Fig. 5.

Top row: best-fit seasonal cycles for NH-10 zonal (left) and meridional (right) velocities at the surface and at 8 and 80 meters depth (red, blue, and black, respectively). Lower three rows: best-fit seasonal cycles of zonal (left) and meridional (right) velocities in red and daily averaged data from which the seasonal cycles are derived at each depth shown as black dots. Note the vertical scale differs in top row versus lower rows. The best-fit seasonal cycles are based on a three-harmonic fit (0, 1, 2, and 3 cycles per year) to the daily averaged time series from August 1997 – December 2021.