Chapter 10 - Wind

Question 1

How is surface wind measured

Answer 1

By an Anemometer 10m above the ground

Question 2

What is calm winds

Answer 2

1 knot or less

Question 3

What is a Lull

Answer 3

A sudden drop in wind

Question 4

What is a Gust

Answer 4

Sudden increase in wind 10 knots

Question 5

gale =

Answer 5

43-47 knots

Question 6

storm =

Answer 6

48 - 63 knots

Question 7

Hurricane =

Answer 7

64 +

Question 8

which north are runways aligned with

Answer 8

Magnetic

Question 9

Squall =

Answer 9

An increase of wind that last more than a minute

Question 10

Met reports use which north

Answer 10

True

Question 11

ATC (ATIS) reports use which north

Answer 11

Magnetic

Question 12

Wind moving clockwise is called

Answer 12

Veering

Question 13

Wind moving anti clockwise is called

Answer 13

Backing

Question 14

If isobars are close together which wind does it indicate?

Answer 14

Strong

Question 15

Wind speed is directly proportional to? It also cause air to move from high to low pressure

Answer 15

Pressure Force Gradient

Question 16

Where in the world is the Coriolis effect least?

Answer 16

Equator

Question 17

Which way does the Coriolis effect deflect in the Northern hemisphere

Answer 17

Right

Question 18

Which way does the Coriolis effect deflect in the Southern hemisphere

Answer 18

Left

Question 19

Increase in Latitude (towards the poles) does what to the Coriolis effect?

Answer 19

increases

Question 20

Geostrophic Wind is

Answer 20

When air is moving from H to L and is effected by the Coriolis effect.
The PGF and Coriolis combined when they are equal and opposite to change the wind direction to line up with the straight ISO bars

Question 21

Gradient Wind is

Answer 21

PGF, CF and centrifugal force combine to create curved ISO bars.
Because the centrifugal force is opposing the CF it causes the wind to follow the ISO bars around a depression or high.

Question 22

Surface Wind is and happens where?

Answer 22

In the friction layer (less 1000m) and causes the CF effect to reduce because of the stronger frictional forces near the surface.

Question 23

Surface friction is increase by

Answer 23

Thermal activity making turbulent air. Increases with Diurnal Variation / during the daytime

Question 24

Over the sea the Deflection and % of surface speed is

Answer 24

10 degrees

70%

Question 25

Over land by day the Deflection and % of surface speed is

Answer 25

30 degrees | 50%

Question 26

Over land by night the Deflection and % of surface speed is

Answer 26

45 degrees | 25%

Question 27

In the northern hemisphere when climbing the wind will?

Answer 27

Increase and Veer

Question 28

In the northern hemisphere when descending the wind will?

Answer 28

Decrease and back

Question 29

On a Low Px what will the wind always do

Answer 29

Cut in

Question 30

What is a Sea Breeze

Answer 30

Happens on a sunny day with no clouds the land heats the air and creates a low pressure the air rises and creates a high and diverse away back to the sea and then sinks again low px causes a breeze from the sea to the land

Question 31

Where does the sea breeze happen and what wind speed

Answer 31

During the day 10-15 NM in land speed 10 knots

Question 32

How does a land breeze happen and what are the typical figures

Answer 32

reverse of sea breeze 5 NM 5 Knots

Question 33

Anabatic Winds happen how

Answer 33

Sun heats the surface of a mountain that heated air then rises up the mountain creates a low px at the bottom

Question 34

A valley wind is created how and give a typical one

Answer 34

From the Anabatic winds leaving Low Px in the valley By mid afternoon it causes more air to converge to replace the missing air creating winds Mistral 70 knots

Question 35

Katabatic winds is created how

Answer 35

At night the cold mountain side cools the air Cold air sinking down the mountain Creates a high pressure

Question 36

Mountain winds at night is created how and give a typical one

Answer 36

High pressure is created because of the Katabatic Diverges the air away Bora - in winter up to 100 knots

Question 37

Mistral is a valley wind that flows out of

Answer 37

Rhone Valley into Med (can reach 70 knots)

Question 38

Foehn Wind is found where

Answer 38

In the Alps Get cloud cap on top of the mountain on the Lee side will get warm dry air

Question 39

What is Foehn wind called in the Rockies

Answer 39

Chinook

Question 40

x3 African winds called Sirocco, Ghibli and Khamsin come from which direction and bring what condition

Answer 40

Southerly Dry, Dusty, Wind and air Creating a low pressure over the Med

Question 41

Strong winds and uneven surfaces =

Answer 41

Mechanical/ frictional turbulence

Question 42

Mountain waves/ standing waves/ Lee waves require x3 things

Answer 42

Mountain 15 - 20 knots wind at the top stable air on the Lee side with unstable air above or below

Question 43

How far downwind can the mountain waves occur

Answer 43

50-100NM

Question 44

Give the downwind distances for Pennines Rockies Andes

Answer 44

250 300 500

Question 45

Which clouds do you get with mountain waves

Answer 45

Cap cloud Roll / rotor lenticular

Question 46

Cold Katabatic wind over the Adriatic?

Answer 46

Bora

Question 47

x4 examples of Topographic windshear

Answer 47

Buildings Trees funnelling mountains

Question 48

Horse latitudes are where

Answer 48

Sub tropical highs

Question 49

NE/SE trade winds are from where and heading to

Answer 49

subtropical highs and heading to the lows

Question 50

Doldrums (forms at the ITCZ) what are the winds like

Answer 50

Calm because the two winds don't converge right at the surface

Question 51

Westerlies appear where

Answer 51

Midlatitude lows

Question 52

Polar easterlies come from

Answer 52

The polar highs

Question 53

Harmattan is NE trade wind what condition are usual for it

Answer 53

dry dusty visibility effected 10-15,000 feet

Question 54

Pampero is what

Answer 54

A burst of cold air that crosses the pampas with strong winds oct-jan