Graphical Abstract

Kadoya, T., and H. Masunaga, 2018: New observational metrics of convective self -aggregation: Methodology and a case study. J. Meteor. Soc. Japan, 96, 535-548.
https://doi.org/10.2151/jmsj.2018-054 Graphical Abstract with highlights

A new observational measure, or the morphological index for convective self-aggregation (MICA), is developed to objectively detect the signs of convective self-aggregation on the basis of a simple morphological diagnosis of convective clouds in the satellite imagery. The proposed index is applied to infrared imagery from the Meteosat-7 satellite and is assessed with the sounding-array measurements in the tropics from CINDY2011/DYNAMO field campaign data in comparison with SCAI, an existing similar index (Fig. 1).
The composite time series show that a drying proceeds over 6-12 hours as precipitation intensifies in the aggregation events. Such a drying is unclear in the non-aggregation events.
The moisture budget balance is maintained in very different manners between the two adjacent sounding arrays for the aggregation events, in contrast to the non-aggregation events which lack such apparent asymmetry. These results imply the potential utility of the proposed metrics for future studies in search of convective self-aggregation in the real atmosphere.