On the detection of the 1 to 2 week subtropical jets over the South Pacific during November 1986-April 1987

This study analyzes the anomalous fields of the upper-tropospheric wind by removing the 30 day running means from November 1986 to April 1987.

The period has already been known as a typical El Nino year. However, a modified spectral analysis method was performed to detect the periodicity and how it changed with time. Results showed that 1 to 2 week periodic signals dominated throughout almost all that 6 month period. It is believed that this study could be useful to medium range forecasting.