February 13th lecture

Question 1

What is a Doldrum?

Answer 1

A region of light wind that separates trade winds in both the northern and southern hemispheres.

( basically associated with the ITCZ)

Question 2

What effect does continental shift have on the doldrums?

Answer 2

The position of the

continents shifts the doldrums into the northern hemisphere (instead of directly on the Equator)

Question 3

What direction do northern Hemi-sphere trade winds point?

Answer 3

south west towards the atmospheric intertropical convergence

Question 4

What direction do Ekamn Transports point in the Northern hemi-sphere

Answer 4

North west - making right angle with trade winds

Question 5

What direction do southern Hemi-sphere trade winds point?

Answer 5

North west -atmospheric intertropical convergence

Question 6

What direction do Ekamn Transports point in the southern hemi-sphere

Answer 6

above the equator they point to the North East towards the atmospheric intertropical convergence

below the equator they point South west away from the equator, making a right angle to the trade winds

Question 7

What is the cause of the high sea surface near doldrums?

Answer 7

there is a region of high sea surface near the the doldrums, produced by the northward Ekman transport in the region just north of the Equator

Question 8

What causes the westward South Equatorial Current (SEC) (northern hemi-sphere0

Answer 8

Flow from 5°N is directed south

by the pressure gradient and then turned to the right by the Coriolis Effect, helps strengthen SEC

Question 9

What causes the westward South Equatorial Current (SEC) (southern hemi-sphere)

Answer 9

Flow from 5°N is directed south

by the pressure gradient and then turned to the left by the Coriolis Effect, helps strengthen SEC

Question 10

Farther north, what currents are generated?

Answer 10

The North Equatorial Current (NEC)
and
the Equatorial Counter Current (ECC) are generated

Question 11

What do the strong currents to the west lead to?

Answer 11

It leads to water piling up along the western boundary

Question 12

what is created to balance the westward pilling of water?

Answer 12

The Equatorial undercurrent (EUC) is generated

Question 13

What is the Equatorial undercurrent (EUC)

Answer 13

a strong and fast current that flows directly along the Equator

Question 14

At what depth is the EUC found?

Answer 14

at 50-300m depth

Question 15

What direction does the EUC travel? Why?

Answer 15

Flows purely east-west as no
Coriolis deflection at the Equator, and should it deviate north or south the Coriolis affect pushes it back to the equator.

Question 16

How long is the EUC

Answer 16

thousands of Km’s flowing from west - east across the tropical pacific.

Question 17

What is the Indian ocean comparable to?

Answer 17

A southern hemi-sphere basin

Question 18

Why does circulation reverse seasonally?

Answer 18

because of the Monsoon?

Question 19

What is a Monsoon?

Answer 19

Monsoon is a word that means seasonal

Question 20

What drives the winds in the Indian Monsoon?

Answer 20

Heating and cooling drives winds that change between winter an summer.

Question 21

What happens during the summer of the Indian monsoon?

Answer 21

• Strong heating warms Asian land mass faster than ocean

- Creates low atmospheric pressure, rising motion precipitation, and onshore winds

Question 22

What happens during the winter of the Indian Monsoon?

Answer 22

• Air over land rapidly cools, creating higher pressure

- This drives offshore flow from land to ocean, and dry conditions over land

Question 23

What effect do changing seasonal winds have on the ocean?

Answer 23

they cause major currents to switch directions, they also change directions of Ekman transport and resulting geostrophic currents.

The Indian ocean is the only place in thw world that this happens