Fig. 5: Convective Initiation and vegetation.

Mean annual Normalized Difference Vegetation Index (NDVI) (a, b), locations of individual convective initiations (c, d) and total number of convective initiations gridded with a resolution of 0.11 degree (~12.3 km) (e, f) between 2004 and 2023 in Subregion I (left) and Subregion II (right). Black lines indicate the contours where the mean NDVI is 0.38, to distinguish between high and low vegetation areas. The colours in (c, d) show the distance to this contour. g, h show the number of convective initiations per distance to the NDVI contour boundary, relative to the total area with the same distance to the boundary. The lighter shades of grey in (h) include points of convective initiation over regions with topographical differences higher than 250 m over a distance of 25 km in all directions. The histograms in (g) and (h) are based on 2389 and 3952 moments of convective initiation, respectively. Negative (positive) distances indicate that the NDVI is higher (lower) than 0.38. The data include convective initiations between 10:00 and 16:30 UTC over all months of the year.