Changeset 1614

20/10/06 00:51:09 (15 years ago)

Updated NumSim/DIF for ECMWF ERA-40

1 edited


  • TI01-discovery/trunk/schema/numsim/NMM/higem/ECMWF-ERA-40.xml

    r1613 r1614  
    2424                <NS_Description><!-- SPACE AND TIME --> 
    2525                    The ERA-40 atmospheric analysis ws produced by three-dimensional variational data assimilation using six-hourly cycling.   
    26                     The assimilating atmospheric model had T159 spctral truncation in the horizontal, with corresponding ~125 km grid spacing,  
     26                    The assimilating atmospheric model has T159 spctral truncation in the horizontal, with corresponding ~125 km grid spacing,  
    2727                    and a 60-level resolution in the vertical, with variables represented up to a pressure of 0.1 hPa.  
    28                     The version of ECMWF's "Integrated Forecasting System" software that was operational from June 2001 to January 2002 was used.                 
     28                    ERA-40 used the version of ECMWF's "Integrated Forecasting System" software that was operational from June 2001 to January 2002.                 
    2929                </NS_Description> 
    3030                <NS_References> 
    5757                        chemistry. 
    59                         The model did not include any aerosol trend or interaction between the model's radiation schme and variable ozone fields, using instead  
     59                        The model did not include any aerosol trend or interaction between the model's radiation scheme and variable ozone fields, using instead  
    6060                        a fixed geographical distribution of aerosol and climatological ozone distribution for its radiation calculation. 
    6161                    </NS_Description> 
    6666                    <NS_ComponentType>Atmosphere</NS_ComponentType> 
    6767                    <NS_Description>  
    68                         Radiation processes are treated separately in clear and cloudy skies. 
    69                         A general 2-stream radiation code including cloud microphysics. 
    70                         The Rapid Radiation Transfer Model (RRTM) uses 6 spectral bands in the terrestrial thermal (longwave) wavelengths following   
    71                         Rodgers (1967).  
     68                        The radiative transfer equation is solved once every three hours at every fouth grid point.  
     69                        An interpolation scheme is used to obtain the shortwave and longwave radiative fluxes at every grid point and every time step.   
     71                        Longwave radiation:  
     72                        The longwave radiation scheme uses the Rapid Radiation Transfer Model (RRTM) of Mlawer et al. (1997). The RRTM uses 
     73                        a correlated-k method with absorption coefficients for the relevant k-distributions derived from the  
     74                        Line By Line Radiative Transfer Model (LBLRTM) of Clough et al. (1989, 1992), Clough and Iacono (1995). 
     75                        Compared to the original RRTM (Mlawer et al., 1997), the version used at ECMWF has been slightly modified to account for  
     76                        cloud optical properties and surface emissivity defined for each of the 16 bands over which spectral fluxes are computed.  
     77                        The ECMWF model has no provision for scattering in the longwave. 
     79                        Shortwave radiation: 
    7280                        The solar (shortwave) radiation scheme uses a photon path distribution method to account for the simultaneous occurance of  
    7381                        scattering and molecular absorption when the exact amount of absorber along the photon path length is unkown. 
    7483                        The radiative effects of clouds, aerosols, carbon dioxide, ozone and trace gases are included in the radiation scheme.  
    75                         Cloud fraction, and liquid/ice water content is provided in all layers by the cloud scheme. 
     84                        Cloud fraction, and liquid/ice water content is provided in all layers by the cloud scheme. Radiation processes are treated  
     85                        separately in clear and cloudy skies. 
    7686                        Horizontal distributions for four climatological types of aerosols (oceanic, desert, urban, and stratospheric background) are  
    7787                        defined from T5 spectral coefficients, with fixed vertical distributions following Tanre et al. (1984). 
    7989                        0.31 ppm, 280 ppt, and 484 ppt respectively (IPCC/SACC, 1990). 
    8090                        Ground albedo, emissivity and solar zenith angle are also incorporated into the radiaton scheme. 
    81                     </NS_Description> 
    82                     <NS_References> 
     92                    </NS_Description> 
     93                    <NS_References> 
     94                        <NS_Reference> 
     96                        </NS_Reference> 
     97                        <NS_Reference> 
     98                            Clough, S.A., F.X. Kneizys, and R.W. Davies, 1989: Line shape and the water vapor continuum.  
