Thursday, 3 July 2014

Lit review (Kenric)

ISS lit review

According to Walter (2001), the pressure in the air is affected by the different chemical elements in the air with different atomic weights. As air normally weighs 1.286 grams per litre and water vapour weighs 0.8 grams per litre, if some of the air was substituted for water, the mixture becomes lighter. So, if there's water (otherwise known as humidity) in the air, the air mixture becomes lighter, reducing the air pressure in the atmosphere (Walter, 2001).

(HowsStuffWorks) Humidity is the percentage of water vapour in the air and it also affects the air pressure as shown above. Humidity can be measured in many different ways, but relative humidity is the most common. Relative humidity is the ratio of the current absolute humidity to the highest possible absolute humidity (which depends on the current air temperature). Absolute humidity is the mass of water vapor divided by the mass of dry air in a volume of air at a given temperature. The warmer the air is, the more water vapour it can contain. A reading of 100% relative humidity means that the air is totally saturated with water vapor and cannot hold any more, creating a high possibility of rain. This doesn't mean that the relative humidity must be 100 percent in order for it to rain -- it must be 100 percent where the clouds are forming, but the relative humidity near the ground could be much less (HowStuffWorks, 2014). 

(Aubyn)Air temperature affects the weather in a huge way as it affects the air’s humidity. The more humid the air is means the air can become warmer and this will ultimately cause weather conditions such as thunderstorms and hurricanes. The way in which cold and warm air interacts is what makes us get different weather conditions. 
The thing that affects the heat of the air and the land is the sun.  The more intense the rays of the sun, the more heat there is in the air. As the air rises up into the atmosphere, its temperature will fall and this is what causes clouds. If more and more moisture is taken in by the clouds, this is what causes precipitation that can fall in the form of rain, sleet, snow or hail.
When cold and warm temperature masses meet, this is what causes different weather conditions. So for instance, when a cold air mass moves into a warm air mass the cold air will contract. This will then cause the cold air to become denser and heavier than the warm air so it is pushed out underneath the warm air. This type of activity is what causes conditions such as thunderstorms. The air will probably become cooler too as the sky begins to clear from the fronts moving on. 
On the opposite side, when a warm air front moves into a cold one, this will cause the warm air to rise as it is not as dense or as heavy as the cold air. This may cause some form of precipitation which falls on the land as snow or rain. There are also the occasions where the cold and warm air fronts remainstationary and do not move. As a result of this, there will probably be some precipitation and weak winds (Aubyn).

(Waikatoregion) The weather and local climate affect air quality. Air pollution can change hourly depending on changes in weather patterns, location and the pollutants being emitted.What the weather is doing can have direct effects on air quality at a given location. For example, sunshine, rain, air temperature and wind can affect the amount of air pollution present. Sunshine makes some pollutants undergo chemical reactions, producing smog while rain washes out water soluble pollutants and particulate matter. Higher air temperatures speed up chemical reactions in the air and wind speed, atmospheric turbulence/stability, and mixing depth - affect the dispersal and dilution of pollutants. The weather can also affect air pollution by affecting people’s activities.
For example, in cold weather we tend to light more fires - for home heating, travel to work in motorised forms of transport more often. In warm weather we tend to use barbecues more often and go away for weekend trips or holidays using motor vehicles. the examples shown release pollutants too (Waikatoregion).

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