Marine Snow Carbon Pump: Understanding Organic Carbon Transport in Oceans

What Marine Snow Is

Marine snow refers to a collection of organic debris, including dead plankton, fecal pellets, and other particulate matter that sinks through the ocean water column. These particles form aggregates due to their hydrophobic nature and can vary in size from micrometers to millimeters.

These aggregates are significant because they transport carbon from surface waters to deeper layers of the ocean, contributing to long-term carbon storage.

Stokes Settling Mechanism

The settling velocity of marine snow particles is governed by Stokes' law, which describes the drag force on a spherical particle moving through a fluid. The formula for the terminal settling velocity (v) is given by v = (2/9)(ρs - ρw)d^2g/(μ), where ρs is the density of the particle, ρw is the density of water, d is the diameter of the particle, g is the acceleration due to gravity, and μ is the dynamic viscosity of water.

This settling velocity determines how quickly particles descend through the water column, influencing their fate in terms of reaching the seafloor or being remineralized by bacteria.

Martin Curve Flux Attenuation

The Martin curve is an empirical relationship that describes the rate at which organic carbon from sinking particles is remineralized as a function of depth. It is typically expressed as F = F0 exp(-bH), where F is the remineralization flux, F0 is the surface remineralization rate, H is the depth in meters, and b is an empirical coefficient known as the Martin curve exponent.

This relationship helps predict how much carbon remains in particles as they sink, impacting the efficiency of organic carbon transport to the deep ocean.

Why It Matters

Understanding marine snow and its transport mechanisms is crucial for predicting the global carbon cycle. The sequestration of carbon in deep-sea sediments can influence climate by removing CO2 from the atmosphere over long timescales.

Additionally, changes in ocean circulation or microbial activity could alter the efficiency of this process, potentially affecting future climate scenarios.

Frequently asked questions

Try it live

Everything above runs in your browser — open Marine Snow Carbon Pump (2D): Stokes Settling & the Martin Curve and change the parameters while it is running. Nothing is installed, nothing is uploaded, the whole model lives in one tab.