Investigation of Precipitation Variations over Wet and Dry Areas from Observation and Model
(a) Spatial pattern of the mean GPCP V2.2 precipitation () for 1988–2012 over the tropical and subtropical regions (40°S–40°N). (b) Low-pass filtered time series of precipitation averaged over high-precipitation areas ( mm/mon.). (c) Low-pass filtered time series of precipitation averaged over low-precipitation areas ( mm/mon.). El Niño Southern Oscillation (ENSO) signals have been removed from the time series by a regression method based on the Niño3.4 index. A low-pass filter is also applied to remove the high frequency signals. Solid white contours refer to the wet area where the precipitation is higher than 200 mm/mon. Dotted white contours refer to the dry area where the precipitation is lower than 50 mm/mon.