![]() ![]() ![]() Understanding the three-dimensional oceanic velocity response to hurricanes in the GoM is critical to accurately evaluate dynamical loading on marine oil facilities, and mixing and dispersion of suspended matter throughout the water column. These probes measured three-dimensional oceanic and atmospheric variability over the GoM mesoscale eddy field before, during, and after the passage of Isaac. Here, the effects of this upper-ocean warming response on the sea surface temperature (SST), enthalpy fluxes (latent plus sensible heat fluxes), and storm intensity are investigated using in situ data from expendable probes deployed from six NOAA research aircraft flights. Enhanced wind-driven downwelling flow caused an upper-ocean warming of ∼8 kW m −2 over these WCEs during this 12-h interval (Jaimes and Shay, 2015). This intensification stage occurred over a 12-h interval as Isaac moved over the Gulf of Mexico (GoM) mesoscale eddy field, including a warm core eddy (WCE) that had recently separated from the Loop Current (LC), a weaker anticyclone (named small WCE for simplicity hereafter) located over the steep slope of the DeSoto Canyon close to the Macondo well site, and a frontal cyclone or cold core eddy (CCE) (Fig. The aim of this study is to investigate the coupled air-sea interactions that were observed during the intensification of tropical storm (TS) Isaac (2012) into a category 1 hurricane (H1). Thus, correctly representing oceanic mesoscale eddy features in coupled numerical models is important to accurately reproduce oceanic responses to tropical cyclone forcing, as well as the contrasting thermodynamic forcing of the HBL that often causes storm intensity fluctuations over these warm oceanic regimes. Larger values in equivalent potential temperature ( θ E = 365 ∘ K) were measured inside the hurricane boundary layer (HBL) over the WCE, where the vertical shear in horizontal currents ( δ V) remained stable and the ensuing cooling vertical mixing was negligible smaller values in θ E ( 355 ∘ K) were measured over an oceanic frontal cyclone, where vertical mixing and upper-ocean cooling were more intense due to instability development in δ V. These results support the hypothesis that enhanced buoyant forcing from the ocean is an important intensification mechanism in tropical cyclones over warm oceanic mesoscale eddy features. ![]() Enhanced bulk enthalpy fluxes were estimated during this intensification stage due to an increase in moisture disequilibrium between the ocean and atmosphere. Isaac strengthened as it moved over a Loop Current warm-core eddy (WCE) where sea surface warming (positive feedback mechanism) of ∼0.5 ☌ was measured over a 12-h interval. Understanding these complex interactions is critical to correctly evaluating and predicting storm effects on marine and coastal facilities in the Gulf of Mexico, wind-driven mixing and transport of suspended matter throughout the water column, and oceanic feedbacks on storm intensity. Air-sea interactions during the intensification of tropical storm Isaac (2012) into a hurricane, over warm oceanic mesoscale eddy features, are investigated using airborne oceanographic and atmospheric profilers.
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