Transcript Cabos
Coupled Ocean-Atmosphere model for Regional Climate studies in the Mediterranean Sea William Cabos Departamento de Física Universidad de Alcalá European ROMS Workshop 6-8 November Coupling of REMO to ROMS The aim of our project Regionalization of Climate change projections of IPCC 4th AR models for the Iberian Peninsula Tool Regional coupled Ocean–Atmosphere Model Atmospheric component REMO (Regional Model) Ocean component ROMS (Regional Ocean Model System) Coupler OASIS3 coupler Each of these components has been successfully used for a wide range of climate studies. Advantages of nested climate models Regional simulations of high resolution consistent with global circulation when resources are limited avoid inconsistences between global and regional models reduce the effects of grid size changes from global to region of interest Global model Intermediate nested model Region of interest Model Setup Model domain: Atlantic Ocean, Mediterranean and Black Sea Mediterranean circulation is poorly simulated in global models Model Setup Conditions to take into account in the model It should simulate the Mediterranean present time climate and climate change projections The Atlantic ocean is necessary for the global climate signal The ocean and the atmosphere should have the same grid: no interpolation 1 hour exchange frecuency The masks should be as like as possible The Black Sea should be included COUPLED MODEL Atmosphere REMO Coupler OASIS Ocean ROMS REMO (REgional MOdel) Atmospheric General Circulation Climate Model. -developed in the Max Planck institute of Metereology -Hidrostatic - maximal grid resolution: 1/10 degree. This grid resolution enables the model to resolve the most important topographic features -Sofisticated vegetation scheme -State of the art soil, hydrographic and glaciar models -Widely used for climatic and impact studies in Europe -Echam4 physics -Rotated coordinates REMO Validation : Temperature REMO and CRU temperature: South Spain REMO and CRU temperature differences Different regions REMO Validation : Precipitation All Spain North Spain Central Spain REMO coupled model domain REMO coupled model setup OASIS Flexible, modular, well supported Sinchronization of component models Coupling fields exchange: arbitrary number, frecuency I/O actions Interpolation PSMILe communication: MPI, direct communication between models with the same grid and partition. ROMS Roms-Agrif version 0.22 degrees resolution 30 leves, qs=6.0 qb=0. Open boundaries: restoring to global coupled model data Rotated coordinates: Topography and ocean forcing fields are rotated with Eulerian angles, f calculated in geogrphical coordinates GDEM3 initial conditions Spinup with REMO 1958-2001 climatology : winds, heat and fresh water fluxes ROMS ROMS: spinup forcing REMO wind stress: February REMO wind stress: July ROMS: spinup forcing REMO Heat Flux: February REMO Heat Flux: July ROMS without nudging ROMS Black Sea with nudging (.11 degrees) ROMS .22 with nudging ROMS .22 with nudging Future work -Finish the coupling interface -Fix the bosphorous problem -Use 6-hour REMO data for spinup -Include tides -Validate ROMS -experiments with the coupled model REMO REMO Nested models A hierarchy of nested models with growing resolution allows: Regional simulations of high resolution consistent with global circulation when resources are limited To avoid inconsistences between the global model and the regional model in the region of interest To reduce the impact of grid size difference Global model Intermediate nested model Region of interest OASIS Well structured routines, allows model exchange REMO REMO REMO REMO REMO ROMS: downscaling of SODA data REMO Activities of our group related to ROMS Regional Studies: Climate change and present climate validation: Present climate: 1958 - 2001 Climate change: different scenarios:2000 - 2100 Global data: IPCC 4th AR ocean-atmosphere models Regional models: Ocean – ROMS; forced with global and regional atmosphere Atmosphere – REMO Coupling necessary for local effects REMO ROMS: downscaling of SODA data SODA Ocean reanalysis: conbines observations with ocean data from 1958 to present .5 degree resolution Does not show the most important features of Mediterranean circulation : resolution ? ROMS .12 degrees simulation with SODA boundary data Can be used for higher resolution local climate studies Weak nudging to SODA data?