A keynote lecture was given by one of the GHRSST meeting hosts, Jordi Isern-Fontanet (CSIC-ICM) on the role of thermal fronts and how to characterise high resolution SST. While using spectral slopes is a common tool for assessing the effective spatial resolution of SST products, which typically exhibit a drop in power following a k-2 slope, there are limitations. A common approach in turbulence-related studies is to use structure functions which also exhibit power laws, with e.g. the 2nd order structure function being the spectral slope. A characteristic of turbulent flows is the anomalous scaling, i.e. the departure from a straight line, consistent for various order functions (2nd, 4th, 6th, 8th). Thus, singularity exponents are proposed as a proxy measure for front intensity. The spatial distribution of fronts characterises the scaling of the structure functions. Anomalous scaling is proportional to the intensity of the strongest front; this is robust result that can be theoretically predicted and it implies that if front intensity changes with season, anomalous scaling will also change, thus SST products need to be coherent with this feature. In summary, ocean fronts determine the scaling properties of structure functions, with most intense fronts controlling the anomalous scaling of structure functions. This has a direct practical use in the validation of SST products

23rd International Group for High Resolution Sea Surface Temperature (GHRSST) Science Team Meeting, 27 June -1 July 2022, Barcelona

Peer reviewed