EAS 4300: Introduction to Oceanography, FALL 2009 

INSTRUCTORS:        Emanuele Di Lorenzo phone 404-894-3994 office ES&T 3244 email edl@eas.gatech.edu 

Kim Cobbphone 404-894-1992office ES&T 2234email kcobb@eas.gatech.edu

TA:        Andrew DavisEmail andrew.davis@eas.gatech.edu 

Course Website http://ocean3d.org/eas-4300

Why do we care about Oceanography?

How is oceanography important in understanding future climate?

What aspects of ocean sciences are relevant to the economy?

How can humans impact the ocean and climate?

Questions for you

How is oceanography important in understanding future climate?

Oceanography and Climate

Climate changes occur on different space and time scales.

TIME

SP

AC

E

Seasonal Interannual Decadal Millennial

Reg

ion

al

Basin

Wid

e

Glo

bal

Thermoregulating effects (e.g. moist air of the Gulf Stream and Kuroshio Extensions)

Oceanography and Climate - seasonal timescales

Oceanography and Climate - seasonal timescales

Sea surface temperature in the tropical oceans fuel hurricanes

Hurricanes becoming more intense as ocean warms?

Oceanography and Climate - interannual timescales

El Niño is the strongest signal of climate variability on interannual timescales. It is a coupled mechanism between the tropical ocean and atmosphere.

Thomson, R. E., and J. F. R. Gower, 1998: A basin-scale oceanic instability event in the Gulf of Alaska. J Geophys Res-Oceans, 103, 3033-3040.

Oceanography and Climate - interannual timescales

Ocean Vortices are one of the strongest mixing agent in the ocean, they are important for ocean circulation and biology. Their role in climate is still unknown!

NORTH AMERICA

Gulf of Alaska

Changes of ocean circulation affects fish distributions and abundance.

Oceanography and Climate - decadal timescales

Sardines/Anchovies

synchronized alternations between sardines/anchovies over the entire Pacific Ocean?

Changes in the ocean/atmosphere affect the ice caps, and therefore Sea Level.

Oceanography and Climate - longer timescales

Sea level will rise7 to 22” in the nextcentury, if melting does not accelerate--IPCC AR4, 2007

Marine Ecosystem regulate the cycling of chemical species relevant to climate (e.g. Carbon, DMS)

Chlorophyll Spring 2005 (MODIS Satellite)

Oceanography and Climate - longer timescales

Oceanography and Climate - millenial timescalesVertical circulation of the ocean MOVIE:

The Day After Tomorrow

e.g. The ocean has a very long memory. We will learn about this, and about the mechanisms of interaction between ocean-atmosphere-land-ecosystems.

Oceanography and Climate

Climate changes occur on different space and time scales.

What makes it interesting is that processes happening on different temporal and spatial scales are not separable and interact with each other A NONLINEAR SYSTEM COMPLEXITY

WHY?

Resources in the Ocean and Economy

What aspects of ocean sciences are relevant to the economy?

Geological Resources extraction of petroleum, gas, metals, carbonsequestration?, etc.

Ecological Resources mainly food from fisheries and maricultures

Energy Resources extraction of power from waves, tides, currents and heat content

Chemical Resources e.g. development of new drugs, salts, etc.

Recreational Resources of coastal areas, e.g. beaches and more

Oceanographic studies helped discover these resources and help to manage them (e.g. coastal processes and beaches, and many more…)

Ocean Resources, Economy and OceanographyAn example: The City of Venice, ITALY

1. Dump: rain and tides distribute it in the lagoon)

2. Factory: factories drained their liquid waste partly into the lagoon and partly into dumps. Currents and erosion continue to disperse pollutants.

3. Sea: Meteorological conditions can accentuate high tides. Bora, a cold northerly in the Adriatic Sea, and Sirocco, a hot, dust-laden wind from the Libyan desert, can trigger dangerously high tides.

4. River: the Republic of Venice diverted four rivers that originally flowed into the lagoon. The loss of the silt and sediment is transforming the delta environment into a marine one.

5. Farm: 53 percent of the phosphates and other pollutants that enter the lagoon come from these sources.

6. Town: About 1,400,000 people live in the basin, but when one considers the quantity of nutrients and organic matter generated, environmentalists say, it is as if 4,000,000 people lived there.

Offshore GAS extraction platforms

Adriatic Sea

opening to sea

Ocean Resources, Economy and OceanographyAn example: The City of Venice, ITALYusing oceanography and ocean engeneering

Adriatic Sea

More at http://www.pbs.org/wgbh/nova/venice/

opening to sea

Install Gates to control the tide

Humans impacts on the Ocean and Climate

How can humans impact the ocean and climate?

dying corals, poison fish, global warming

cholera in India, changes in Mediterranean species

city of venice was an example

Alterations: chemical (e.g. mercury, aerosols, green house gases, oil)

biological (e.g. introducing new faunas, phosphate from changes in land use, overfishing …)

physical/geological (e.g. shoreline interventions …)

CNN: Asian Brown Cloud' poses global threatAugust 12, 2002 Posted: 10:43 PM EDT (0243 GMT)

Humans impacts on the Ocean and Climate

Satellite view

Aerosols change:radiation budgetclouds concentrationamount of rain in clouds

CNN: Asian Brown Cloud' poses global threatAugust 12, 2002 Posted: 10:43 PM EDT (0243 GMT)

Humans impacts on the Ocean and Climate

Where does it come from?The sources are changing fast

Humans impacts on the Ocean and ClimateOceanography in the Indian Ocean plays a crucial role in isolating and understanding the impacts of Asian aerosols.

… aerosol pollution is only one piece of a more complex puzzle The Global Warming Issue

0.8 C

from thermometers

from paleo records

What will happenin the (near) future?An important question discussed by scientists (IPCC)

How do we define the science of Oceanography?

My personal interest

ManuOcean and climate dynamicsPhysical-biological interactions in the oceanOcean Forecasting

KimPaleoclimate and Climate ChangeIsotope GeochemistryEnergy & the Environment

We studied oceanography in San Diego at theScripps Institution of Oceanography

The Scientific Method