Department Seminar: Brett Buzzanga

Title: Mapping, tracking, and managing water on Earth: Insights from SWOT, GRACE, and CESM

Abstract: Human activity and internal climate variability are reshaping Earth’s water resources in profound ways, affecting the quantity and distribution of water stored on land and in the oceans.  Rising global temperatures are intensifying the hydrological cycle, resulting in more extreme shifts in water availability that lead to increased droughts in some regions and heavier rainfall and flooding in others. Simultaneously, regional sea levels continue to rise, posing an escalating threat to coastal communities worldwide.

Understanding these water movements is crucial for safeguarding future wellbeing, but characterizing them is hindered by factors such as limitations in observing systems and internal variations in the climate system that can temporarily mask or exaggerate underlying trends. Meanwhile, greenhouse gas emissions continue to rise, increasing the likelihood of severe climate impacts that may require equally extreme societal responses.

This talk is organized into three parts, each addressing a distinct aspect of the water cycle.

In the first part, I'll demonstrate how the recently launched Surface Water and Ocean Topography (SWOT) satellite, in conjunction with the new OPERA project, marks a major advance in our ability to map water from space. We'll see the transformation of Badwater Basin in Death Valley - one of the driest, hottest places on Earth - into an ephemeral lake following extreme precipitation events. Next, I'll present two decades of regional terrestrial water storage changes tracked by the GRACE/GRACE-FO missions. Using statistical analysis, we'll see where decadal variability can be isolated from trends that have persisted since 2003. Finally, we turn to the Geoengineering Large Ensemble (GLENS) experiment from the Community Earth System Model (CESM) to explore potential regional sea-level responses to a climate intervention scenario designed to stabilize global temperature. Initial analysis indicates that the intervention successfully prevents rates of sea-level change to rise above ~current day (2010-2030) levels.