Nota Terkini

Wednesday, July 08, 2009

[Science Form 1] Other Components Of Air

The air in our atmosphere has some variable components to it as well. These variable components include water vapour, dust particles, and ozone. Although these are found in small amounts, they can have significant effects on weather and climate.

Water Vapour
The amount of water in the atmosphere varies between 1% to 4%. Why is such a small amount such a big deal? Water vapour is the source of all clouds and precipitation, and often that is the most common reason people think of for water. But water does other things too. It has the ability, like carbon dioxide, to absorb heat energy given off by the earth. It can also absorb solar energy. When water changes from one state to another, it absorbs or releases heat. This heat is often called latent (hidden) heat. This is the energy source that helps drives a lot of storms.

Dust is much more than just little specks of dirt. It includes microscopic particles that are invisible to the naked eye, including pollen, spores, and seeds. So why is dust a big deal? It acts as surfaces where water can condense or group together, forming clouds from which water droplets can grow large and fall to the ground as snow or rain. Without dust, you could not have clouds or fog. Dust can also absorb or reflect incoming solar radiation. When dust in the atmosphere is high, such as during the haze, the amount of sunlight reaching the earth's surface will decrease. Dust can also contribute to scattering light, giving rise to more orange and red sunrises or sunsets.

Other Gases
Methane, sulfur dioxide, hydrogen, nitrous oxide, nitrogen dioxide, iodine, carbon monoxide, ammonia.

Bacteria, fungi, viruses.

Ozone is a form of oxygen that combines three oxygeb atoms into one molecule (O3). There is very little of this gas in the atmosphere, and it is concentrated in the stratosphere. Ozone absorbs ultraviolet (UV) radiation, and without it the earth would be uninhabitable. There may be other components depending on the quality or condition of the air.

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