Observation and modeling of tropical cyclones wakes and their evolution
Event: 2015 Ocean Surface Topography Science Team Meeting
Session: Science II: Mesoscale and sub-mesoscale ocean processes: current understanding and preparation for SWOT
Presentation type: Type Poster
Contribution: PDF file
Techniques using satellite altimetry can help to quantify changes in sea surface height in storm-affected regions during the months following tropical cyclones (Jansen et al., 2010; Haney et al., 2012; Mei et al., 2013; Sriver, 2013). Changes in sea surface height are closely linked to changes in ocean heat content, which enable direct estimates of the vertically integrated changes in ocean temperatures caused by tropical cyclones. However, limitations in the observational systems and in methodological approaches are likely to hamper severely significance of the results, because TC-induced SSH steric anomalies are small (~1cm) with respect to large scale SSH variations (~1m) and background variability. While SSH measurements from the current altimeter constellation shall be used for this study, it can be anticipated that the much larger coverage by the 2D SSH imaging capability of the SWOT satellite will enable more accurate estimate of these anomalies, and more direct and better tracking of the cold wake mesoscale processes. Indeed, as the surface fluxes quickly restore the pre-cyclonic SSTs (10-day timescale) and then erase the SST gradients, a 2D SSH imaging will enable to track at the monthly/seasonal timescale, for a given event, the sub-surface fronts associated with the sub-surface bolus of warm water anomaly, to better evaluate the spatial scales of the processes. Improved knowledge of the wakes restratification spatial and temporal scales is crucial to define the best methodology for heat content uptake estimation. First results will be presented to discuss the feasibility and representativeness of an approach combining all the observations available (Argo floats, satellite SSH, SSS, SST) conjointly with the understanding of processes that modeling experiments can offer.