Simulation of the Onset of MJO in April 2011 using the NAVY

1. Simulation of the Onset of MJO in April 2011 using the NAVY Coupled Atmosphere-Ocean-Sea Ice Prediction System Melinda Peng1, Chaing Chen2 1Naval Research Laboratory, Monterey, CA; 2SAIC, Monterey CA INTRODUCTION NUOPC for NAVGEM-HYCOM-CICE System CICE Coupling • NAVGEM-Dummy_Ocean-CICE System • Use FNMOC Global 3D Ocean data (sst,sss,ssu,ssv) • Use FNMOC GHRSST HI-RES sst data (sst) • Use HYCOM forecast data • NAVGEM-HYCOM-CICE System • Two way coupling between NAVGEM-HYCOM • One way coupling between NAVGEM-ICE, HYCOM-CICE • Use NUOPC API to • Develop model driver and coupler components, • Facilitate model initialize, run and finalize phases, • March model components in terms of the coupling time scale, • Conduct compatibility checking for import/export fields, • Build customized connector to regrid and exchange fields among models, • Run models on separate petLists, • Build flux coupler using the Mediator. A coupled atmosphere-ocean-sea ice prediction system has been developed at Naval Research Laboratory. The backbone components of this system are the atmospheric model NAVGEM (Navy Global Environmental Model), the ocean model HYCOM (HYbrid Coordinate Ocean Model), and the sea ice model CICE (Los Alamos sea ice model). To facilitate the coupling mechanism, a NUOPC (National Unified Operational Prediction Capability) standard of the Earth System Modeling Framework (ESMF) has been implemented on top of the atmosphere, ocean, and sea ice model components. The onset of an MJO occurred on late April 2011 was observed by TRMM (Tropical Rainfall Measuring Mission). We attempted to use the coupled NOGAPS-HYCOM and NAVGEM-HYCOM systems to capture the observed onset of MJO. The preliminary result indicated that for a stand-alone NOGAPS or NAVGEM runs, the onset of MJO signature was basically absent. With the coupled systems, the onset signature was reasonably simulated when compared with the TRMM observation. We also attempted to use the coupled NAVGEM-CICE and NAVGEM-HYCOM-CICE system to explore the growing and melting of ice sheet over the Antarctic and Arctic region. We employed NAVGEM for providing the atmosphere state to drive CICE. To explore model sensitivity, we did not use HYCOM for providing the ocean state, instead we employed the analyzed sea surface temperature, salinity, and currents as the driving force for CICE. ASIS North ASIS South Coupled System Run Sequence Use Connector Use Mediator 720 Hour (30 day) Hindcasts from 1 April, 2011, ICE and SST 4391d 4912a GHRSST Analysis NAVGEM-GHRSST-CICE System 4907a 4910a ADOS2 4906a 4914a 4909a SST Cold Bias In the coupling of NOGAPS and HYCOM study, we noticed that there is a global cold bias of the sea surface temperature (SST) generated by HYCOM. To compensate the cold bias, an off-set forcing field had to be applied. The finding of the SST cold bias suggested that a further study is required to explore the role the physical parameterization in providing the energy balance in the coupled system. 720 Hour (30 day) Hindcasts from 2 April, 2011 Rainfall Hovmoller Plots (mm/day, 5S-5N) TRMM Standalone NOGAPS Without off-set (NOGAPS-HYCOM) With off-set (NOGAPS-HYCOM) With/Without off-set (NAVGEM-HYCOM) Summary • Global couple system has been developed for NAVGEM/NOGAPS, HYCOM and CICE. • Extensive long forecast runs have been conducted for NAVGEM-HYCOM/Dummy_Ocean-CICE system using NUOPC. • SST Offset appears working well for NOGAPS-HYCOM. • NAVGEM/NOGAPS-HYCOM coupled cases show eastward propagating MJO signatures over the Indian Ocean. • NAVGEM-HYCOM/Dummy_Ocean-CICE coupled cases show melting and growing of ice sheet at the Arctic and Antarctic Oceans. Coupled NAVGEM-HYCOM Coupled NOGAPS-HYCOM REFERENCE Rosmond, T., J. Teixeira, M. Peng, T. Hogan, R. Pauley, 2002: Navy Operational Global Atmospheric Prediction System (NOGAPS): Forcing for Ocean Models. Oceanography, Vol. 15, No.1. . Acknowledgement: This research is in part sponsored by ONR MM 320