Journal of the Meteorological Society of Japan. Ser. II
Online ISSN : 2186-9057
Print ISSN : 0026-1165
New Observational Metrics of Convective Self-Aggregation: Methodology and a Case Study
Toshiki KADOYAHirohiko MASUNAGA
Author information
JOURNALS FREE ACCESS Advance online publication

Article ID: 2018-054

Details
Abstract

 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 Cooperative Indian Ocean experiment on Intraseasonal variability in the Year of 2011 (CINDY2011)/Dynamics of the Madden-Julian Oscillation (MJO) (DYNAMO)/Atmospheric Radiation Measurements (ARM) MJO Investigation Experiment (AMIE). The precipitation events during the observational period are first classified by MICA into “aggregation events” and “non-aggregation events”. The large-scale thermodynamics implied from the sounding-array data are then examined with focus on the difference between the two classes. 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.

Information related to the author
© 2018 The Author(s) CC-BY 4.0 (Before 2018: Copyright © Meteorological Society of Japan)
Previous article Next article
feedback
Top