Interdisciplinary Seminar: Zack Taebel

The UNC-CH Department of Marine Sciences presents the interdisciplinary seminar of graduate student, Zachary Taebel. This event will be held on Monday, March 23rd, at 12:30 pm. This event will be held ONLINE ONLY and it will be available online via Zoom (Meeting ID: 291 853 980).

Seminar Title: How Langmuir Turbulence Intensifies Oceanic Carbon Uptake

Abstract: Since the industrial revolution, rising atmospheric CO2 levels and consequent global warming has been a growing threat to the health of our planet. These greenhouse gas emissions have been mitigated by oceanic carbon uptake, which has removed 41% of carbon emitted to the atmosphere since the industrial revolution. Although we have a good understanding of oceanic carbon uptake on a global scale, spatial variations at smaller scales have been more challenging to quantify. These carbon exchanges are modulated by many dynamics, particularly surface layer turbulence. When the timescales of turbulent flows and carbonate chemical reactions are of the same order of magnitude, the two can become tightly coupled. One type of turbulence that meets this criterion is wave-driven Langmuir Turbulence (LT). This talk explores a recent study comparing the effects of LT versus shear turbulence on ocean carbonate chemistry through a coupled physical and chemical model. Reaction rates were assumed time-dependent, and four trials were conducted representing different intensities of LT. The results showed that LT not only increases fluxes of CO2 into the ocean compared to shear turbulence, but also raises DIC concentrations and mixes carbon deeper into the water column. This mixing leads to a deeper and colder mixed layer, which is more conducive to gas dissolution. These effects suggest that predictions of future climates and the evolution of the carbon cycle may be incomplete without distinguishing between different types of turbulence, and the resulting spatial and temporal variations on oceanic carbon uptake.