what is the coriolis effect?
Post on 08-Feb-2016
80 Views
Preview:
DESCRIPTION
TRANSCRIPT
WHAT IS THE CORIOLIS EFFECT?
The Apparent Deflection of Objects Moving Across the Surface of the Earth from Their
Intended Path.
Derives from objects (air) passing across a moving frame of reference
(the rotating latitude longitude grid of the world)
Instructions:Cut along dotted line!
Earth Rotating inanti-clockwise direction
Circumference at Equator: 40,077km (24,905 miles).
Rotates once per 24 hrs, thus linear velocity = 40,077/24 = 1670 km. hr-1 (1041 mph)
0° 40077km 1670 km.hr-1
Lat. Circum. Velocity
0° 40077km 1670 km.hr-1
10° 39548km 1648 km.hr-1
Lat. Circum. Velocity
0° 40077km 1670 km.hr-1
10° 39548km 1648 km.hr-1
20° 37771km 1574 km.hr-1
Lat. Circum. Velocity
0° 40077km 1670 km.hr-1
10° 39548km 1648 km.hr-1
20° 37771km 1574 km.hr-130° 34797km 1450 km.hr-1
Lat. Circum. Velocity
0° 40077km 1670 km.hr-1
10° 39548km 1648 km.hr-1
20° 37771km 1574 km.hr-130° 34797km 1450 km.hr-1
40° 30819km 1284 km.hr-1
Lat. Circum. Velocity
0° 40077km 1670 km.hr-1
10° 39548km 1648 km.hr-1
20° 37771km 1574 km.hr-130° 34797km 1450 km.hr-1
40° 30819km 1284 km.hr-1
50° 25876km 1078 km.hr-1
Lat. Circum. Velocity
0° 40077km 1670 km.hr-1
10° 39548km 1648 km.hr-1
20° 37771km 1574 km.hr-130° 34797km 1450 km.hr-1
40° 30819km 1284 km.hr-1
50° 25876km 1078 km.hr-1
60° 20121km 838 km.hr-1
Lat. Circum. Velocity
0° 40077km 1670 km.hr-1
10° 39548km 1648 km.hr-1
20° 37771km 1574 km.hr-130° 34797km 1450 km.hr-1
40° 30819km 1284 km.hr-1
50° 25876km 1078 km.hr-1
60° 20121km 838 km.hr-1
70° 13749km 573 km.hr-1
Lat. Circum. Velocity
0° 40077km 1670 km.hr-1
10° 39548km 1648 km.hr-1
20° 37771km 1574 km.hr-130° 34797km 1450 km.hr-1
40° 30819km 1284 km.hr-1
50° 25876km 1078 km.hr-1
60° 20121km 838 km.hr-1
70° 13749km 573 km.hr-1
80° 6990km 291 km.hr-1
Lat. Circum. Velocity
0° 40077km 1670 km.hr-1
10° 39548km 1648 km.hr-1
20° 37771km 1574 km.hr-130° 34797km 1450 km.hr-1
40° 30819km 1284 km.hr-1
50° 25876km 1078 km.hr-1
60° 20121km 838 km.hr-1
70° 13749km 573 km.hr-1
80° 6990km 291 km.hr-1
Lat. Circum. Velocity
All latitudes rotate with the same ANGULAR VELOCITY (360°/24hrs)15°.hr-1.
However LINEAR VELOCITIES change with latitude.
Rudolf’s View of half a Year’s Work!
Earth Rotating inanti-clockwise direction
Trees are fixed frame of reference
Merry-go-round is moving frame of reference
Merry-go-round is rotating in anti-clockwise direction.
Person in center of merry-go-round throws purple ball towards friend (red) on the merry-go-round
Like Earth rotating inanti-clockwise direction
Moving frame of reference.
Fixed frame of reference
Moving frame of reference.
Fixed frame of reference
Moving frame of reference.
