Exploring the sensitivity of global ocean to surface wave dependent processes — Australian Meteorological and Oceanographic Society

Exploring the sensitivity of global ocean to surface wave dependent processes (#184)

Tomoya Shimura 1 2 , Mark Hemer 2 , Andrew Lenton 2 3 4 , Matthew Chamberlain 2
  1. DPRI, Kyoto University, Uji, Kyoto, Japan
  2. CSIRO Oceans and Atmosphere, Hobart, TAS, Australia
  3. Centre for Southern Hemisphere Oceans Research, Hobart, TAS, Australia
  4. Antarctic climate & ecosystems cooperative research centre, Hobart, TAS, Australia

Current climate research has a strong dependence on climate simulations using coupled Atmosphere-Ocean Global Climate Models (AOGCMs). Realistic climate physics are required within these models to both simulate and understand climate. Key to this is fluxes of heat, mass and momentum across the air-sea interface.

Ocean surface gravity waves are driven by ocean surface winds; thus the wave climate has historically been considered to be a passive component in the atmosphere-ocean climate system. However, surface waves are part of a two-way feedback that modulate fluxes between the atmosphere and ocean. Our previous study (Shimura et al., 2017, JGR-Oceans) implemented an Atmospheric GCM coupled with a spectral wave model. Parameterisation of wave-dependent momentum roughness within that system has significant impacts on atmospheric circulation, seen in the Hadley circulation and surface wind and precipitation. This present study focuses on understanding and quantifying the impacts of wave dependent momentum roughness on ocean dynamics through implementation of a wave dependent momentum roughness into a global ocean model, MOM5 driven by atmospheric reanalysis (JRA-55). This work highlights the need to account for wave-dependent roughness modulated surface fluxes in understanding and projecting past and future changes in the climate system.

  1. T. Shimura, N. Mori, T. Takemi, R. Mizuta (2017) Long‐term impacts of ocean wave‐dependent roughness on global climate systems, JGR-Oceans, 122, pp. 1995-2011.