High Frequency Surface Wave Radar Studies of Inertial Oscillations

Since its inception almost 70 years ago, high frequency (HF) surface wave radar (SWR) has become ubiquitous in ocean physics research. Validation is an important aspect of this relatively new technology and presents interesting chal-lenges. In situ measurements viz.: current meters and drifters yield, respectively, instantaneous Eulerian and Lagrangian current vectors. In contrast, HFSWR vectors are inherently spatio-temporally averaged, thereby confounding direct comparison with in situ results. An additional challenge is that typical standard deviations and means of current velocities are close. We proposed an approach to validation whereby a wind driven one dimensional inertial oscillation model is fitted to the current meter observations. Model radial velocities are then compared against those of a monostatic radar. We found the radar and model velocities to be highly correlated for several days following the excitation of oscillations by a transient wind event.