In News:

In a significant advancement for climate science, researchers from the Monterey Bay Aquarium Research Institute (MBARI) and Florida State University have developed a novel method to more accurately estimate oceanic carbon export using satellite data. This method, called the Lagrangian Growth-Advection Model, enhances our understanding of the ocean’s role in sequestering atmospheric carbon dioxide (CO?).

What is the Lagrangian Growth-Advection Model?

The model integrates Lagrangian tracking (which follows individual fluid parcels in motion) with advection (the horizontal movement of water) and biological growth processes. This innovative framework allows scientists to trace the journey of phytoplankton and the associated carbon flux as they move with ocean currents—particularly in dynamic regions such as the California Current upwelling system.

Key Innovations:

• Captures Spatial and Temporal Lags: Unlike conventional models, this approach accounts for delays between carbon production at the surface and its eventual export to deeper waters.
• Incorporates Biological Complexity: The model factors in zooplankton activity, biological succession, and advection of plankton communities, offering a more comprehensive representation of the carbon cycle.
• Beyond Ocean Colour: Traditional models rely heavily on ocean colour data, which is limited to surface chlorophyll concentration. The new model goes beyond this by incorporating additional ecological and physical processes.

Validation and Performance:

The model’s predictions were validated against deep-sea carbon flux measurements, particularly at Station M—a long-term ocean floor observatory operated by MBARI. Remarkably, it explained episodic pulses of carbon export previously unaccounted for by older models, marking a significant improvement in understanding carbon dynamics.

Why this Matters:

The biological pump—the process by which marine organisms convert dissolved CO? into organic carbon that eventually sinks to the deep ocean—is a crucial mechanism for long-term carbon sequestration. The ocean currently absorbs a substantial share of anthropogenic CO? emissions, helping mitigate global warming. Accurate estimates of this process are vital for climate modelling and carbon budgeting.

Existing satellite-based models fall short in capturing the subsurface processes and time-lagged carbon fluxes that significantly impact overall carbon export. The Lagrangian Growth-Advection Model addresses these limitations, offering a more realistic and dynamic understanding of the ocean’s carbon cycle.