Shallow cumulus rooted in photosynthesis

J. Vilà-Guerau De Arellano, H.G. Ouwersloot, D. Baldocchi, C.M.J. Jacobs

Research output: Contribution to journalArticleAcademicpeer-review

21 Citations (Scopus)


We study the interactions between plant evapotranspiration, controlled by photosynthesis (C3 and C4 grasses), and moist thermals responsible for the formation of shallow cumulus clouds (SCu). Our findings are based on a series of systematic numerical experiments at fine spatial and temporal scales using large eddy simulations explicitly coupled to a plant-physiology model. The shading provided by SCu leads to strong spatial variability in photosynthesis and the surface energy balance. This in turn results in SCu characterized by less extreme and less skewed values of liquid water path. The larger water use efficiency of C4 grass leads to two opposite effects that influence boundary layer clouds: more vigorous and deeper thermals due to the larger buoyancy surface flux (positive effect) characterized by less moisture content (negative). We find that under these midlatitude and well-watered soil conditions, SCu are characterized by a larger cloud cover and liquid water path over C4 grass fields.
Original languageEnglish
Pages (from-to)1796-1802
JournalGeophysical Research Letters
Issue number5
Publication statusPublished - 2014



  • heterogeneous land surfaces
  • boundary-layer
  • soil-moisture
  • gas-exchange
  • water
  • formulation
  • vegetation
  • clouds
  • fluxes
  • co2

Cite this