format of weather
Terms
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- 3 vertical circulations of air
- hadley cell, farrel cell, and polar cell
- 2 scales to measure temperature
- celius and fahrenheit scales
- temperature
- the amount of heat in the atmosphere; how hot or cold we feel is also affected by humidity and wind speed
- dewpoint
- reflects the water vapor content in the air and that water vapor influences the natural cooling mechanism of our bodies
- sling psychrometer
- instrument that measures relative humidity
- condensation
- when water vapor gas changes into actual droplets of water
- heat stroke
- when body temp. reaches 106 degrees and the body comnpletely shuts down - it can be fatal
- control the behavior of weather
- temperature, moisture, pressure
- aneroid bar
- a little box within the instrument will expand or contract when the pressure around it increases or decreases as volume changes a dial moves right or left showing the pressure
- polar cell
- lies between poles and 60 degrees north and south
- 2 kinds of bars
- aneroid bar and mercorial barometer
- heat exhaustion
- fatigue, headache, nausea, fainting caused by additional water loss
- celsius
- scale used in most countries, introduced by Swedish astronomer Andres Celsius in 1742
- humidity
- determined by temperature (The temperature of the air determines the amount of water vapor it can hold. The warmer the air - the more the vapor. when air can hold no more water it is saturated
- fahrenheit
- based on the major points of 0 degrees which was the lowest temperature people could produce then and 96 degrees was what Gabriel Fahrenheit assumed to be the temperature. On this scale freezing point of water is 32 degrees and the boiling point of water in 212 degrees
- dewpoint readings
- 60s - moderately comfortable, 70s - very uncomfortable, 80s - tough to breathe
- wind
- when air moves above the rotating earth - develops because of differences in atmospheric pressure
- 2 ways to express humidity
- relative humidity and absolute humidity
- high pressure
- a sunny day (because sinking air = no moisture can rise = no clouds = clear sky
- relative humidity
- is the absolute humisity divided by the amount of water that could be present in the air and is expressed in percentages. As the air temp. goes up, the relative humidity goes down
- fahrenheit
- scale still used in U.S. and Britain introduced by German scientist Gabriel Fahrenheit in 1714
- dewpoint temperature
- temperature at which saturation occurs. It is used to help predict the occurence of cluds)
- the earths surface pressure is new
- the atmosphere is lifted away
- absolute humidity
- the quality of water vapor in a given amount of air at the current temperature and is also the percentage of water vapor actually present in the air
- wet bulb
- is surrounded by wet muslin and measures the temp. of the saturated air
- sweating
- when sweat glands release water in the form of perspiration. When the moisture evaporates we cool down because the process of evaporation extracts heat.
- coriolis force
- a force named for Gaspard Coriolis, a 19th century French scientist who figured out why weather systems spin. This force is because the earth is in motion.
- convergence
- air comes together at a particular location - stormy weather
- atmospheric pressure
- caused by the weight of the air = 15 pounds per square inch
- heat cramps
- caused when hot weather results in rapid water and salt loss causing a chemical imbalance that leads to cramps
- dry bulb
- measures actual air temp.
- humidity
- the quantity of water vapor in the air
- in northern hemisphere
- high pressure areas spin clockwise (opposite in southern hemisphere)
- relative humidity
- a measure of the quantity of moisture in the air relative to the quantity needed to saturate the air at that temp.
- farrel cell
- occurs 30 to 60 degrees north and south
- coriolis effect
- the rotation of the earth causing moving objects such as winds and ocean currents to be deflected. So it affects wind direction and the direction of air
- divergence
- more air leaves than arrives - sunny day
- hadley cell
- 30 degrees north and south of equator
- low pressure
- stormy weather
- mercorial barometer
- has mercury in a graduated glass tube
- bar
- basic unit of pressure