____ pressure dominates over the eastern Pacific, with ____ pressure over the western Pacific
Winds drive surface currents to the west leading to ____ in the western Pacific and _____ in eastern Pacific.
Under El Nino conditions, the pressure gradients ____ or ____, with low pressure shifting east over central Pacific.
This __/__ the westward surface winds.
As a results, warm water moves ____, shutting down the ____ of South America.
1. weaken or reverse
3. eastward; upwelling
Surface atmospheric pressure gradients are ____, ____ the trade winds, which ___ South american and Equatorial Upwelling.
intensified; increasing, increases
Strong ____ of 1972 combined with ____ contributed to the collapse of the Peruvian anchovy fishery.
El nino; over-fishing
What are the different water masses? 5
What are conservative tracers?
properties that can only be altered at the ocean boundaries or by mixing with water of different properties.
Temp. and Salinity
_____ is driven by the formation of dense water at the surface.
Dense water can be formed how?
By increasing salinity or decreasing temperature
Dense water ____, driving the ___ circulations
sinks, deep ocean
Thermohaline circulation is driven by the change in ________ and ________.
temperature and salinity
The thermocline at the middle and low latitudes is "held up" by?
the slow upward movement of cold water
Theory of Deep circulaton.
The cold water at the poles is not enough to drive the deep circulation.
The thermocline can only remain constant if there is a source of cold water from below. That is why it is said that turbulent mixing and NOT density difference drives the deep circulation. This requires overturning, hence meridional overturning circulation.
Dense water formation occurs how?
Surface cooling, freezing and evaporation
Formation of North Atlantic Deep Water. (NADW)
North Atlantic current bring warm salty surface water into Norwedian and rapid cooling occurs.
Antarctic Bottom Water formation.
Ice is formed around the Antartic continent and wind will blow ice offshore leaving behind open water. During freezing process salt is left behind and creates cold and saline water which sinks to deep water.
Formation of Mediterranean Intermediate Water (MIW):
1) Excess evaporation makes Mediterranean saltier than Atlantic Ocean.
2) This dense water spills through the Straight of Gilbraltar sinking into Atlantic
3) then mixes with Atlantic water becoming slightly less salty and reaching a stable depth.
The strength of global ocean circulation has been linked to _____?
Under El Nino conditions, the pressure gradient _____, allowing warm surface water to spread _____ across the equatorial Pacific, shutting down the South american ____.
weakened or reversed, eastward, upwelling
The deep circulation of the world's ocean is driven by _____ and ___.
Convection and turbulent mixing.
Water molecules in the crest of the wave move in the _____ direction as the wave, but molecules in the trough move in the _____ direction.
Waves are classified as? (3)
Deep-water, shallow water or Transitional
Shallow water wave : ?
Transitional water waves:
between L/2 and L/20
Waves with longer lengths and periods travel ___. Thus waves "____"
When the orbital velocity at the crest equals the wave speed, the wave ____.
The speed of the wave group is ____ the speed of the individual wave
_______ are waves which were produced elsewhere, but have traveled into an area.
Wave ____ is the propagation of a wave around an obstacle.
Types of Waves in the Ocean:
Long waves in a lake that bounces back and forth due to the wind blowing and relaxing.
____ and ____ keeps planets in orbit
gravity and inertia
Tides are huge _____waves--the ____waves in the ocean. Tides are caused by a combination of the gravitational force of the ____________.
shallow water; largest; moon and sun and the motion of Earth.
Tides on open coastlines tend to be _____________ (high tide = max velocity), but tides in embayments can be __________ (high tide = zero velocity).