Biological and Environmental Research - Earth and Environmental System Sciences
Earth and Environmental System Modeling
29 October 2019

Biogeochemical Equation of State for the Sea-Air Interface

Organic surfactants distributed by the global marine food web control all modes of air-sea transfer.


We demonstrate in offline earth system model calculations that organic surfactants distributed by the global marine food web control all modes of air-sea transfer. Trace gases, momentum, heat and water vapor are all included.


Tests could be conducted in existing couple climate models given the addition of just a few lines of code. Our hypothesis is that phytoplanktonic influence will be demonstrated over vertical and horizontal mixing across the entire the ocean, through the surfactant impact on momentum transfer. Similar arguments apply to all energy modes and to climate active volatiles such as carbon dioxide, dimethyl sulfide, and water vapor. 


We have recently argued that marine interfacial surface tension must have distinctive biogeography because it is mediated by fresh surfactant macromolecules released locally through the food web. Here, we begin the process of quantification for associated climate flux implications. A low dimensionality (planar) equation of state is invoked at the global scale as our main analysis tool. For the reader’s convenience, fundamental surfactant physical chemistry principles are reviewed first, as they pertain to tangential forces that may alter oceanic eddy, ripple, and bubble fields. A model Prandtl (neutral) wind stress regime is defined for demonstration purposes. It is given the usual dependence on roughness, but then in turn on the tension reduction quantity known as surface pressure. This captures the main net influences of biology and detrital organics on global microlayer physics. Based on well-established surrogate species, tangent pressures are related to distributed ecodynamics as reflected by the current marine systems science knowledge base. Reductions to momentum and related heat-vapor exchange plus gas and salt transfer are estimated and placed on a coarse biogeographic grid. High primary production situations appear to strongly control all types of transfer, whether seasonally or regionally. Classic chemical oceanographic data on boundary state composition and behaviors are well reproduced, and there is a high degree of consistency with conventional micrometeorological wisdom. But although our initial best guesses are quite revealing, coordinated laboratory and field experiments will be required to confirm the broad hypotheses even partially. We note that if the concepts have large scale validity, they are super-Gaian. Biological control over key planetary climate-transfer modes may be accomplished through just a single rapidly renewed organic monolayer.

Scott Elliott
Los Alamos National Laboratory
Elliott, S, Z Menzo, A Jayasinghe, H Allen, O Ogunro, G Gibson, and F Hoffman.  2019.  "Biogeochemical Equation of State for the Sea-Air Interface."  Atmosphere 10(5): 230.