Fig. 6

Daily and diurnal meridional variations of the CDR echo. a Meridional variation of the CDR echo distribution at a height of 2 km during the campaign period averaged over a 100-km width (106.25° E–107.15° E) in the east–west direction from the Serpong CDR site as shown by the rectangle with dashed red lines in Fig. 1b and b its mean diurnal cycle (duplicated twice). Data in gray-shaded areas (6.83° S–6.72° S) were disregarded from the analyses because of serious ground clutter. Thin black solid horizontal lines indicate the averaged latitudinal location of the coastline (6.0° S) of the western part of Jawa Island as shown in Fig. 1b. Latitudinal locations of Pramuka (5.74° S) and Bogor (6.58° S) are also indicated by thin dashed horizontal black lines. Thick dashed lines in panel b indicate the estimated speed of DRMMs at approximately 2 m s^− 1 (5 m s^− 1) southward (northward) during the early morning (late evening) for reference. Note that, however, these DRMM dashed lines show period averaged characteristics created by superposition of diurnal cycles that varied much from day to day