Upper ocean currents and temperature in the northeastern Pacific were measured during a 14-day period in November 1980 as part of STREX. Velocities in the upper ocean are dominated by near-inertial frequency oscillations. Thew oscillations are modified by wind stress variations associated with the passage of a strong cold front. The change in the inertial currents both in the mixed layer and below is qualitatively consistent with linear internal wave dynamics if turbulent stresses during the storm are assumed to extend 10–20 m below the mixed layer. The ratio of mean squared buoyancy frequency N2 and mean squared shear S2 computed over a 10 m interval defines an average Richardson number R0=N2/S2; R0 is approximately 2.5 except in regions of high inertial shear. In particular, values as low as 0.7 are obtained in a 20 m thick region immediately below the base of the mixed layer. The data are consistent with a model of the oecanic shear field consisting of a background shear, corresponding to a va... Abstract Upper ocean currents and temperature in the northeastern Pacific were measured during a 14-day period in November 1980 as part of STREX. Velocities in the upper ocean are dominated by near-inertial frequency oscillations. Thew oscillations are modified by wind stress variations associated with the passage of a strong cold front. The change in the inertial currents both in the mixed layer and below is qualitatively consistent with linear internal wave dynamics if turbulent stresses during the storm are assumed to extend 10–20 m below the mixed layer. The ratio of mean squared buoyancy frequency N2 and mean squared shear S2 computed over a 10 m interval defines an average Richardson number R0=N2/S2; R0 is approximately 2.5 except in regions of high inertial shear. In particular, values as low as 0.7 are obtained in a 20 m thick region immediately below the base of the mixed layer. The data are consistent with a model of the oecanic shear field consisting of a background shear, corresponding to a va...