     99                            Atmos. Res., 23, 229-241. 
     100                        </NS_Reference> 
     101                        <NS_Reference> 
     102                            Clough, S.A., M.J. Iacono, and J.-L. Moncet, 1992: Line-by-line calculations of atmospheric fluxes and cooling rates:  
     103                            Application to water vapor. J. Geophys. Res., 97D, 15761-15786. 
     104                        </NS_Reference> 
     105                        <NS_Reference> 
     106                            Clough, S. A. and M. I. Iacono, 1995: Line-by-line calculation of atmospheric fluxes and cooling rates, 2.  
     107                            Application to carbon dioxide, ozone, methane, nitrous oxide and the halocarbons.  
     108                            J. Geophys. Res., 100D, 16519-16536. 
     109                        </NS_Reference> 
     110                        <NS_Reference> 
     111                            Mlawer, E.J., S.J. Taubman, P.D. Brown, M.J. Iacono, and S.A. CLough, 1997: Radiative transfer for inhomogeneous atmospheres:  
     112                            RRTM, a validated correlated-k model for the longwave. J. Geophys. Res., 102D, 16663-16682. 
     113                        </NS_Reference> 
    83114                        <NS_Reference> 
    84115                            Tanre, D., Geleyn, J.-F. and Slingo, J. M., 1984: `First results of the introduction of an advanced aerosol-radiation interaction  
    85116                            in the ECMWF low resolution global model'. In  Aerosols and Their Climatic Effects. H.E. Gerber and A. Deepak, Eds., A. Deepak  
    86117                            Publ., Hampton, Va., 133-177. 
    87                         </NS_Reference> 
    88                         <NS_Reference> 
    89                             Rodgers, C. D., 1967: `The radiative heat budget of the troposphere and lower stratosphere'.  
    90                             Report A2, Planetary Circulation Project, Dept. of Meteorology, M.I.T., Cambridge, Mass., 99 pp. 
    91118                        </NS_Reference> 
    92119                    </NS_References> 
    200227                        </NS_Reference> 
    201228                        <NS_Reference> 
     229                            Baines, P. G. and Palmer, T. N., 1990: `Rationale for a new physically based parametrization of subgrid-scale orographic effects'.  
     230                            Technical Memorandum 1699. European Centre for Medium-Range Weather Forecasts.                             
     231                        </NS_Reference> 
     232                        <NS_Reference> 
    202233                            Lott, F. and Miller, M. J., 1996: A new subgrid-scale orographic drag parametrization: Its formulation and testing,  
    203234                            Q. J. R. Meteorol. Soc., 123, 101-127. 
    204                         </NS_Reference> 
    205                         <NS_Reference> 
    206                             Baines, P. G. and Palmer, T. N., 1990: `Rationale for a new physically based parametrization of subgrid-scale orographic effects'.  
    207                             Technical Memorandum 1699. European Centre for Medium-Range Weather Forecasts.                             
    208235                        </NS_Reference> 
    209236                        <NS_Reference> 
    294321                    </NS_References> 
    295322                </NS_Component> 
    296                 <NS_Component><!-- Aerosols --> 
    297                     <NS_Name>Aerosols</NS_Name> 
    298                     <NS_ComponentType>Atmosphere</NS_ComponentType> 
    299                     <NS_Description> 
    300                         The aerosol parameterisation includes a sulphur cycle, soot scheme and biomass aerosol scheme. 
    301                         The sulphur cycle includes SO2 emissions from the surface, chimneys and volcanoes. 
    302                         The sulphur cycle also uses an interactive dimethyl sulphide scheme. 
    303                         The biomass scheme includes emissions from the surface and from high levels. 
    304                     </NS_Description> 
    305                 </NS_Component> 
    306                 <NS_Component><!-- Rivers --> 
    307                     <NS_Name>Rivers</NS_Name> 
    308                     <NS_ComponentType>LandSurface</NS_ComponentType> 
    309                     <NS_Description> 
    310                         All rivers flow with an effective velocity of 0.4 m/s and a meander ratio of 1.4. 
    311                         River outflow to the ocean is included. 
    312                     </NS_Description> 
    313                 </NS_Component> 
    314323            </NS_Component>             
    315             <NS_Component><!-- OCEAN --> 
    316                 <NS_Name>Ocean</NS_Name> 
    317                 <NS_ComponentType>Ocean</NS_ComponentType> 
    318                 <NS_Description><!-- SPACE AND TIME --> 
    319                     The oceanic component of HiGEM has 40 vertical levels with  
    320                     a horizontal resolution of 0.333 degrees of latitude by 0.333 degrees of longitude,  
    321                     which produces a global grid of 1082 x 540 grid cells. This is equivalent to a surface 
    322                     resolution of about 37 km x 37 km at the Equator, reducing to 26 km x 37 km 
    323                     at 45 degrees of latitude (comparable to a spectral resolution of Nblah). 
