local weather. Warm fronts form when warm air rides over the top of a mass of cold air, resulting in stratiform clouds, and minor weather changes. These air masses are common in mid-high latitudes and are almost permanent in areas near the equator.
When air travels over a landmass, several processes can occur. If the air was heated by contact with warmer ground, convection might begin, this could produce clouds and rain. The air may lose moisture if mixes with air that has a lower relative humidity. Or Orographic Precipitation may occur. This is when rain is forced down on the windward side of mountains. The rising air cools, and when the vapour condenses clouds form. Next, rain falls before it makes it over the mountains. Once on the leeward side of the mountains the descending air, which is now warming, picks up moisture. This is also known as a Rain-Shadow effect. The Coast Range in between us and Vancouver acts as the mountains explained above. This explains Vancouver?s large amount of rainfall and Oliver?s lack of it.
From people living in the Equatorial Rainforests, to the Inuit of the far north we are all affected by climate. Even though we cannot control it we do affect it. Simply through our day to day lifestyles we, ourselves add to the changing climate. The exhaust from our vehicles to the smoke from our fire places, decimation of the worlds forests to the use of our hair sprays, all contribute. Although, the earth and it?s atmosphere still have the upper force in controlling our climate.