Abstract. The land surface provides a boundary condition to atmospheric forward and flux inversion models. These models require prior estimates of CO₂ fluxes at relatively high temporal resolutions (e.g., 3-hourly) because of the high frequency of atmospheric mixing and wind heterogeneity. However, land surface model CO₂ fluxes are often provided at monthly time steps, typically because the land surface modeling community focuses more on time steps associated with plant phenology (e.g., seasonal) than on sub-daily phenomena. Here, we describe a new dataset created from 15 global land surface models and 4 ensemble products in the Multi-scale Synthesis and Terrestrial Model Intercomparison Project (MsTMIP), temporally downscaled from monthly to 3-hourly output. We provide 3-hourly output for each individual model over 7 years (2004–2010), as well as an ensemble mean, a weighted ensemble mean, and the multi-model standard deviation. Output is provided in three different spatial resolutions for user preferences: 0.5°  ×  0.5°, 2.0°  ×  2.5°, and 4.0°  ×  5.0° (latitude  ×  longitude). These data are publicly available from doi:10.3334/ORNLDAAC/1315.