Role of dynamic and thermodynamic processes for the propagation of organized convection in a large-scale flow

Convective self-aggregation in radiative convective equilibrium has been studied due to its similarities to organized convection in the tropics. As tropical atmospheric phenomena are embedded in a large-scale flow, we impose a background wind to the model setup using convection-permitting simulation to analyze the interaction of convective self-aggregation with the background wind. The simulations show that when imposing a background wind, the convective cluster propagates in the direction of the imposed wind but slows down compared to what pure advection would suggest, and eventually becomes stationary. The dynamic process dominates slowing down the propagation speed of the cluster because the surface momentum flux acts as a drag on the near-surface wind, terminating the propagation. The thermodynamic process through the wind-induce surface feedback contributes to only 6% of the propagation speed of the convective cluster and is strongly modified by the dynamic process.

How to cite: Jung, H., Naumann, A. K., and Stevens, B.: Role of dynamic and thermodynamic processes for the propagation of organized convection in a large-scale flow, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-5075, https://doi.org/10.5194/egusphere-egu2020-5075, 2020