    324                     The atmospheric timestep period is 20 minutes (72 timesteps per 1 days).    
    325                     The ocean GCM includes a polar island as standard. 
    326                     The ocean GCM uses the McDougall equation of state. 
    327                 </NS_Description> 
    328                 <NS_References> 
    329                     <NS_Reference></NS_Reference> 
    330                 </NS_References> 
    331                 <NS_Component><!-- tracer advection and diffusion--> 
    332                     <NS_Name>Tracer advection and diffusion</NS_Name> 
    333                     <NS_ComponentType>Ocean</NS_ComponentType> 
    334                     <NS_Description> 
    335                         The advection of active tracers, temperature and salinity, uses a fourth order differencing scheme (Pacanowski and Griffies, 1998) 
    336                         which uses a fourth order estimate of the tracer gradients together with the second order advective fluxes.                       
    337                         The option to use upwind advection in the bottom gridcell at each point avoids instabilities found in high resolution runs. 
    338                         The Griffies diffusion scheme orientates the mixing tensor to lie along isopycnal rather than horizontal sufarces (Griffies et al., 1998). 
    339                         Isopycnal diffusivity is 5.00e+02 (m*m/s) and is constant with depth. 
    340                         The Gent and McWilliams (GM) Scheme parametrises the effect of mesoscale eddies on tracer transports. 
    341                         The Visbeck scheme allows the diffusivity for the GM scheme to be spatially and temporally variable,  
    342                         so that it can take large values in eddy-generation regions and small values elsewhere.  
    343                         The HADCM4 version of the Visbeck scheme uses large-scale density gradients to pick out eddy-generation regions. 
    344                         The isopycnal diffusivity is tapered as the slope of the isopycnals increases using a hyperbolic tangent function. 
    345                         A scale-selective version of the Gent and McWilliams scheme (Roberts and Marshall 1998) removes small-scale noise from the tracer fields 
    346                         without affecting their large-scale distribution and without causing any mixing across isopycnal surfaces. 
    347                     </NS_Description> 
    348                     <NS_References> 
    349                         <NS_Reference>Pacanowski and Griffies, MOM 3.0 Manual, 1998</NS_Reference> 
    350                         <NS_Reference></NS_Reference> 
    351                         <NS_Reference>Griffies et al 1998</NS_Reference> 
    352                         <NS_Reference>Roberts and Marshall, 1998</NS_Reference> 
    353                     </NS_References> 
    354                 </NS_Component>                 
    355                 <NS_Component><!-- Fourier filtering at high latitudes --> 
    356                     <NS_Name>Filtering</NS_Name> 
    357                     <NS_ComponentType>Ocean</NS_ComponentType> 
    358                     <NS_Description> 
    359                         Fourier filtering is used to decrease the effective resolution of the model at 
    360                         high latitudes, allowing a longer timestep to be used. See UMDP 40. Different 
    361                         filtered regions can be chosen for tracers and velocity and for the northern 
    362                         and southern hemispheres. In the northern hemisphere, filtering starts at 
    363                         'First tracer/velocity row in northern hemisphere to be filtered' and goes 
    364                         right up to the north pole. The filtering removes scales less than the grid 
    365                         scale on the row defined by 'Tracer/velocity row used to define basic zonal 
    366                         dimension'. The equator-most row to be filtered in each hemisphere determines 
    367                         the minimum effective gridlength retained by the filtering. 
    368                         The first tracer/velocity row in the northern hemisphere: 510/509 
    369                         Tracer/velocity row used to define basic zonal dimensions: 510/509 
    370                         The last tracer/velocity row in the southern hemisphere:34/34 
    371                     </NS_Description> 
    372                     <NS_References> 
    373                         <NS_Reference></NS_Reference> 
    374                     </NS_References> 
    375                 </NS_Component> 
    376                 <NS_Component><!-- Mixed layer and vertical diffusion--> 
    377                     <NS_Name>Mixed Layer and vertical diffusion</NS_Name> 
    378                     <NS_ComponentType>Ocean</NS_ComponentType> 
    379                     <NS_Description> 
    380                         A Kraus-Turner (1967) type mixed layer model is used to parameterise the effects of surface generated turbulence.  
    381                         Vertical diffusion is dependent on the Ricardson Number (Peters et al, ?) 
    382                         The quadratic Large scheme calculates the vertical diffusion coefficient in the mixed layer (Large et al 1994) 
    383                         The quadratic Large scheme is applied where the Richardson number is less than 0.3 upto a maximum depth of 80 m. 
