The emerging role of the land surface in weather and climate prediction

Paul Dirmeyer
George Mason University
  29 May, Noon, in 2155


Like the ocean, the land surface is a slowly varying manifold relative to the atmosphere that provides predictability and prediction skill across a range of time scales. Although the peak influence of land surface states is in the “subseasonal” time range between 1-3 weeks, significant impact of land, or errors in its representation, begins in forecasts the first morning of simulation. The process chains that link soil moisture, vegetation, snow, and other land states through the energy and water cycles manifest though their effects on the growing daytime boundary layer, cloud formation and convection. Thus, the diurnal cycle is key to assessing and improving model performance related to land-atmosphere interactions. Daily, monthly and seasonal mean skill arising from coupled land-atmosphere feedbacks can only improve by improving the diurnal cycle.