High‐Resolution Simulations of Submesoscale Processes in the Baltic Sea: The Role of Storm Events

Abstract

The traditional view of the upper ocean density stratification considers only vertical processes, such as the fluxes of momentum, heat, and freshwater that compete either to destroy or increase vertical stratification, ignoring the contribution from lateral processes (

Detecting Submesoscale Cold Filaments in a Basin‐Scale Gyre in Large, Deep Lake Geneva (Switzerland/France)

“…The simulated vertical velocity in the near-surface layer (Figures 4e and 4f) shows that downwelling velocities induced by strong surface flow convergence can reach up to 10 −3 m s −1 in the center of cold filaments. These relatively high vertical velocities are comparable to those reported by Chrysagi et al (2021). Their persistence suggests that submesoscale filaments could have an important impact on mixing/ re-stratifying the mixed layer and on primary production and surface gas exchange (Klein & Lapeyre, 2009;Mahadevan, 2016).…”

Submesoscale Processes in the Upper Red Sea

“…A good consistency is found between the distribution of F and |Ro| extrema along the frontal filaments that usually appears at the edges of mesoscale eddies (Figures 1e and 1j), suggesting that the submesoscales are actively interacting with the fronts induced by the mesoscales in the Red Sea. This is different from another marginal sea, the Baltic Sea, where a strong and persistent frontal structure is maintained by the seasonal general circulation of the basin [Chrysagi et al, 2021]. The time series of spatially averaged F corresponding to the |Ro| exhibits a correlation coefficient of 0.70 (Figure 2k), indicating that frontogenesis acts as a key element in the basin to generate the submesoscales.…”

“…The submesoscales are seasonally forced by the MLI, which is amplified via SML deepening in winter and essentially induced by the strong seasonal atmospheric forcing over the Red Sea (Yao, Hoteit, Pratt, Bower, Zhai, et al., 2014; Yao, Hoteit, Pratt, Bower, Köhl, et al., 2014; Viswanadhapalli et al., 2017; Langodan et al., 2017). Nevertheless, a recent study of the Boltic Sea suggests that the submesoscale restratification could occur rapidly (within less than a day) after strong convective events (e.g., storm), yielding localized regions with shallower SML that compensates the destratifying effect of convection (Chrysagi et al., 2021).…”

Uncertainties Associated With Simulating Regional Sea Surface Height and Tides: A Case Study of the East China Seas

“…SSH in the ECSs was simulated with the open-source General Estuarine Transport Model (GETM) 1 that has been widely applied in coastal and shelf seas (van der Molen et al, 2016;Jiang et al, 2019;Chrysagi et al, 2021). GETM solves the finite-difference approximation of Reynolds-averaged Navier-Stokes equations with the hydrostatic assumption and turbulence closure model GOTM (General Ocean Turbulence Model).…”