Fixed frame of reference
Moving frame of reference.
Fixed frame of reference
Moving frame of reference.
Fixed frame of reference
Moving frame of reference.
Fixed frame of reference
CORIOLIS EFFECT
• Objects moving across the surface of the Earth in the North hemisphere appear to be deflected to the right of their intended path.
CORIOLIS EFFECT
• Objects moving across the surface of the Earth in the North hemisphere appear to be deflected to the right of their intended path.
• Objects moving across the surface of the Earth in the South hemisphere appear to be deflected to the left of their intended path.
CORIOLIS EFFECT
• Objects moving across the surface of the Earth in the North hemisphere appear to be deflected to the right of their intended path.
• Objects moving across the surface of the Earth in the (?)South hemisphere appear to be deflected to the left of their intended path.
IS THE CORIOLIS EFFECT A GEOGRAPHIC VARIABLE?
Does its effect vary over the surface of the Earth?
4000
2000
3000
1000
01000 2000 3000 4000
10°N, San José
10° Very small decrease in radius. (& linear velocity)
4000
2000
3000
1000
01000 2000 3000 4000
10°N, San José
20°
Slightly larger decrease in radius. (& linear velocity)
20°N, Guantanamo
4000
2000
3000
1000
01000 2000 3000 4000
10°N, San José
30°
Slightly larger decrease in radius. (& linear velocity)
20°N, Guantanamo
30°N, Gainesville
4000
2000
3000
1000
01000 2000 3000 4000
10°N, San José
40°
Slightly larger decrease in radius. (& linear velocity)
20°N, Guantanamo
30°N, Gainesville
40°N, Philadelphia
4000
2000
3000
1000
01000 2000 3000 4000
10°N, San José
50°
Larger decrease in radius. (& linear velocity)
20°N, Guantanamo
30°N, Gainesville
40°N, Philadelphia
50°N, Southampton
4000
2000
3000
1000
01000 2000 3000 4000
10°N, San José
60°
Large decrease in radius. (& linear velocity)
20°N, Guantanamo
30°N, Gainesville
40°N, Philadelphia
50°N, Southampton
60°N, Reykjavik
4000
2000
3000
1000
01000 2000 3000 4000
10°N, San José
70°
Large decrease in radius. (& linear velocity)
20°N, Guantanamo
30°N, Gainesville
40°N, Philadelphia
50°N, Southampton
60°N, Reykjavik70°N
4000
2000
3000
1000
01000 2000 3000 4000
10°N, San José
80°
Large decrease in radius. (& linear velocity)
20°N, Guantanamo
30°N, Gainesville
40°N, Philadelphia
50°N, Southampton
60°N, Reykjavik70°N
80°N
4000
2000
3000
1000
01000 2000 3000 4000
10°N, San José90°
Largest decrease in radius. (& linear velocity)
20°N, Guantanamo
30°N, Gainesville
40°N, Philadelphia
50°N, Southampton
60°N, Reykjavik70°N90°N 80°N
Change in linear velocities of various parallels of latitude (horizontal slices) increases with higher latitudes. Differences in linear velocities of the parallels cause the Coriolis effect, therefore the Coriolis effect is minimal at the Equator (small changes in linear velocities) and a maximum at the Poles (largest changes in linear velocities).
t = 0
VelocityDistance per unit time
AccelerationChange in Velocity
per unit time
Time
Dist
ance
Time
Chan
ge in
Velo
city
VelocityDistance per unit time
AccelerationChange in Velocity
per unit time
Two truckers (yellow and blue trucks) meet at rest stop at the intersection of a North-South and an East West highway. The truckers are communicating by CB.
