POSTER SESSION 4
10:30–12:30, Thursday, September 17
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
ABSTRACT 1086 | POSTER 176
CHARACTERIZATION OF SETTLING AND DISSOLUTION DYNAMICS OF ALKALINE MINERALS FOR OCEAN ALKALINITY ENHANCEMENT
Achieving climate mitigation targets will require large-scale atmospheric CO2 removal. Ocean Alkalinity Enhancement (OAE) is a promising approach in which alkaline minerals increase seawater alkalinity and enhance CO2 uptake. Its effectiveness depends on the balance between particle settling and dissolution: particles must dissolve within the surface mixed layer before sinking, requiring sufficiently slow settling velocities and fast dissolution rates.
We present laboratory results quantifying the settling velocities and dissolution rates of various candidate alkaline materials. To capture these dynamics, we utilize a Real-Time Size-and-Settling-Velocity (RTSSV) instrument, enabling direct tracking of particle motion and size evolution within a vertical water column. We derive size-dependent velocity profiles, which are essential for identifying optimal material properties and deployment strategies that maximize residence time and dissolution within the mixed layer, thereby optimizing OAE efficiency.
We also detail the characterization and calibration of the RTSSV instrument, designed for field deployment with a 6,000 m depth rating. The instrument employs a dual-camera configuration with differing magnifications to image particles ranging from 3.6 to 4,200 μm and settling velocities from 10 to 17,000 μm/s. Particles are counted, sized, and tracked using custom image-processing software. We validate the instrument using particles under idealized conditions, while assessing how factors like shape, concentration, and turbidity influence detection accuracy. This calibration establishes the baseline required to translate laboratory findings into robust field observations. Ultimately, this work provides the technical foundation to assess the feasibility of mineral-based OAE as a viable climate change mitigation tool.
Sugata Paul, University of Chicago, [email protected], https://orcid.org/0009-0008-2138-752X
B.B. Cael, University of Chicago, [email protected]
Manon Duret, University of Chicago, [email protected]
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
