Abstract
The atmosphere and ocean interact dynamically and thermodynamically on all scales - from microscopic to planetary scales. The physical processes through which the two systems are coupled are momentum and enthalpy fluxes across the air-sea interface. Submesoscale oceanic fronts (SFs), which typically occur on a spatial scale of 0.1-10 km and play a critical role for the downward energy transfer, may have a large influence on the atmospheric surface layer (ASL). This thesis analyzes the meteorological and oceanic measurements collected near SFs in the northern Gulf of Mexico. The first part documents the general variation of surface wind and flux across SFs. Surface wind acceleration (deceleration) in several cross-frontal transects was observed, a process previously mainly associated with mesoscale fronts. Also, a comparison between the eddy-covariance and bulk algorithm suggests that SFs locally enhance the heat flux across the air-sea interface. The second part focuses on how the atmospheric surface layer turbulence responds to SFs. The quadrant hole analysis showed that the ejection and sweep events happened more frequently in the stable condition, which leads to the difference in transport efficiencies between momentum and scalar flux. The last part focuses on the phenomena of internal wave generation associated with SFs. The high-frequency internal waves' speeds agree well with the phase speed of a simplified two-layer model. Their generations are potentially caused by the surface convergence associated subduction. Given the prevalence of SF over the global ocean, these findings suggest that these SFs may have a widely distributed and cumulative impact on air-sea interactions and energy transfer.