Marine Snow Sinking Lab: Understanding Carbon Flux in…

What Marine Snow Is

Marine snow refers to the natural aggregation of organic matter in the ocean, including dead plankton, fecal pellets, and other particulate detritus. These aggregates form when small particles come together due to gravity or turbulence, creating larger entities that sink through the water column.

These marine snow aggregates play a crucial role in the global carbon cycle by transporting carbon from surface waters to the deep sea, where it can be stored for long periods.

Stokes Sinking and Aggregate Fractal Density

The sinking speed of marine snow aggregates is governed by Stokes' law, which states that the terminal velocity (v) of a spherical particle in a fluid is proportional to the square of its radius (r), the density difference between the particle and the fluid ( ho_p - ho_f), and inversely proportional to the dynamic viscosity of the fluid ( u): v = (2/9)( ho_p - ho_f)r^2g/ u. The fractal dimension of these aggregates influences their shape, surface area, and thus their ability to trap more organic matter.

By adjusting the aggregate fractal density in the simulation, you can observe how changes in this parameter affect the sinking speed and efficiency of carbon transport.

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Bacterial Decay and Temperature Effects

Bacteria play a significant role in breaking down marine snow aggregates as they sink. The rate of bacterial decay is temperature-dependent, with higher temperatures generally leading to faster decomposition. This process can be modeled using the Martin curve exponent (n), which describes the relationship between the sinking velocity and the depth: v = C imes d^n.

In the simulation, you can manipulate the bacterial decay rate by adjusting the temperature or directly inputting a value for n, observing how it impacts the amount of carbon that reaches the deep sea.

Size Spectrum and Ballast Mineral Density

The size spectrum of marine snow aggregates can vary widely, from small particles to large flocculent clumps. The density of ballast minerals within these aggregates also affects their sinking speed. Heavier aggregates sink faster due to the increased gravitational force acting on them.

By altering the size spectrum and ballast mineral density in the simulation, you can explore how these factors influence the overall carbon flux through the ocean.

Frequently asked questions

How does marine snow contribute to climate change?

Marine snow aggregates transport carbon from surface waters to the deep sea, where it is stored for long periods. This process helps mitigate atmospheric CO2 levels and plays a crucial role in regulating global climate.

What are some real-world applications of studying marine snow?

Studying marine snow can help improve our understanding of the carbon cycle, predict changes in ocean ecosystems due to climate change, and inform strategies for managing marine resources.

Can human activities affect marine snow formation?

Human activities such as pollution and climate change can alter the composition and sinking rates of marine snow. For example, increased nutrient runoff can lead to more phytoplankton blooms, which in turn produce more organic matter for marine snow aggregates.

How does temperature affect bacterial decay?

Temperature affects the metabolic activity of bacteria, with higher temperatures generally increasing their rate of decomposition. This is why colder deep-sea environments tend to have slower rates of carbon turnover compared to warmer surface waters.

Try it live

Everything above runs in your browser — open Marine Snow Sinking Lab: Aggregate Fractal Density, Stokes Speed, Bacterial Decay and the Martin Curve and change the parameters while it is running. Nothing is installed, nothing is uploaded, the whole model lives in one tab.

▶ Open Marine Snow Sinking Lab: Aggregate Fractal Density, Stokes Speed, Bacterial Decay and the Martin Curve simulation

Marine Snow Sinking Lab: Understanding Carbon Flux in Oceanic Ecosystems