    384                     </NS_Description> 
    385                     <NS_References> 
    386                         <NS_Reference>Kraus Turner, 1967</NS_Reference> 
    387                         <NS_Reference></NS_Reference> 
    388                         <NS_Reference>Peters et al, ?</NS_Reference> 
    389                         <NS_Reference>W.G.Large et al 1994, Oceanic Vertical Mixing : A review and a model 
    390                         with a nonlocal boundary layer parametrisation, Rev Geophys, 32, 363-403.</NS_Reference> 
    391                     </NS_References> 
    392                 </NS_Component> 
    393                 <NS_Component><!-- Barotropic Solution, Momentum Flux and Diffusion --> 
    394                     <NS_Name>Barotropic Solution, Momentum Flux and Diffusion</NS_Name> 
    395                     <NS_ComponentType>Ocean</NS_ComponentType> 
    396                     <NS_Description>   
    397                         A free-surface barotropic solution is used with Delphus-Delcross smoothing for the surface height field. 
    398                         A modifed Cox scheme is used for calculating velocity fluxes. 
    399                         Horizontal momentum diffusion uses viscosity coeffiecients that are constant in latitude: 0.00. 
    400                         Biharmonic momentum diffusion allows scale-selective damping to be applied to the velocities 
    401                         without affecting the large-scale velocity field. It is useful in helping the removal of grid-scale noise in the velocity field.  
    402                     </NS_Description> 
    403                 </NS_Component> 
    404                 <NS_Component><!-- Convection --> 
    405                     <NS_Name>Convection</NS_Name> 
    406                     <NS_ComponentType>Ocean</NS_ComponentType> 
    407                     <NS_Description> 
    408                         A Rahmstorf's full convection scheme is used which 
    409                         is guaranteed to produce a profile having complete static stability. 
    410                     </NS_Description> 
    411                 </NS_Component> 
    412                 <NS_Component><!-- Salinity Control --> 
    413                     <NS_Name>Salinity Control</NS_Name> 
    414                     <NS_Description> 
    415                         There is no reference salinity, instead salinity limits are applied. 
    416                         Upper salinity limit: 4.50000e-02 (psu/1000). 
    417                         Lower salinity limit: 5.00000e-03 (psu/1000). 
    418                     </NS_Description> 
    419                 </NS_Component> 
    420                 <NS_Component><!-- Ocean straits --> 
    421                     <NS_Name>Ocean Straits</NS_Name> 
    422                     <NS_ComponentType>Ocean</NS_ComponentType> 
    423                     <NS_Description> 
    424                         A generalised strait exchange scheme is used that advects water from a marginal sea into the main                                    
    425                         ocean, with a corresponding return flow. 
    426                         There is 1 strait in this set up with end coordinates (i,j) at (62, 378) and (65, 378). 
    427                     </NS_Description> 
    428                 </NS_Component>                 
    429             </NS_Component>           
    430             <NS_Component><!-- SEA ICE (part of ocean scheme really)--> 
    431                 <NS_Name>Sea Ice</NS_Name> 
    432                 <NS_ComponentType>Cryosphere</NS_ComponentType> 
    433                 <NS_Description><!-- Sea Ice --> 
    434                     The prognostic sea ice model contains ice thermodynamics based on  
    435                     Semtner's "zero-layer" and calculates prognostic ice depth, ice concentration and snow depth.    
    436                     The multiple ice categories model allows the sub-grid scale ice thickness distribution to be represented.  
    437                     The EVP (elastic-viscous-plastic) dynamics based on Hibler's sea-ice rheology calculates velocities  
    438                     that are used to advect sea-ice. 
    439                     A north polar island is included and sea ice can be advected over it. 
    440                 </NS_Description> 
    441                 <NS_References> 
    442                     <NS_Reference> 
    443                         Semtner, A. J., 1976:  
    444                         A model for the thermodynamic growth of sea ice in numerical investigations of climate.  
    445                         J. Phys. Oceanogr., 6, 379-389.  
    446                     </NS_Reference> 
    447                     <NS_Reference> 
    448                         Hibler, W. D., 1979: Dynamic Thermodynamic Sea Ice Model. 
    449                         Journal of Physical Oceanography, 9(4), 815-846. 
    450                     </NS_Reference> 
    451                 </NS_References> 
    452                 <NS_Component><!-- Sea Ice Thermodynamics --> 
    453                     <NS_Name>Sea Ice Thermodynamics</NS_Name> 
    454                     <NS_ComponentType>Cryosphere</NS_ComponentType> 
    455                     <NS_Description> 
    456                         Ocean to ice heat flux parameterisation uses the 'McPhee scheme'  
    457                         (McPhee, 1992), which uses both the ocean-ice temperature difference and 
    458                         the friction velocity in the flux parameterisation.   
