Presenter: Jordan Benjamin (California Institute of Technology)

Description:
In preparation for the pilot campaign of the Sub-Mesoscale Ocean Dynamics Experiment (S-MODE), which seeks to measure submesoscale impacts in the California Current region, we examined the variability in surface horizontal currents using 2 km High-Frequency (HF) Radar Data from the CeNCOOS High-Frequency Radar array along the California Pacific Coast. We compare this data to 2km surface velocity fields from the LLC4320 simulation of the MITgcm in the same region. Structure functions are used to analyze the statistics across scales of the radar velocity field, due to their simple extensibility for unstructured data, and we additionally attempt to transform these structure functions to energy spectra in order to verify their spectral flux dynamics. Preliminary analyses show broad agreement between the datasets' energy profiles and energy transfer seasonality but suggest that there exist nontrivial discrepancies in the seasonal cycle and scale structure of energy and its transport. Due to the messy nature of the HF-RADAR data however, it is not yet clear how robust these differences are. We aim to compare our data with preliminary SMODE pilot campaign data to help resolve some of these discrepancies. Regardless, we show that the CeNCOOS HF-Radar dataset and others like it across the world provide the possibility for long time-record analysis of the seasonality in submesoscale variability, improve confidence in predictions of the seasonality in submesoscale variability driven by cycles in the mixed-layer depth, and can be used to diagnose the dynamical mechanisms of meso and submesoscale motion as they occur.