How do we know Pump locations and operating status?
The Artificial Upwelling Pump buoy is equipped with GPS, USCG-approved navigation light, triaxial accelerometer, satellite communications, solar-rechargeable battery, and controller module.
One pair of connecting lines extend to strain gauges on each connector rope between the buoy and pump outlet, measure wave period and steepness, from which we can infer wave amplitude.
The second pair of lines connect to two temperature sensors – one inside the pump outlet measuring the temperature of the upwelled water, and one outside the pump outlet measuring the ambient water temperature at ~5m.
The third pair of lines connect to two electronic paddle-wheel flow meters inside the pump outlet – one with a clutch to record just the upward flow rate (cm/s) and elapsed distance, and the other no-clutch model recording net flow rate (up and down, and elapsed distance).
The triaxial accelerometer records force and vector of the buoy riding up and down passing waves.
This AUP buoy data is uplinked periodically and provides an indication of pump operation:
- Temperature sensors will verify pumping, as the water inside the outlet registers colder compared to warmer ambient water outside the outlet.
- Sporadic or missing data from the buoy GPS suggests the buoy is riding low in the water, as waves overtopping the buoy will periodically block the GPS satellite signals. This implies excessive biofouling has offset some buoyancy.
- If the strain gauge outputs drop to low values, this suggests rope, tube or valve failure.
- Likewise the flow meter values directly measure rate of upwelled water.