Assignment Wk3
1. The pressure announced on last night's television weather broadcast was 29.92. Explain how this was measured and give the units. Would this be considered an unusually large or low pressure value?
A pressure announced on the weather forecast of 29.92 is an average measurement. It is measured with a barometer and in the United States the units of measure are inches of mercury, or inHg. This is what meteorologist are referring to in their forecasts. 29.92 inHg is a measurement within the normal range. This may be referred to as air pressure, atmospheric pressure or barometric pressure. They are all the same thing. Low pressure readings are associated with stormy weather and precipitation, while high pressure readings are indicated by clear and calm weather. Here is Portland, Oregon, where it rains 9 months of the year, we experience normal pressure readings of 29.92 inHg or slightly higher or lower. It only changes when we have exceptionally worse or better weather.
2. If the earth did not rotate, how would you expect winds to blow with respect to high and low pressure centers?
With no earth rotation, winds would blow in straight lines. They would move from a huge high pressure region, the side in direct sunlight, to the lowest pressure region. This would be the dark side of the earth. The side the sun never touches. Cold air from the dark side would then be pulled back to the sunny side in straight lines to be warmed and then pushed back again. The dark side would be in a constant state of stormy weather, while the sun side would experience beautiful clear, calm, sunny days. If it didn’t get cooked by the sun, that is.
3. If the pressure gradient force remained the same but the earth's rate of rotation decreased slightly, would you expect the speed of the geostrophic wind to increase, decrease or remain about the same?
If pressure gradient winds remained the same but the earth’s rotation slowed geostrophic winds would increase. The Coriolis force is a force
A pressure announced on the weather forecast of 29.92 is an average measurement. It is measured with a barometer and in the United States the units of measure are inches of mercury, or inHg. This is what meteorologist are referring to in their forecasts. 29.92 inHg is a measurement within the normal range. This may be referred to as air pressure, atmospheric pressure or barometric pressure. They are all the same thing. Low pressure readings are associated with stormy weather and precipitation, while high pressure readings are indicated by clear and calm weather. Here is Portland, Oregon, where it rains 9 months of the year, we experience normal pressure readings of 29.92 inHg or slightly higher or lower. It only changes when we have exceptionally worse or better weather.
2. If the earth did not rotate, how would you expect winds to blow with respect to high and low pressure centers?
With no earth rotation, winds would blow in straight lines. They would move from a huge high pressure region, the side in direct sunlight, to the lowest pressure region. This would be the dark side of the earth. The side the sun never touches. Cold air from the dark side would then be pulled back to the sunny side in straight lines to be warmed and then pushed back again. The dark side would be in a constant state of stormy weather, while the sun side would experience beautiful clear, calm, sunny days. If it didn’t get cooked by the sun, that is.
3. If the pressure gradient force remained the same but the earth's rate of rotation decreased slightly, would you expect the speed of the geostrophic wind to increase, decrease or remain about the same?
If pressure gradient winds remained the same but the earth’s rotation slowed geostrophic winds would increase. The Coriolis force is a force
References: Ahrens, C. D. (01/2014). Essentials of Meteorology: An Invitation to the Atmosphere, 7th Edition [VitalSource Bookshelf version]. Retrieved from http://online.vitalsource.com/books/9781305439733