The Good, The Bad and
The Ugly !

• Impacts Earth’s Weather Systems
• Vital to Maintaining Life on Earth!

A review of the terminology…
High/Low Latitude
Convection cell
Albedo
Coriolis Effect
Pycnocline/Density

A review of the terminology…
High/Low Latitude
Convection cell
Albedo
Coriolis Effect
Pycnocline/Density

A review of the terminology…
High/Low Latitude
Convection cell
Albedo
Coriolis Effect
Pycnocline/Density

A review of the terminology…
High/Low Latitude
Convection cell
Albedo
Coriolis Effect
Pycnocline/Density
0% 50% 100%
Albedo –the percentage of radiation reflected back to space

Extreme Albedo:
0% 50% 100%
• If Earth was covered in ice
– 84%
• If Earth was completely covered by a dark green forest canopy
– 14%
• A drop of as little as 1%
– warming influence on climate
– roughly equal to the effect of doubling the amount of CO
2 the atmosphere in

BUT —is Earth’s Albedo Changing?
YouTube - Amount of Arctic Sea Ice is Dropping Each Decade (2008.09.17)
Remember for later: An indication of warming surface waters and fresh-water input.

A review of the terminology…
High/Low Latitude
Convection cell
Albedo
Coriolis Effect
Pycnocline/Density

Earth’s Big Picture—we live on a spinning planet
• Coriolis Effect changes the intended path of all moving bodies
• Affects both atmospheric and oceanic circulation processes

The Coriolis
Effect —What is it?
• Caused by Earth’s rotation toward the east and its decrease in velocity with increasing latitude
• Motions are deflected to the right in northern hemisphere and left in southern hemisphere

A review of the terminology…
High/Low Latitude
Convection cell
Albedo
Coriolis Effect
Pycnocline/Density

T (Thermocline) + H (Halocline) = P (Pycnocline)
Low Latitudes

• Ocean Circulation
– Consists of
• Wind-driven Surface
Currents
• Density-driven Deep
Currents

Wind-driven Surface
Currents
• Atmospheric Winds
– Created from uneven solar heating
• Earth’s Albedo
• Latitude

Variations in Solar Absorption/Reflection Create
Convection Cells
• Atmospheric Low (L) occurs when warm, moist air (less dense) rises
• Atmospheric High (H) occurs when cool, dry air (more dense) sinks

Creates Earth’s
Major Surface Winds
• Tradewinds
– Low Latitudes
• Westerlies
– Mid Latitudes
• Polar Easterlies
– High Latitudes
• The Coriolis Effect gives it a ‘twist’ to the right in the northern hemisphere and a ‘twist’ to the left in the southern hemisphere

Example of Important Surface
Current Created by Winds…
• Trade Winds form the
Equatorial Currents
– Travel westward until they reach the western portion of ocean basin
(hit land)
This image shows cold water (purple) upwelling near the coast of Peru and joining the South Equatorial Current, which flows westward across the Pacific Ocean

The Power of the Ocean:
Impacts Earth’s Weather Systems
Western Intensification and
El Niño
A similar Western Intensification occurs in the Atlantic Ocean

• More in the
Pacific
• Note
Atlantic
Pattern
2009
Hurricane
Season

Jet Stream
Saturday, January 9, 2010

Surface Currents
Combine to create another remarkable system …
• Westward-moving
Equatorial Current
• ‘Hitting land’ and Coriolis
Effect results in the
Western Boundary
Currents
– e.g., the Gulf Stream and
Brazil Current in the
Atlantic ocean
Brazil Current

And then…
• Prevailing Westerlies (Mid latitude) form Eastward
Surface Currents that are, again, deflected off the continents creating the Eastern Boundary Currents

…Together They Form an Ocean Gyre
• Combination of the Equatorial, Western Boundary, Prevailing
Westerlies and Eastern Boundary Currents create a circular flow called a Gyre

AND HERE’S THE UGLY!!
Click here: Synthetic Sea - Plastic in the open Ocean

Density-driven Deep Currents
T + H = P
Low Latitude

Average Ocean Depths
Changing ocean depths influence the direction of flow.

Now —Let’s Connect the Ocean’s Surface
Currents to its Deep
Currents
…via Downwelling and Upwelling

Remember our
Pycnocline at
Low Latitudes?
T + H = P
Low Latitude

How does it look in the
Higher
Latitudes?

High Latitudes: Important Areas of Ocean Downwelling…

IMPORTANT REGION OF OCEAN UPWELLING

Remember this?

Putting it all together —
The Conveyor Belt Circulation
• A current that connects the
Ocean’s Surface
Waters to Deep waters via
Upwelling and
Downwelling
• Also called
Thermohaline
Circulation

Putting it all together —
The Conveyor Belt Circulation
• THE GOOD…
• Mixes waters within and throughout all oceans
– Oxygen flows down
– Nutrients flow up

Putting it all together —
The Conveyor Belt Circulation
• THE BAD…
• It’s demise can result in global devastation!!
The Power of the Ocean:
Vital to Maintaining Life on Earth!!

Putting it all together —
The Conveyor Belt Circulation
• Due to
– Less-dense surface waters in High
Latitudes
• Less-salty
• Warmer

Putting it all together —
The Conveyor Belt Circulation
• Due to
– Less-dense surface waters
• Less-salty
• Warmer

YouTube - GLOBAL WARNING - The Great Ocean Conveyor and
Potential Mass Extinctions

• Vast majority of land was desert interior
• Increased volcanic activity
– Increased CO
2 production
– Increased ocean acidification