// lecture 17

Question 1

Ekman Drift

Answer 1

when the wind drives the surface currents in the ocean, they drift to the right in the N. hemisphere because of the Earth’s rotation. Opposite in S. hemisphere.

Question 2

upwelling occurs near

Answer 2

coat as surface water is pushed offshore.

Question 3

meteorology and oceanography of PNW coast:

Answer 3

• during summer a high pressure system set up over the west coast gives us our fine summers.
• this high pressure system is associated with northernly surface winds along the coast.
• this drives offshore Ekman flow of the near-surface current and upwelling.
• this upwelling brings up nutrients for marine life and also hypoxic water from below.
• if the dying marine life depletes the oxygen further, then a major dead zone event can occur for slow-moving bottom dwellers.

Question 4

gulf stream warm current

Answer 4

supplies warm, salty, water to North Atlantic.

Question 5

during the end of the last ice age

Answer 5

a large amount of meltwater (zero salinity) surged into the Atlantic and shut down the thermohaline circulation for a time.

Question 6

thermohaline circulation

Answer 6

the deep flow of water downward in high latitude and upward elsewhere. thermohaline combines heat and salt, which determine the density of ocean water.

Question 7

El Niño when is the SST

Answer 7

in the eastern equatorial pacific is anomalously warm.

Question 8

La Niña when is the SST

Answer 8

in the eastern equatorial pacific is anomalously cold.

Question 9

ENSO (El Nino-Southern Oscillation)

Answer 9

the composite of the ocean and atmosphere variations that dominate tropical pacific interannual variability - time scale of 2-6 years.

Question 10

El Nino

Answer 10

phase of ENSO when the tropical SST is high in the east near South America, it rains more in the tropical east pacific and the pressure is lower in the east pacific.

Question 11

La Nina

Answer 11

phase of ENSO when the tropical SST is low in the east, it rains more in the west pacific and the pressure is lower in the west pacific.

Question 12

anomaly

Answer 12

difference from the mean long-term climatology - a departure from the expected.

Question 13

climatology

Answer 13

might be the mean for a particular season and location over many years.

Question 14

had strongest La Nina (cold eastern Pacific)

Answer 14

since 1975 (2010-2012). No big El Ninos between 1997-1998 and 2015, These are anomalies.

Question 15

winds during La Nina

Answer 15

keep warm water to the west.

Question 16

Warm SST and precipitation move to

Answer 16

central and eastern Pacific during El Nino.