Investigating the surface layer CO₂ exchange at BNF under different synoptic setups

Description

Anthropogenic climate change, that have significantly increased greenhouse gas (GHG) emissions such as carbon dioxide (CO₂) and methane (CH₄), represents a critical global challenge. These emissions are the dominant contributors to global warming, with near-surface air temperature rising by approximately 1.5°C above pre-industrial levels. CO₂ being a major GHG, it is essential to analyze its sources, sinks, and trends across various scales to better understand its role within the climate system. While changes at local, continental, and global scales are relatively well-documented, regional-scale variations remain poorly understood. Monitoring CO₂ flux is integral in identifying its sources and sinks, understanding the carbon cycle dynamics, assessing the impact of land use changes, and developing effective strategies for mitigating climate change. To date, numerous research work have been performed on the complex interplay of physical processes inCO₂ flux monitoring, including turbulent mixing, land-atmosphere interactions, and land use heterogeneity. However, the studies exploring the influence of synoptic-scale processes on the regional biospheric carbon exchange remained very limited. The south-eastern United States with its heterogeneous landscape, geographical location (Gulf of Mexico to the south, the Atlantic Ocean to the east, the Mississippi River to the west, and extending through Tennessee and North Carolina to the north), and extensive anthropogenic modification in land use provides an ideal setting for exploring the changes in CO₂ flux under diverse weather systems.

Using the high-quality, multi-instrument observation from the recently deployed 3^rd Atmospheric Radiation Measurement Mobile Facility (AMF3) in north-western Alabama’s Bankhead National Forest (BNF) we will explore the CO₂, and energy exchanges between atmosphere and biosphere under varying synoptic conditions (frontal passages, extension of Bermuda High, moist Gulf of Mexico inflow). In different stability conditions, how do the vertical profile of CO₂ flux within, at the top, and above the canopy vary under different wind and turbulence regimes will be addressed. The Eddy Covariance (EC) measurement from the 40-m tower for OCT 2024 – FEB 2025(Fall & Winter), will be used focusing on vertical structure of CO₂ fluxes in the forested environment and how it varies under different synoptic setups.