Understanding the Split Characteristics of the Tropical Mesoscale Convective System (MCS) of April 9, 2018, in Northern Ghana Using Infrasound Data

Abstract

The split characteristics of the tropical Mesoscale Convective System (MCS) of April 9, 2018, in northern Ghana were studied using infrasound data measured by the mobile array (I68CI) which was deployed by Côte d’Ivoire National Data Center (NDC) in collaboration with the Comprehensive Nuclear- Test-Ban Treaty (CTBT). These infrasound measurements were made during a measurement campaign from January 1st, 2018 to December 31, 2018, in northeast Cote d’Ivoire, precisely in Comoe National Park. Graphic Progressive Multi-Channel Correlation (GPMCC) method based on a progressive study of the correlation functions was used to analyze and visualize data. The infrasound detection from this MCS shows clearly a division of the MCS structure into 2 distinct subsystems under the effect of internal and external constraints not well known but related to convection; a smaller subsystem in the north, associated with an area of intense rainfall of about 30 mm/hour and located at 9.5˚N - 2˚E with an azimuth of 70˚ and, a large subsystem in the south, associated with a zone of high rainfall of about 96 mm/hour and located at 8.8˚N - 1.4˚E with an azimuth of 90˚. These two subsystems were located 200 km and 260 km from the I68CI station with frequencies of 2.3 Hz and 1 Hz respectively. The mesoscale convective systems in this region are moving from East to West and including several storm cells.