Quantifying Fire-Induced Surface Climate Changes in the Savanna and Rainforest Biomes of Brazil

Fernando de Sales

San Diego State University

Monday, Aug 12, 2024, 1:00 pm MT
DSRC Room GC402

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Abstract

In the first six months of 2024, the main Brazilian biomes broke records in the number of wildfires. The Cerrado (tropical savanna) has experienced the highest number of fire outbreaks ever recorded in the period since 1998, when the fires began to be monitored by satellites. In the Amazon rainforest, the number of fire outbreaks in the first half of 2024 has been the highest in the last 20 years. Long-term climate change projections indicate warmer and drier conditions in both biomes favoring longer and more intense fires. This study uses a combined-research approach based on remote-sensing and modeling to quantify the effects of burned areas on the surface climate in both aforementioned Brazilian biomes. Our estimates indicate that between 2007 and 2020, approximately 6% of the savanna and 2% of the rainforest were burned on average. Non-parametric quantile regression analyses based on model simulations indicate that latent heat flux decreases on average by approximately 0.17 W m−2 in the savanna and 0.60 W m−2 in the rainforest per each 1 km2 burned, with most of the impacts registered during the onset of the wet season. Sensible and ground heat fluxes are also impacted but at less intensity. Near-surface air is warmer and drier, especially over the rainforest burned sites. Lastly our experiments indicate that fires reduce gross primary production in the savanna and rainforest by 12% and 10%, respectively.

Fernando de Sales is an associate professor in the Department of Geology at San Diego State University.

From SDSU Bio: Fernando De Sales’ research interest lies primarily in developing a better understanding of the processes associated with Earth’s physical environment through climate models. In particular, understanding the interactions between the atmosphere and the surface has been the focus of his research. These interactions regulate heat, moisture, gas and momentum exchanges in our planet, which in turn help modulate wind patterns and precipitation regimes; and therefore are strongly linked to a sustainable human existence.

His research explores different aspects and techniques of climate modeling at regional and global, and seasonal and annual scales. He is currently involved on projects investigating the impacts of drought on groundwater, global warming effect on crops, wildfire, and the future of the Tibet Plateau snow pack. These projects are helping solve important questions, while training students to think beyond disciplinary boundaries.

He is also a faculty at the SDSU Center for Climate and Sustainability Study and an associate with the SDSU Blue Gold Center of Excellence and the Center for Information Convergence and Strategy. He is currently a member of the American Geophysical Union and the American Association of Geographers.