Question 1

What is an example of microscale motion?

Accepted Answer

Microscale motion refers to the smallest scale of atmospheric motions, typically involving movements over short distances and short periods of time, such as winds blowing past a chimney. This contrasts with larger scale motions like those seen in weather maps or global wind patterns.

Question 2

Compressional heating is the main source of warmth for a Chinook wind.

Accepted Answer

Chinook winds are warm, dry winds that occur on the leeward side of mountain ranges. They are primarily warmed through compressional heating, which happens as air descends from the mountains into lower elevations, increasing in temperature as the pressure increases.

Question 3

Wind direction and speed can be determined with an aerovane.

Accepted Answer

An aerovane, also known as a wind vane or weather vane, is designed to point in the direction from which the wind is coming and can be equipped with anemometer cups to measure wind speed, thus determining both wind direction and speed.

Question 4

Strong winds blowing over vegetation results in rapid water loss in the plant.

Accepted Answer

Strong winds increase the rate of transpiration by removing the boundary layer of still air that surrounds the leaves, leading to more rapid water loss from the plant.

Question 5

What is an example of mesoscale motion?

Accepted Answer

Mesoscale motion refers to atmospheric motions on a scale smaller than synoptic (weather map scale) but larger than microscale (immediate vicinity, like around a chimney). Winds blowing through a city fit this definition, as they are influenced by the urban layout and buildings, but cover a larger area than immediate obstacles.

Question 6

Sand ripples can indicate the prevailing wind direction in an area.

Accepted Answer

Sand ripples are formed by the wind blowing across loose sand, creating patterns that align perpendicular to the prevailing wind direction. This means the orientation of sand ripples can be used to infer the dominant wind direction in an area.

Question 7

Microscale circulations range from a few kilometers to about a hundred kilometers in diameter.

Accepted Answer

Microscale circulations typically range from less than a meter to a few kilometers in diameter, not up to a hundred kilometers.

Question 8

Clear air turbulence often occurs near a boundary of high wind shear.

Accepted Answer

Clear air turbulence often occurs near boundaries where there is a significant change in wind speed or direction over a short distance, known as high wind shear areas. This can happen without visual cues like clouds, making it hard to predict or see.

Question 9

Thermal lows form in response to variations in surface air temperature.

Accepted Answer

Thermal lows form due to intense heating of the Earth's surface, which causes the air above it to warm, expand, and rise, leading to a decrease in surface air pressure and the formation of a low-pressure area.

Question 10

In city planning, sewage disposal plants must be situated upwind from large housing developments.

Accepted Answer

Sewage disposal plants are typically situated downwind from large housing developments to minimize the exposure of residents to unpleasant odors.

Question 11

The airflow on a sand dune is strongest at the top of the dune.

Accepted Answer

The airflow is strongest at the top of a sand dune because it is the highest point, where wind speeds are typically greater due to less obstruction and increased exposure.

Question 12

Which association is most accurate?

Accepted Answer

Mesoscale meteorological phenomena are smaller than synoptic scale (weather systems) but larger than microscale (turbulence, small eddies) phenomena, typically ranging from about 2 km to about 2000 km. A land breeze, which occurs due to temperature differences between land and sea at night, fits within this scale.

Question 13

In the northeastern half of the United States, the prevailing wind in winter is southwest and in summer it is northwest.

Accepted Answer

In the northeastern United States, the prevailing winter wind is generally from the northwest, while in summer, it tends to come from the southwest. This pattern is influenced by the seasonal shifts in the jet stream and the distribution of high and low pressure systems.

Question 14

The difference in surface wind speed between morning and afternoon is typically greater on a clear, sunny day than on a cloudy, overcast day.

Accepted Answer

On clear, sunny days, the ground heats up more than on cloudy, overcast days, leading to stronger thermal updrafts and greater differences in surface wind speeds between morning and afternoon.

Question 15

Thermal lows become weaker with increasing height.

Accepted Answer

Thermal lows, which are areas of low pressure formed due to intense heating at the surface, tend to weaken with increasing altitude because the air cools as it rises, reducing the intensity of the low-pressure system.

Question 16

Friction is not restricted to solid objects; it occurs in moving fluids as well.

Accepted Answer

Friction in fluids is known as viscosity, which is the resistance of a fluid to flow and is a form of friction that occurs between fluid layers as well as between the fluid and any solid surfaces it is in contact with.

Question 17

Prevailing offshore winds in summer carry moisture, cool air, and fog into coastal regions, whereas prevailing onshore breezes carry warmer and drier air into the same locations.

Accepted Answer

Prevailing offshore winds carry warmer and drier air away from coastal regions, while onshore breezes bring moisture, cool air, and often fog into coastal areas.

Question 18

A valley breeze develops its maximum strength in the early afternoon.

Accepted Answer

A valley breeze reaches its maximum strength during the early afternoon because the sun heats the valley floors and slopes, causing the air to warm, become less dense, and rise, creating an upslope wind.

Question 19

The amount of energy transferred to the water (and thus the height to which a wave can build)depends upon four factors: 
1. wind speed 
2. length of time that the wind blows over the water 
3. the fetch 
4. wind direction.

Accepted Answer

The amount of energy transferred to the water and the height to which a wave can build depend on three main factors: wind speed, length of time the wind blows over the water, and the fetch (the distance over which the wind blows across the water). Wind direction affects the direction of wave travel but not the energy transferred to the water or the height of the wave.

Question 20

Coastal areas can have heavy waves on a clear, nonstormy day.

Accepted Answer

Coastal areas can experience heavy waves due to distant storms or swells that travel long distances across the ocean, affecting shores even on clear, nonstormy days.

Quiz 9: Wind: Small-Scale and Local Systems