A new satellite-based product for studying land-atmosphere interactions

Abstract

Information about the energy and water exchanges between the land surface and the lower atmosphere (i.e. land-atmosphere interactions) is necessary for example to improve our understanding of the effect of land-atmosphere interactions on the exacerbation of temperature and precipitation extremes. Observations of energy and water fluxes at the land surface usually rely on the eddy covariance method. There is a wide network of these measurements providing data over all continents but with large spatial gaps in Africa, Asia, South America and Oceania. Additionally, other problems are associated with these observational methods such as the energy and water balance non-closure. To improve the spatial coverage of land-atmosphere interactions data considering the energy and water balance closure, we explore the combination of remote sensing data and a physical-based model. The High resOlution Land Atmosphere Parameters from Space (HOLAPS) framework is a one dimensional modelling framework that solves the energy and water balance at the land surface using remote sensing data and reanalysis products as forcings. Preliminary results from the evaluation ofHOLAPS outputs over Europe at 5 km resolution show an improvement in the simulation of latent heat flux when using remote sensing data in comparison with results using only reanalysis data as forcing. Additionally, we see a moderate improvement in HOLAPS latent heat flux estimates against energy-balance corrected eddy covariance measurements in comparison with other products that solve the energy and water balance equations, such as the ERA5Land product. The new HOLAPS product is available at hourly resolution for the period 2001 to 2016 and these estimates can be useful for agriculture and forest management activities and to evaluate the representation of land-atmosphere feedbacks in weather and climate models.