Case Studies of Forest Windthrows and Mesoscale Convective Systems in Amazonia

• Published in: Geophysical research letters Vol. 50; no. 12
• Main Authors: Feng, Yanlei, Negrón‐Juárez, Robinson I., Chiang, John C. H., Chambers, Jeffrey Q.
• Format: Journal Article
• Language: English
• Published: Washington John Wiley & Sons, Inc 28.06.2023; American Geophysical Union (AGU); Wiley
• Subjects: Amazon forest; Carbon cycle; Clouds; Convection; convective storms; forest disturbance; Forests; Maximum precipitation; Mesoscale convective systems; Mesoscale phenomena; Patches (structures); Precipitation; Rainfall intensity; storms; Temperature; Thunderstorms; Weather; wind; Windthrow
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2023GL104395

This study identifies 38 cases of windthrows in the Amazonia to explore the relationship between windthrows and the characteristics (storm passing time, cloud top temperature, and maximum precipitation) of mesoscale convective systems (MCSs) that produced them. Most of windthrow cases in this study occurred in August and September. The storm passing time is positively correlated with the size of windthrows. MCSs with colder cloud top temperature (with a mean at 206 K)—indicating deeper convection—resulted in large windthrows, while those with warm cloud top (with a mean above 230 K) resulted in relatively small windthrows except for windthrows in the western Amazonia. No significant relationship is found between maximum precipitation intensity and the area of windthrows. Plain Language Summary Fan‐shaped dead forest patches were found over the entire Amazonia. These patches affect the role the Amazon forests played in the world's carbon cycle. Scientists found that frequent thunderstorms result in these dead forest patches, but how does the process happen? In this study, we explored the three characteristics of thunderstorms, including their passing over time, cloud top temperature, and associated precipitation, to identify their relationship with the size of the dead forests. We found that long‐lived thunderstorms with thicker and tall clouds, providing more power to the mesoscale convective systems, result in bigger sizes of dead forest patches. Moreover, forests in the western Amazonia are more vulnerable to thunderstorms than forests on the other parts of the Amazonia. Key Points The storm passing time of mesoscale convective systems (MCSs) is positively correlated with the size of windthrows MCSs with colder cloud top temperature are associated with larger size of windthrows No significant relationship is found between maximum precipitation intensity and the area of windthrows