Land use change exacerbates tropical South American drought by sea surface temperature variability

摘要: [1] Observations of tropical South American precipitation over the last three decades indicate an increasing rainfall trend to north and a decreasing south. Given that America has experienced significant land use change same period, it is interest assess extent which changing may have contributed trends. Simulations National Center for Atmospheric Research Community Atmosphere Model (NCAR CAM3) analyzed here suggest non-negligible impact on this behavior. While forcing model by imposed historical sea surface temperatures (SSTs) alone produces plausible north-south dipole America, NCAR CAM substantially underestimates magnitude observed southern decrease in unless associated with human-induced included. The simulated occurs primarily during local dry season regions relatively low annual-mean rainfall, as incidence very monthly-mean accumulations (<10 mm/month) increases significantly when imposed. Land also contributes temperature increase shifting turbulent flux partitioning favor sensible latent heating. Moving forward, continuing pressure from deforestation will likely occurrence drought beyond what would be expected anthropogenic warming turn compound biodiversity decline habitat loss fragmentation.