Statistically Measuring Wind Oscillations

#1
I have several time series of wind speed and wind direction where I am looking for some measure of oscillation with them.

Could somebody recommend somewhere I could look to do this type of analysis.

Ideally, I am looking for the following things:

1. Dominant oscillation mode for wind speed and wind direction.
2. Some measure of the significance of the oscillation mode. For example, 2 time series might both have a dominant oscillation mode of 30 degrees with a time period of 60 minutes. However one is more significant than the other.

If anybody could just point me in the right direction it would be greatly appreciated!

Thanks!

- Chris