Current$89,264
Target$85,000
Backers23
OIF (Ocean Iron Fertilization) mimics a natural CO₂ removal process by adding trace amounts of iron to the ocean surface, stimulating phytoplankton growth.
Before launching our pilot OIF project, we are conducting a small-scale experiment in California to test the measurement equipment. This involves deploying three buoys with satellite-connected sensors.
The buoys will be placed 60-70 miles offshore, floating for a short period (12-24 hours) while we monitor their position and CO₂ levels.
Thanks to your generous support, we have successfully secured the necessary funding and are now in the final stages of completion.
Progress Report
March 2025
- All the major components for the buoy systems were received and available for drift testing
- Leaks in the sensor housing were identified by pressure testing and fixed, and underwater testing was resumed
- Time constant measurements indicate improvements in the membrane for underwater CO2 measurements warrant improvement
- Getting ready for a half-day test in the San Francisco Bay and a full test in April!
February 2025
- A final configuration was designed and constructed for the sensor buoy, and initial components for flotation and a dragline are ordered
- The second and third Spotter buoys were ordered and received
- Coding was completed for collecting data for our sensors through the Spotter Iridium satellite system
- Extensive testing in air confirms that the Vaisala GMP252 sensor meets our specification for the difference between two adjacent detectors over time, while the inexpensive K30 sensor is marginal
- Underwater tests were compromised by small leaks in added sensor fittings
January 2025
- We acquired a more expensive CO2 sensor, and initial tests indicate it is likely to meet our reproducibility specification
- Additional tests on the PVC union fitting confirms that it keeps the sensor chamber dry for depths up to 1.5 m
- Tests of a prototype system for attaching sensors directly to the Spotter buoy were not encouraging, so efforts were redirected towards a separate sensor buoy connected by the Bristlemouth cable
- Sensor buoy prototype tests led to modifications for proper buoyancy and self-righting characteristics
December 2024
- Our SOFAR buoy system was picked up in San Francisco
- A capillary entry pressure of 30 psi was measured for 0.22-µm-pore PTFE filters
- PVC union fittings as housing for protecting the CO2 sensors were demonstrated to keep the sensor chamber dry for several days at depths of a meter, but membrane failures were observed at 5 meters. We decided that 0.5 meters was an adequate depth for our purposes.
- Testing of inexpensive sensors suggested they are unlikely to meet our reproducibility requirement
- The Spotter buoy was activated, and data from internal sensors is communicated to the Iridium satellite.
November 2024
- A visit to SOFAR in San Francisco led to placing an order for Spotter buoy with a Bristlemouth interface to our CO2 sensors
- Inexpensive CO2 sensor options were acquired and testing initiated
- A saltwater column was constructed to test the durability of PTFE laminated filters as a membrane to protect the sensors from water, both as splashes above the water and underwater to depths of up to 5 meters
September 2024
Kick-off meeting for the project!