Contrasting Responses of Surface Heat Fluxes to Tropical Deforestation

Deforestation alters the exchange of heat, moisture, and momentum between the Earth's surface and the atmosphere, which can significantly affect the surface energy balance and water budget. However, changes in surface heat fluxes in response to deforestation are diverse among multi-model simulations. This study explores factors that might cause different changes in surface heat fluxes due to tropical deforestation with NCAR Community Land Model. The results show that the changes in surface heat fluxes are related to the mean-state flux partitioning conditions over the deforested areas. Deforestation tends to decrease both surface heat fluxes under conditions with smaller evaporative fractions (EFs), and tends to decrease the latent heat fluxes and increase the sensible heat fluxes under conditions with greater EFs. A similar relation can be found in the Land Use Model Intercomparison Project, which indicates that the varying simulated flux partitioning conditions might contribute to the diverse changes in surface heat fluxes among models.

Automated summary

Deforestation affects the exchange of heat, moisture, and momentum between the Earth's surface and the atmosphere, leading to significant impacts on surface energy balance and water budget. However, simulations from different models show diverse changes in surface heat fluxes due to deforestation. This study investigates the factors causing these variations and uses the NCAR Community Land Model to explore the impacts of tropical deforestation on surface heat fluxes. Results demonstrate that changes in surface heat fluxes are related to the initial conditions of flux partitioning over deforested areas. Deforestation tends to reduce surface heat fluxes when evaporative fractions are smaller, and decrease latent heat fluxes while increasing sensible heat fluxes when evaporative fractions are larger. Similar findings in the Land Use Model Intercomparison Project suggest that varying simulated flux partitioning conditions contribute to the diversity in surface heat flux changes among models.