Examining the processes driving changes in tropical precipitation

Rain clouds over the ocean representing tropical convection.

Conditions in the tropics impact weather and climate around the world. Understanding how clouds interact with their surrounding environment is key to improving precipitation forecasts. However, critical gaps in measurements over remote tropical oceans, especially near the surface where satellites have difficulties “seeing” in the presence of clouds, limit understanding of these processes, slow model development, and negatively impact forecasts of global weather and climate.

A new study, led by the Physical Sciences Laboratory and CIRES and recently published in the Journal of the Atmospheric Sciences, demonstrates that cloud-environment interactions cause cyclical increases and decreases in tropical precipitation, which can impact weather and climate across the globe. Because many weather and climate models have difficulty representing these “precipitation cycles”, the study examines the processes driving these changes in precipitation, and attempts to establish benchmarks/targets to guide model development. Emerging ocean-surface autonomous platform technologies also provide unique opportunities to bolster the critical gaps in current measurement capabilities.

Tropical precipitation has the ability to “teleconnect” to distant regions, impacting weather and climate across the globe. This study examines the processes driving changes in tropical precipitation, a necessary step towards improving model forecasts of weather and climate. Identifying critical gaps in current observational capabilities can help direct future investments targeted at improving weather and climate forecasts.

Wolding, Brandon (PSL/CIRES), Scott W. Powell, Fiaz Ahmed, Juliana Dias (PSL), Maria Gehne (PSL/CIRES), George N. Kiladis (PSL) and J. David Neelin (July 2022): Tropical thermodynamic-convection coupling in observations and reanalyses. J. Atmos. Sci., https://doi.org/10.1175/JAS-D-21-0256.1.