第一届未来大气科学论坛

The study assesses impact of Langmuir turbulence on simulations in the North Atlantic using a climate system model. Instead
of coupling a prognostic wave model online, we utilize a statistical wave model, which is implemented into a turbulent kinetic
energy (TKE) closure scheme, to estimate Stokes drift aiming to reduce computational expenses. Another two parameterizations,
including without Langmuir turbulence and Stokes drift directly estimated by wind stress, are also compared to
explore the priority of the statistical wave model. Our findings indicate that enhanced turbulent mixing induced by Langmuir
turbulence can mitigate cold sea surface temperature and fresh sea surface salinity biases in the North Atlantic, as well as
shallow mixed-layer depth biases in the Labrador Sea. Additionally, simulation of the Atlantic Meridional Overturning Circulation
(AMOC) is improved. This improvement is attributed to enhanced turbulent mixing due to Langmuir turbulence,
which increases eddy vertical diffusivity and buoyancy loss, thereby weakening stratification in surface and thermocline
layers. Consequently, reduced stratification enhances deep convection and the generation of North Atlantic Deep Water during
boreal winter, ultimately strengthening the AMOC. Importantly, the parameterization that Stokes drift inferred from the
statistical wave model outperforms the alternative method directly inferred from wind stress, providing the most compelling
improvements in North Atlantic simulations within our fully coupled model.

Langmuir turbulence · Statistical wave model · North Atlantic · Atlantic Meridional Overturning Circulation · Climate system model