Fig. 2: Spatial scale (in 106 sq. kilometers) of the running 15-day amount of observed rainfall from GPCP.-1DD rainfall.
From: Tropical rainfall subseasonal-to-seasonal predictability types

The spatial scales are defined as the area where the Spearman correlations are over 1/e (=0.3679) with the target grid-point. The 15-day windows when the climatological mean is below 1 mm/day are not considered. The colors are defined with the deciles of the spatial scales. The values below the map indicate the pattern correlations between the skill (Fig. 1a) and the spatial scale for the whole domain (black), the landmasses only (red) and the oceans only (blue).