Smoothed surface pressure:

The surface pressure has been despiked by first removing values that differ from the previous value by more than 5db for floats deployed since 2000, or more than 7db for floats deployed before 2000, or more than 9db for floats equipped with APF9 controller boards. The resulting time series was smoothed with a robust Lowess filter with a centre window of 5 points.

Calculated surface pressure:

A curve has been fitted to the surface pressure values.