SICSS
SCHOOL OF INTEGRATED
CLIMATE AND EARTH
SYSTEM SCIENCES
CLIMATE AND EARTH
SYSTEM SCIENCES
Congratulations!Gicela Vergara Successfully Defended Her Master’s Thesis
26 May 2025
Photo: Private
Gicela Vergara has successfully defended her master’s thesis titled “The Tropical Rainbelt under a 4K Warmer Sea Surface Temperature in a Global Storm-Resolving Model.” During her thesis, she joined the Climate Surface Interaction group in the Department of Climate Physics at the Max Planck Institute for Meteorology. Her work was supervised by Dr. Hans Segura, Dr. Cathy Hohenegger, and Prof. Dr. Bjorn Stevens.
The tropical rainbelt, a narrow band of precipitation centered in the tropics, significantly influences atmospheric circulation and water resource availability in tropical regions. Gicela’s work aimed to investigate how the structure of the tropical rainbelt changes under a scenario of uniform 4K increase in sea surface temperature (SST), using simulations from the global storm-resolving model ICON-Sapphire.
Her results show that under this warming scenario, tropical mean precipitation increases by approximately 3.1% per kelvin, constrained by radiative cooling. Responses of the tropical rainbelt were found not to be uniform across the tropics: over most continental areas, the rainbelt area increases, particularly during the transition months of regional monsoon systems, with the exception of Africa. In contrast, over most oceanic regions, the tropical rainbelt's area decreases.
Additionally, no substantial changes were observed in the mean latitudinal position of the tropical rainbelt across most regions.
However, notable longitudinal shifts occurred, especially over the tropical Atlantic between July and December. Here, this shift is linked to a reduction in vertical mass flux and a decrease in energy in the planetary boundary layer over the eastern Atlantic under the warming scenario.
Gicela plans to continue developing her career as a climate scientist, with a focus on understanding precipitation dynamics. Her goal is to contribute to making developing countries more resilient to extreme precipitation and related compound events.
