It is well known that El Nino-Southern Oscillation (ENSO) and the Indian Ocean Zonal Mode (IOZM) dominate the interannnual climate variability of Eastern Africa [1, 2].
We then relate the spatial patterns to known physical properties, such as ENSO and IOZM. EOF analysis is performed on annual precipitation since annual precipitation is the input in the water balance model used in this study.
They found that the first mode from the EOF analysis on regional precipitation corresponds to a combination of the first global EOF mode representing ENSO and the second global mode representing IOZM. The major warm ENSO events for the period correspond to the high peaks of the time series.