The FLUXCOM ensemble of global land-atmosphere energy fluxes

TLDR

Global land‑atmosphere energy fluxes, a key driver of Earth’s climate, are poorly constrained. The study uses machine learning to merge FLUXNET tower measurements with remote sensing and meteorological data to estimate global gridded net radiation, latent, and sensible heat and their uncertainties. FLUXCOM produces 147 products at 0.0833° and 0.5° resolution using MODIS and combined remote sensing plus meteorological data, applying a full factorial design of machine learning methods, forcing datasets, and energy balance closure corrections to estimate 2001–2013 global fluxes with ±1 s.d. The 2001–2013 estimates are net radiation 75.5 ± 1.4 and 77.5 ± 2.4 W m⁻², sensible heat 32.4 ± 4.2 and 35.6 ± 4.8 W m⁻², latent heat 39.1 ± 6.6 and 39.5 ± 4.5 W m⁻² (evapotranspiration 75.6 ± 9.8 and 76 ± 6.8 × 10³ km³ yr⁻¹), and the products are suitable for quantifying global land‑atmosphere interactions and benchmarking land surface models.

Abstract

Abstract Although a key driver of Earth’s climate system, global land-atmosphere energy fluxes are poorly constrained. Here we use machine learning to merge energy flux measurements from FLUXNET eddy covariance towers with remote sensing and meteorological data to estimate global gridded net radiation, latent and sensible heat and their uncertainties. The resulting FLUXCOM database comprises 147 products in two setups: (1) 0.0833° resolution using MODIS remote sensing data (RS) and (2) 0.5° resolution using remote sensing and meteorological data (RS + METEO). Within each setup we use a full factorial design across machine learning methods, forcing datasets and energy balance closure corrections. For RS and RS + METEO setups respectively, we estimate 2001–2013 global (±1 s.d.) net radiation as 75.49 ± 1.39 W m −2 and 77.52 ± 2.43 W m −2 , sensible heat as 32.39 ± 4.17 W m −2 and 35.58 ± 4.75 W m −2 , and latent heat flux as 39.14 ± 6.60 W m −2 and 39.49 ± 4.51 W m −2 (as evapotranspiration, 75.6 ± 9.8 × 10 3 km 3 yr −1 and 76 ± 6.8 × 10 3 km 3 yr −1 ). FLUXCOM products are suitable to quantify global land-atmosphere interactions and benchmark land surface model simulations.