Tag Archives: NOAA

Rubber Duckies and Other Oceanographic Equipment

Rubber ducks in the 2009 Ken-Ducky Derby, floating along an inland stream.  Image credit: Tony Crescibene (CC-BY)
Rubber ducks in the 2009 Ken-Ducky Derby, floating along an inland stream. Image credit: Tony Crescibene (CC-BY)

On January 10, 1992, on a voyage from Hong Kong to Tacoma, Washington, the cargo vessel Ever Laurel encountered rough seas and a container was washed off the ship. The container broke open and released its contents: 28,800 yellow rubber duckies and other floating bath toys. Since then, the duckies have been floating around, moved by wind and wave, and washed up on coasts around the world. By tracking the date and location of washed-up duckies, oceanographers can get a sense for the speed and direction of surface circulation at an oceanic scale. It’s like having 28,800 messages in bottles dumped from the same known location at the same known time.

Oceanographers sometimes want to be more precise in their measurements. The duckies probably floated very high in the water (at least at first), so that the wind could easily affect their direction and speed. Additionally, the rubber duckies are hard to track while they are at sea because they are small, few, and far between.

When more precise measurements are required, oceanographers turn to specially-designed drift buoys. These maintain a lower profile above water, and have a large “holey sock” sea anchor tethered to them in order to more accurately measure the ocean surface currents and not the wind. The buoys also have a thermometer—and sometimes additional sensors for salinity or barometric pressure—and a radio transmitter to establish the buoy’s position (by Doppler shift from 401.65 MHz, not GPS) and relay data via satellite back to the operations center.

Surface Velocity Program buoys around the world.  All instruments have sea surface temperature (SST), blue instruments have sea-level pressure (SLP).  Several red points near Heard Island and between Heard Island and Perth, Australia are from the recent R/V Investigator voyage the Heard Island area.  Image credit: NOAA (public domain).
Surface Velocity Program buoys around the world. All instruments have sea surface temperature (SST), blue instruments have sea-level pressure (SLP). Several red points near Heard Island and between Heard Island and Perth, Australia are from the recent R/V Investigator voyage the Heard Island area. Image credit: NOAA (public domain).

Different floats can be used to measure temperature and salinity profiles, rather than surface currents. Argo floats are autonomous diving instruments, which can maintain neutral buoyancy and perform controlled ascent/descent to 2000 m. These floats make their temperature, pressure, and salinity measurements during a 6–12 hour ascent. Upon reaching the surface, they transmit their GPS location and the recorded data back to the operations center via satellite. Argo floats are not cheap, with each carrying a price tag of around $15k.

On the Heard Island Expedition, our team will be deploying both of these types of instruments. These measurements will improve understanding of ocean circulation, heat content, and salinity, as well as providing ground-truth sea surface temperature measurements for use in weather forecasting models. No rubber duckies will be deployed, but we’ll document any we find washed up on the beaches.

Still want more marine science? Check out DeepSeaNews!

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Geoscientist’s Toolkit: Science on a Sphere

An educator from the Denver Museum of Nature and Science presents about sea floor spreading at the Science on a Sphere network meeting in Long Beach, CA (2012).  Image credit: Bill Mitchell.
An educator from the Denver Museum of Nature and Science presents about sea floor spreading at the Science on a Sphere network meeting hosted by the Aquarium of the Pacific in Long Beach, CA (2012). Image credit: Bill Mitchell.

One of the coolest tools I’ve had an opportunity to work with in the course of my research, outreach, and explorations of science centers, is the Science on a Sphere (SOS), which can be found at any of more than a hundred museums, educational institutions, and science centers worldwide.

Developed by NOAA, Science on a Sphere is a 1.7-meter diameter globe, surrounded by four projectors, which can display animated digital maps of the globe. Because the display is actually spherical, the maps do not have edges or strongly distorted projections, which can make looking at rectangular maps confusing.* On this display, it makes perfect sense why a flight from Los Angeles to Beijing would go near or over the Aleutian Islands of Alaska.

Many, many maps are available, covering a variety of topics including biology, geology, meteorology, planetary science, oceanography, and geography. There are maps of temperature changes going forward a hundred years, generated for each of the scenarios in the IPCC’s latest report. There are near-real-time maps of clouds seen (in infrared) by NOAA’s GOES and POES weather satellites. A near-real-time feed of earthquakes, coded by size and depth, is provided by the USGS. Following a tsunami, NOAA provides computer model output showing the wave heights as the waves travel across the ocean.

You can see the paths of commercial airplanes, the Earth at night, agricultural regions and their productivity, and the locations of volcanoes worldwide. Even the Moon, other planets (particularly Mars), and the Sun have their own visualizations.

Through the marvels of modern technology, these datasets can be overlain on top of each other, paused, backtracked, and even marked up like a sportscaster.

I spent many hours with the SOS at the Lawrence Hall of Science while I was living in Berkeley. Not only did I have fun talking with visitors about science, but I brought my favorite dataset to Science on a Sphere: near-real-time true-color imagery from the MODIS instrument aboard NASA’s Aqua satellite.

Aqua/MODIS image of Earth, March 30, 2015.  Can you spot Heard Island peeking out from the clouds?  Image credit: NASA.
Aqua/MODIS image of Earth, March 30, 2015. Can you spot Heard Island peeking out from the clouds? Image credit: NASA.

You should see if your local science center has a Science on a Sphere exhibit. The Science Museum of Minnesota does!

* For the curious, SOS maps are stored in an equirectangular (i.e. lat-long) format.