L4: Energy-Consistent Ocean-Atmosphere Coupling

Principal investigators: Dr. Nils Brüggemann (Universität Hamburg), Dr. Cathy Hohenegger (Max Planck Institute for Meteorology), Dr. Stephan Juricke (Jacobs University), Dr. Lars Umlauf (Leibniz Institute for Baltic Sea Research Warnemünde)

Recent studies highlight the importance of small-scale coherent structures associated with atmospheric convection and (sub-)mesoscale ocean dynamics on atmosphere-ocean feedbacks in key regions of the climate system. In state-of-the-art coupled climate models, such small-scale atmosphere-ocean feedbacks are either ignored or rely on parameterizations, which may lead to model biases and energetic inconsistencies.

Here, we propose to investigate these small-scale coupling mechanisms using coupled simulations on a global scale, based on resolutions allowing us, for the first time, to directly simulate the underlying key processes. More specifically, we will focus on the following topics:

  1. With the help of storm-resolving coupled simulations and data from a large-scale field experiment, we will investigate the interaction of shallow atmospheric convection and near-surface processes in the ocean. A special focus here will be on the dynamics of thin (meter-scale) "diurnal warm layers" and "rain layers" at the ocean surface, their role in mediating air-sea fluxes, and their feedback with atmospheric convection.
  2. We will study the effect of parameterized submesoscale dynamics like baroclinic instability and symmetric instability on air-sea exchanges in key regions of oceanic and atmospheric convection.
  3. We aim to clarify the effect of resolved mesoscale eddies on air-sea coupling, develop a new stochastic parameterization that represents such effects in surface fluxes of heat and momentum, and investigate the global and regional impact of the parameterization in coupled atmosphere-ocean simulations that cannot use high enough resolution to represent those processes explicitly.
No reports available.
  • Rackow, T., & Juricke, S (2019). Flow‐dependent stochastic coupling for climate models with high ocean‐to‐atmosphere resolution ratio. Q. J. Roy. Meteor. Soc., 1-17, https://doi.org/10.1002/qj.3674.