Ben Franklin published the first chart of an ocean current in 1769

Franklin’s chart of the Gulf Stream

Oceanography

Surface currents

Deep water currents

Bathymetry

Tides

Physical Oceanography

Geological Oceanography

Chemical Oceanography Dissolved Oxygen and other gases Fish and other animals

need oxygen to breathe. This oxygen is present in the water and is called dissolved oxygen (DO). It is measured in mg/L.

<3 mg/L – harmful to fish – too little O2

5-6 mg/L – desirable range

>10 mg/L – harmful to fish – too much O2

Dissolved minerals and other solids

Salinity – amount of salt in water, measured in parts per thousand (ppt)

Biological oceanography Otherwise

known as Marine Biology

MeteorologyHurricanes

Formation of Hurricanes

Photo by: Jill Turner

Hurricane Katrina 2005

Eye wall of Hurricane Ivan

2004

www.hurricanehunters.com

oceanographic tools Properties of water measured:

Parameters, units, significance• Temperature• Salinity• Dissolved oxygen • Turbidity• Light levels• Depth…

these properties vary with depth

Typical open ocean profiles Called - a hydrocast

thermocline

Temperature (°C)

Dep

th (k

m)

1

2

halocline

Salinity (‰)

Dep

th (k

m)

1

2

Density (g/ml)

Dep

th (k

m)

1

2

pycnocline

Tools to measure these properties - depth Sounding lines

Problems… (currents) Pressure sensor Sonar

Tools to measure these properties - salinity

Direct or indirect measurement Refractometer Conductivity sensor

Tools to measure these properties - turbidity

Secchi disk transmissometer

Tools to measure these properties - dissolved oxygen

Methods – chemical and electrical

Polarigraphic electrode

Winkler

Tools to measure these properties - light

Photosynthetically active radiation (PAR) sensor

Deck sensor

Water samplers

Niskin bottle

Other parameters Chlorophyll levels - fluorometer

Monitoring units Hydrolab/YSI = brands

Combined units moored, deployed, mobile CTD Argo ’floats’

CTD hydrocast

See our CTD hydrocast

The Quest for Longitude

-- 1707 shipwreck of four British warships-- 2000 dead-- Longitude Act of 1714-- John Harrison

http://www.pbs.org/wgbh/nova/longitude/

Latitude and Longitude

Global Positioning Systems

Image from Wikipedia.com

Used with permission from Garmin

Waypoint = latitude/longitude

GPS APPLICATIONS

Images from seaturtle.org

Gulf of Mexico

MEXICO