Lesson 106

Question 1

The pressure difference in the __________ causes air to ________. These pressure differences in the atmosphere are causes by an unequal distribution of ___________ in the atmosphere.

Answer 1

Horizontal

Move

Temperature

Question 2

In the norther hemisphere, as the air moves from a high pressure area to a low pressure area, the _________ force (effect) deflects the air to the _________ . The air flows ________ to the isobars.

Answer 2

Coriolis
Right
Parallel

Question 3

Describe what initiates the movement of air

Answer 3

The pressure difference in the horizontal causes air to move (wind). These pressure differences in the atmosphere a caused by an unequal distribution of temperature in the atmosphere.

Question 4

Define friction force in relation to wind.

Answer 4

The force which results when the wind interacts with the earth’s surface. This results in the coriolis effect being diminished.

Question 5

State the effects of diurnal heating on surface winds.

Answer 5

Over land on a hot summer day, the winds tend to conform to the wind at the 3000’ (1000m) level.
During the night, the surface cooling reduces the eddying motion of the air in the lower levels. Instead of conforming to the 3000’ winds it assumes its normal direction and speed, i.e. it BACKS and DECREASES. With daytime heating the wind will veer and increase.

Question 6

The greater the effect of surface friction, the _________ the angle of the surface wind to the isobars and the _________ its speed.

Answer 6

Greater

Less

Question 7

The diurnal change of surface wind speed and direction is such that the wind tends to veer and _________ by _________ and back and _________ by _________.

Answer 7

Increase by day

Decrease by night

Question 8

Gusts are often associated rapid changes in wind direction that are caused mainly by what two ways:

Answer 8

Mechanical turbulence

Unequal heating of the earth’s surface (can create convective cloud creating downdrafts/gusts).

Question 9

What are the two principal causes of squalls.

Answer 9

Well developed thunderstorms

Fast moving cold fronts

Question 10

Katabatic winds are winds which blow down ice-free slopes only ________ .

Answer 10

At night

Question 11

Sea breezes blow from ________ by ________ and are caused by:

Answer 11

Water
Day
Warm land causes low pressure which allows the higher pressure air over the water to flow towards land.