20 Years of MCSs simulations over South America using a convection-permitting model

Author(s)

Rehbein, Amanda ; Prein, Andreas F. ; Ambrizzi, Tercio ; Ikeda, Kyoko ; Liu, Changhai ; Rasmussen, Roy M.

• Document type: Journal article
• Source: Climate Dynamics; v. 63, n. 1, p. 14-pg., 2025-01-01.

Abstract

Mesoscale convective systems (MCSs) are complex meteorological phenomena that significantly influence precipitation and weather patterns globally. While extensive research on MCSs has been conducted in various parts of the world, South America, home to some of the most intense MCSs and storms, remains a relatively understudied region. This study addresses this knowledge gap by investigating observed MCSs and their representation in a 20-year 4 km grid spacing simulation using the Weather Research and Forecasting model across different subregions of South America. MCS characteristics, such as size, duration, and maximum precipitation, are found to be well-represented by the model, although there is a tendency to overestimate maximum precipitation. Additionally, this research explores the impact of the El Ni & ntilde;o Southern Oscillation (ENSO) on MCS occurrence in South America. The Southeast South America tends to experience more MCS occurrences during El Ni & ntilde;o events, while the North-South America exhibits the opposite pattern. However, the study also reveals nuanced deviations from expected correlations during specific ENSO events, highlighting the complex relationship between ENSO and MCS behavior. These findings contribute to advancing our comprehension of mesoscale convective processes in South America and set the stage for further investigations that will focus on climate change impacts on the region. (AU)

• FAPESP's process: 14/50848-9 - INCT 2014: INCT for Climate Change
• Grantee: Jose Antonio Marengo Orsini
• Support Opportunities: Research Program on Global Climate Change - Thematic Grants
• FAPESP's process: 22/05622-9 - Atmosphere dynamics and thermodynamics associated to mesoscale convective systems over the Amazon basin using observational and cloud-resolving model simulations
• Grantee: Amanda Rehbein
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 21/07992-5 - Impact of climate change on Mesoscale Convective Systems over the Amazon basin
• Grantee: Amanda Rehbein
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 17/09659-6 - Interannual variability of the meridional transports across the SAMOC basin-wide array (SAMBAR)
• Grantee: Edmo José Dias Campos
• Support Opportunities: Research Projects - Thematic Grants