two tools to measure ocean currents?

Answer 1

sea floor electrometer and global drifter buoys.

Scientists use buoys to track ocean currents and measure properties such as sea surface temperature, salinity, wind speed, and atmospheric pressure. Understanding ocean current patterns provides information that can be used to address diverse problems, such as predicting weather phenomena or tracking oil spills. Drifter data are also used by scientists at NOAA in numerical weather prediction models.

Sea floor electrometers measure the average speed of an ocean current by sensing the electric field created by salty seawater moving through the Earth's magnetic field.

Answer 2

TOOLS OF THE OCEANOGRAPHER: Measuring tools

• Current Meter -
Measures: Relative speed of water flow (current)
Operates: At any depth by cable or line
Notes: Other current meters are on top of the cupboards in lab, some have directional recorders as well

• Dye -
Measures: To stain the water so that its movement (current) can be traced
Operates: By pouring
Notes: Nontoxic and biodegradable (is gone in about 20 minutes)

• Drogues -
Measures: Currents over long distances
Operates: By releasing many and hoping for recapture (only a few percent are ever recaptured)
Notes: Like the note in a bottle, this can be a form of pollution and is not often used anymore. There are expensive buoys deployed for this purpose with the ability to send signals to satellites which can be recorded several times a day.

• Drift Bottles -
Measures: Currents
Operates: By releasing a few
Notes: May be affected by the wind but a quick and easy way to measure a current. May be considered pollution if not retrieved

• Drift Cards-
Measures: Currents
Operates: By releasing
Notes: Weighted to stay just below the surface of the water.
May be considered pollution if not retrieved

Answer 3

Acoustic Doppler Current Profiler (ADCP)
Satellites like TOPEX/POSEIDON collect data