Consistency assessment of latent heat flux and observational datasets over the Amazon basin

Abstract

The Amazon basin plays a crucial role in the global hydrological cycle and the climate system. Removal of latent heat from the surface covered by the tropical forest through evapotranspiration is a key process that still requires further research due to the complex nature of the involved processes, lack of observations and different model assumptions. Here we present an assessment of the consistency between different latent heat fluxes datasets through an indirect comparison against the daily amplitude of surface temperature and vegetation status estimated from satellite observations. Our study is based on the hypothesis that the observational satellite data can be used to provide hints on how realistically fluxes are represented in different datasets. Results evidence that datasets diverge inside the basin in both space and time, but it is possible to figure out areas under water-limited conditions, especially around the borders of the basin and some regions over eastern/southeastern Amazonia. In despite of these differences, a clear link between daily amplitude of surface temperature, leaf area index and latent heat flux can be observed over particular areas and seasons, where also correlations reach values closer to −0.98 (0.94) for surface temperature (leaf area index) indicating that satellite observations are suitable for assessing the representation of the partitioning of energy fluxes in models and widely used datasets.

Keywords

• satellite observations
• latent heat flux
• land surface temperature amplitude
• leaf area index