Week 3 : Oceans, Weather and Hazards > Topic 3a (part 1) - Ocean transport - overview

Welcome to week 3 of the course! This week we will look at how our oceans are moving and the importance of using satellite data when managing risks from ocean hazards. We can use information on currents to explain the way things move in the ocean; from plastic pollution to ice, oil spills, and algal blooms.

Ocean currents influence how efficient shipping is, and knowing where these currents are, allows the shipping industry to optimise routes for efficiency. Pollution, such as from oil spills, is also transported by ocean currents. To manage the clean up of these events, information on ocean currents can be used to predict where pollution will make landfall, or determine where it came from.

Ocean plastics are a big issue at present, and we are just learning about how extensive their presence in the oceans is. Ocean currents will influence where ocean plastics are transported and where they accumulate. This is key information when planning to clean up regions of the ocean. Ocean currents also connect ecosystems, transporting larvae of different species from one place to another. This information is important to properly conserve and manage the ocean ecosystem and the resources it supplies.

Ocean currents can be complex, and are driven by different factors including wind, gravity (in the case of tides), density, and rotation (in the case of the global thermohaline circulation and geostrophic currents).

Satellite altimeters, which measure the height of the sea surface, can be used to detect and characterise ocean currents. This data can then be used to support data assimilation into ocean models.

Optional mini task:

You can explore models of ocean currents further using this interactive map - Click on ‘ earth’ at the bottom left corner and select ‘ocean’ as the mode and ‘currents’ as the animation. You can see the different strengths and patterns of the currents. Share your observations below.

Featured Educators:

Optional further reading

View featured satellites on the satellite tracking app

To download the video above please click the ‘Download video’ button located on the top-right.

You can download the video transcript pdf below onto your computer by opening the document, right-clicking and selecting the save option.

View featured imagery, animations and external links below

3a-part-1-transcript.pdf

The normal float operation cycle.

A photograph of an Argo float - A Canadian APEX float prior to launch

The ocean currents and their speeds (in cm/s) derived from GOCE data.

Screenshot of ESA’s GlobCurrent Portal, which allows you to view global currents interactively

Global Thermohaline circulation

http://worldoceanreview.com/en/wor-1/climate-system/great-ocean-currents/

This visualization shows ocean current flows on a flat map of the world. This simple flat map (cylindrical equidistant projection) is designed to be easily wrapped to a sphere. The flows are colored by sea surface temperatures with blues being cooler waters and yellows/reds warmer waters. The time period for this visualization is 10 January 2005 through 2006. For each second the passes in the visualization, about 2.5 days pass.

Gulf Stream ccean flows colored with sea surface temperature data

Ocean surface currents around the Gulf Stream from June 2005 to December 2007 from NASA satellites.