Abstract :
Several recent tests with HF radars, closely packed drifters, and closely spaced ADCPs, have revealed a sub grid-scale spatial variability near the surface that disappears with depth. This impacts interpretation and measurement of instrument accuracy. For example, RMS difference of velocity between two sensors is not simply a measure of instrument error. Can such measurements of spatial turbulence be extended to temporal? What are the spatial and temporal scales? How do these vary with location, and with known physical processes? Are these measurements useful in their own right, in addition to defining better how to assess sensor accuracy?
