AMU SCIN 137 Wk 3
Prof. Wayne MacKenzie
SCIN 137
22 February 2015
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. 29.92 is the standard sea level pressure, identified by inches of Mercury in a barometer, and identifies the pressure over an area using the millibar. This would not be considered a large/low pressure measurement.
2. If the earth did not rotate, how would you expect winds to blow with respect to high and low pressure centers?
a. If there was no rotation of the earth, winds would move directly from low to high pressure areas in a “straight” line. The rotation of the earth is referred to as the Coriolis effect, and in effect, the winds would move in direct lines from higher to lower pressure areas to create equilibrium, however the earth wouldn’t be turning, negating the spiraling effect of the Coriolis effect.
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?
a. If the winds are moving at the same rate from lower to higher. Pressure increases speed increases as winds continue to move from higher to lower pressures, but are moving without a “boost” from the Coriolis effect.
4. Explain why it is much more difficult to measure snowfall amount than rainfall amount.
a. There are a couple conditions that make measuring snow fall more difficult than measuring rain but a major factor is wind; wind easily affects snow fall (drifting). Three or more sites are used to present and average snow fall accumulation measurement, however many remote sensing techniques are predominately used today. Snow accumulation is measured with lasers, GPS, and the melting of snow pack to a water equivalent.
5. Would you expect to find a subsidence inversion to be associated with high or low
SCIN 137
22 February 2015
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. 29.92 is the standard sea level pressure, identified by inches of Mercury in a barometer, and identifies the pressure over an area using the millibar. This would not be considered a large/low pressure measurement.
2. If the earth did not rotate, how would you expect winds to blow with respect to high and low pressure centers?
a. If there was no rotation of the earth, winds would move directly from low to high pressure areas in a “straight” line. The rotation of the earth is referred to as the Coriolis effect, and in effect, the winds would move in direct lines from higher to lower pressure areas to create equilibrium, however the earth wouldn’t be turning, negating the spiraling effect of the Coriolis effect.
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?
a. If the winds are moving at the same rate from lower to higher. Pressure increases speed increases as winds continue to move from higher to lower pressures, but are moving without a “boost” from the Coriolis effect.
4. Explain why it is much more difficult to measure snowfall amount than rainfall amount.
a. There are a couple conditions that make measuring snow fall more difficult than measuring rain but a major factor is wind; wind easily affects snow fall (drifting). Three or more sites are used to present and average snow fall accumulation measurement, however many remote sensing techniques are predominately used today. Snow accumulation is measured with lasers, GPS, and the melting of snow pack to a water equivalent.
5. Would you expect to find a subsidence inversion to be associated with high or low