-
+0
t = 0
t = 1
VelocityDistance per unit time
AccelerationChange in Velocity
per unit time
Time
Dist
ance
Time
Chan
ge in
Velo
city +
-0
VelocityDistance per unit time
AccelerationChange in Velocity
per unit time
FIXED FRAME OF REFERENCE(Yellow truck stationary)
The blue truck leaves the rest stop heading north up the highway while the yellow truck stays at the rest stop. The truckers continue to communicate by CB, using the strength of the signal to measure how quickly they are moving apart (velocity) and how quickly that velocity is changing (acceleration). The Coriolis effect is an acceleration.
t = 0
t = 1
2
VelocityDistance per unit time
AccelerationChange in Velocity
per unit time
Time
Dist
ance
Time
Chan
ge in
Velo
city +
-0
VelocityDistance per unit time
AccelerationChange in Velocity
per unit time
t = 0
t = 1
2
3
VelocityDistance per unit time
AccelerationChange in Velocity
per unit time
Time
Dist
ance
Time
Chan
ge in
Velo
city +
-0
VelocityDistance per unit time
AccelerationChange in Velocity
per unit time
t = 0
t = 1
2
3
4 Time
Dist
ance
Time
Chan
ge in
Velo
city +
-0
VelocityDistance per unit time
AccelerationChange in Velocity
per unit time
t = 0
t = 1
2
3
4
5
Time
Dist
ance
Time
Chan
ge in
Velo
city +
-0
VelocityDistance per unit time
AccelerationChange in Velocity
per unit time
The “acceleration” term stays fixed at zero – i.e. blue truck moving away from yellow truck of fixed position at constant velocity (40 mph).
t = 0
t = 1
2
3
4Increase inLinear velocity
AccelerationChange in Velocity
per unit time
Time
Dist
ance
Time
Chan
ge in
Velo
city +
-0
Even if the blue truck goes at twice the velocity (80 mph), forcing the distance/time graph to the left, acceleration remains at zero (neither moving apart faster or slower).
t = 0
1
1 2
Time
Dist
ance
Time
Chan
ge in
Velo
city +
VelocityDistance per unit time
AccelerationChange in Velocity
per unit time
MOVING FRAME OF REFERENCE(Yellow truck also moving)
The yellow truck heads East at the same speed (40 mph) as the blue truck is heading north. With the frame of reference (yellow truck) itself now moving the distance between the two increases more with each passing time period and so the velocity of their separation increases with time (blue up-turned function). The rate of this change (acceleration) is positive (increasing steadily). Coriolis is acceleration.
t = 0
1
2
1 2 3
Time
Dist
ance
Time
Chan
ge in
Velo
city +
VelocityDistance per unit time
AccelerationChange in Velocity
per unit time
MOVING FRAME OF REFERENCE(Yellow truck also moving)
t = 0
1
2
3
4
5
6
7
8
1 2 3 4 5 6 7 8
Time
Dist
ance
Time
Chan
ge in
Velo
city +
VelocityDistance per unit time
AccelerationChange in Velocity
per unit time
MOVING FRAME OF REFERENCE(Yellow truck also moving)
t = 0
1
2
3
4
1 2 3 4 5 6 7 8
Time
Dist
ance
Time
Chan
ge in
Velo
city +
VelocityDistance per unit time
AccelerationChange in Velocity
per unit time
MOVING FRAME OF REFERENCE(blue truck having doubled its speed)
The velocity of separation between the trucks is now greater ( steeper blue up turned function). The rate of this change (acceleration) is even more positive (increasing steadily). Acceleration increased. Coriolis effect is an acceleration.
CORIOLIS EFFECT
The higher the linear velocity of the moving object (blue truck’s velocity) relative to the moving frame of reference (the yellow truck’s position), the greater the Coriolis acceleration. Winds blowing quickly (steep pressure gradient) will be deflected to a greater extent and those blowing slowly will be deflected less (lower pressure gradient)
Coriolis Effect proportional to:-2Ω . V. Sin (φ).
where:Ω = angular velocity of earth (360°/24hrs)V = linear velocity of moving objectΦ = latitude
CORIOLIS EFFECTQuantitative Expression
top related