Ship-based observations: CTD, Nansen and Niskin bottles, inverting thermometer and Acoustic Doppler...
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Transcript of Ship-based observations: CTD, Nansen and Niskin bottles, inverting thermometer and Acoustic Doppler...
![Page 1: Ship-based observations: CTD, Nansen and Niskin bottles, inverting thermometer and Acoustic Doppler Current Profiler Ben Lee December 2, 2005 EPS 131.](https://reader031.fdocuments.in/reader031/viewer/2022032308/56649f555503460f94c795cc/html5/thumbnails/1.jpg)
Ship-based observations: CTD, Nansen and Niskin bottles, inverting thermometer and
Acoustic Doppler Current Profiler
Ben LeeDecember 2, 2005
EPS 131
![Page 2: Ship-based observations: CTD, Nansen and Niskin bottles, inverting thermometer and Acoustic Doppler Current Profiler Ben Lee December 2, 2005 EPS 131.](https://reader031.fdocuments.in/reader031/viewer/2022032308/56649f555503460f94c795cc/html5/thumbnails/2.jpg)
Topics
• Overview of ocean sampling and measurement
• CTD (Conductivity, Temperature, Depth)
• Acoustic Doppler Current Profiler
• Niskin bottles
• Nansen bottles
• Inverting or reversing thermometers
![Page 3: Ship-based observations: CTD, Nansen and Niskin bottles, inverting thermometer and Acoustic Doppler Current Profiler Ben Lee December 2, 2005 EPS 131.](https://reader031.fdocuments.in/reader031/viewer/2022032308/56649f555503460f94c795cc/html5/thumbnails/3.jpg)
Measurement and Sampling of the Ocean
![Page 4: Ship-based observations: CTD, Nansen and Niskin bottles, inverting thermometer and Acoustic Doppler Current Profiler Ben Lee December 2, 2005 EPS 131.](https://reader031.fdocuments.in/reader031/viewer/2022032308/56649f555503460f94c795cc/html5/thumbnails/4.jpg)
CTD (Conductivity, Temperature, Depth)
![Page 5: Ship-based observations: CTD, Nansen and Niskin bottles, inverting thermometer and Acoustic Doppler Current Profiler Ben Lee December 2, 2005 EPS 131.](https://reader031.fdocuments.in/reader031/viewer/2022032308/56649f555503460f94c795cc/html5/thumbnails/5.jpg)
Conductivity measurement
Temperature measurement
• Thermistor (Pt)
• Range: -1 to 40 deg C
• Accuracy: +/- 0.1deg C
• Accuracy: 0.75 psu (practical salinity unit)
• Ocean water: 35 psu = 35,000 ppm (by weight) of salt in water
![Page 6: Ship-based observations: CTD, Nansen and Niskin bottles, inverting thermometer and Acoustic Doppler Current Profiler Ben Lee December 2, 2005 EPS 131.](https://reader031.fdocuments.in/reader031/viewer/2022032308/56649f555503460f94c795cc/html5/thumbnails/6.jpg)
![Page 7: Ship-based observations: CTD, Nansen and Niskin bottles, inverting thermometer and Acoustic Doppler Current Profiler Ben Lee December 2, 2005 EPS 131.](https://reader031.fdocuments.in/reader031/viewer/2022032308/56649f555503460f94c795cc/html5/thumbnails/7.jpg)
Niskin bottles
• Bottles can be closed when desired by researchers on the ship
• Water samples can be obtained to calibrate the CTD and to investigate properties not measured by the CTD such as dissolved nutrient content, carbon dioxide, chlorofluorocarbons, and others tracers.
![Page 8: Ship-based observations: CTD, Nansen and Niskin bottles, inverting thermometer and Acoustic Doppler Current Profiler Ben Lee December 2, 2005 EPS 131.](https://reader031.fdocuments.in/reader031/viewer/2022032308/56649f555503460f94c795cc/html5/thumbnails/8.jpg)
Acoustic Doppler Current Profilers
• Can be mounted horizontally to sea walls or bridge pilings in rivers
• anchored to seafloor
• to the bottoms of ships
• lowered on a cable from ships
• Utilizes the Doppler affect to calculate particle speed in water
• Transmits “pings” and records signals that have ricocheted off particles
![Page 9: Ship-based observations: CTD, Nansen and Niskin bottles, inverting thermometer and Acoustic Doppler Current Profiler Ben Lee December 2, 2005 EPS 131.](https://reader031.fdocuments.in/reader031/viewer/2022032308/56649f555503460f94c795cc/html5/thumbnails/9.jpg)
ADCP
• In deep oceans (> 1000 m) two ADCP are lowered together one facing the surface and the other facing the bottom, to double the length of the current profile
• Petroleum jelly and chili powder repel barnacles without interrupting sound waves
• Garbage bags and electrical tape can keep the rest of the instrument clean
![Page 10: Ship-based observations: CTD, Nansen and Niskin bottles, inverting thermometer and Acoustic Doppler Current Profiler Ben Lee December 2, 2005 EPS 131.](https://reader031.fdocuments.in/reader031/viewer/2022032308/56649f555503460f94c795cc/html5/thumbnails/10.jpg)
Nansen bottles
• Approximately 12 to 24 Nansen bottles are attached in series at predetermined intervals along a cable
• Deployed with both ends open
• Closes as the bottles are reversed
• Used in conjunction with inverting or reversing thermometers
![Page 11: Ship-based observations: CTD, Nansen and Niskin bottles, inverting thermometer and Acoustic Doppler Current Profiler Ben Lee December 2, 2005 EPS 131.](https://reader031.fdocuments.in/reader031/viewer/2022032308/56649f555503460f94c795cc/html5/thumbnails/11.jpg)
Inverting thermometers
• Has a constriction in the capillary that allows it to retain its reading upon being inverted
• Deployed in pairs, one protected and the other unprotected from high pressures. Combination of the two gives temperature and pressure at the depth where reversal took place
![Page 12: Ship-based observations: CTD, Nansen and Niskin bottles, inverting thermometer and Acoustic Doppler Current Profiler Ben Lee December 2, 2005 EPS 131.](https://reader031.fdocuments.in/reader031/viewer/2022032308/56649f555503460f94c795cc/html5/thumbnails/12.jpg)
References:
• Ocean Explorer, National Oceanic and Atmospheric Administration, http://oceanexplorer.noaa.gov/welcome.html
• Introduction to Physical Oceanography, Robert H. Stewart, http://oceanworld.tamu.edu/resources/ocng_textbook/contents.html
• Oceanic In-Situ Data Access, National Oceanic and Atmospheric Administration, http://www.epic.noaa.gov/epic/ewb/ewb_help_ctd.htm
• Ocean World, http://oceanworld.tamu.edu/index.html
• Edge of the Arctic Shelf, Woods Hole Oceanographic Institution, http://www.whoi.edu/arcticedge/index.html
• Coastal Ocean Institute and Rinehart Coastal Research Center, http://www.whoi.edu/institutes/coi/facilities/instrument.htm
• Glossary of Meteorology, American Meteorological Society, http://amsglossary.allenpress.com/glossary
![Page 13: Ship-based observations: CTD, Nansen and Niskin bottles, inverting thermometer and Acoustic Doppler Current Profiler Ben Lee December 2, 2005 EPS 131.](https://reader031.fdocuments.in/reader031/viewer/2022032308/56649f555503460f94c795cc/html5/thumbnails/13.jpg)
Any Questions?