    459                         The 'McPhee scheme'  produces a flux proportional to the ice concentration 
    460                         above a marginal sea ice concentration of 0.05.  For lower concentrations, 
    461                         the heat flux is constant. 
    463                         Number of sea ice categories is 5.                        
    464                         Minimum local ice depth is 0.1 m.  
    465                         Min local snow thickness: 1.0E-5 m                        
    466                         Min local thickness of new ice growing in leads: 0.05m 
    467                     </NS_Description> 
    468                     <NS_References> 
    469                         <NS_Reference> 
    470                             McPhee, M. G., 1992: Turbulent heat-flux in the upper ocean under sea ice. 
    471                             Journal of Geophysical Research-Oceans, 97(C4), 5365-5379. 
    472                         </NS_Reference> 
    473                         <NS_Reference> 
    474                             Maykut G. A., M.G. McPhee, 1995: Solar heating of the Arctic mixed layer  
    475                             Journal of Geophysical Research-Oceans, 100(C12), 24691-24703. 
    476                         </NS_Reference> 
    477                     </NS_References> 
    478                 </NS_Component> 
    479                 <NS_Component><!-- Sea Ice Dynamics --> 
    480                     <NS_Name>Sea Ice Dynamics</NS_Name> 
    481                     <NS_ComponentType>Cryosphere</NS_ComponentType> 
    482                     <NS_Description> 
    483                         The sea ice velocity arises from a balance of windstress, ocean drag, coriolis and internal ice stresses. 
    484                         It is based on the viscous-plastic sea-ice rheology of Hibler (1979), and recommended for use in  
    485                         climate modelling by the Sea Ice Model Intercomparison Project [Kreyscher et al, 2000]. 
    486                         Convergence of ice is impeded or prevented when the ice is thick.  
    487                         The ice ridging scheme converts thinner ice to thicker ice, and if the ice is converging, the scheme 
    488                         ensures that enough ice ridges to keep the ice concentration equal or below 1 (Hunke and Lipscomb).    
    490                         Maximum compressive strength of ice per unit thickness is 2.00e+04 (N/m**2) 
    491                         Ice strength is smoothed to avoid instabilities at high northern latitudes polewards of 87.5 lat.. 
    492                         Ice velocities are filtered at high northern latiitudes to prevent excessive ridging and buildup of ice. 
    493                         The Quadratic ice-ocean drag coefficient is 1.50e-02 
    494                     </NS_Description> 
    495                     <NS_References> 
    496                         <NS_Reference> 
    497                             Hibler, W. D., 1979: Dynamic Thermodynamic Sea Ice Model. 
    498                             Journal of Physical Oceanography, 9(4), 815-846.                             
    499                         </NS_Reference> 
    500                         <NS_Reference> 
    501                             Kreyscher M et al., 2000: Results of the Sea Ice Model Intercomparison Project: 
    502                             Evaluation of sea ice rheology schemes for use in climate simulations  
    503                             Journal of Geophysical Research-Oceans, 105 (C5): 11299-11320.                              
    504                         </NS_Reference> 
    505                         <NS_Reference> 
    506                             Thorndike, A. S., D. A. Rothrock, G. A. Maykut et al., 1975: 
    507                             Thickness Distribution of Sea Ice. 
    508                             Journal fo Geophysical Research-Oceans and Atmosphereres, 80(33), 4501-4513. 
    509                         </NS_Reference> 
    510                         <NS_Reference> 
    511                             Flato, G. M. and W. D. Hibler, 1995: 
    512                             Ridging and strength in modeling the thickness distribution of arctic sea-ice. 
    513                             Journal of Geophysical Research-Oceans, 100 (C9), 18611-18626.                         
    514                         </NS_Reference> 
    515                         <NS_Reference> 
    516                             Lipscomb, W.H. and E. C. Hunke, 2004: Modeling sea ice transport using incremental remapping.  
    517                             Monthly Weather Review, 132 (6), 1341-1354. 
    518                         </NS_Reference> 
    519                     </NS_References> 
    520                 </NS_Component>                
    521             </NS_Component> 
    522             <NS_Component> 
    523                 <NS_Name>Atmos-Ocean Coupler</NS_Name> 
    524                 <NS_ComponentType>Coupler</NS_ComponentType> 
    525                 <NS_Description>  
    526                 </NS_Description> 
    527             </NS_Component> 
    528324        </NS_Model> 
    529325    </NS_CodeBase> 
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