The mesoscale meteorological model MM5 (PSU/NCAR) is a model applicable to limited areas (not on global scale). It has the
possibility of running under hydrostatic and non-hydrostatic modes. The model has been designed by using sigma coordinates to
simulate and predict the mesoscale air circulation.
The MM5 has been developed by the University of the State of Pensilvania and the National Center for the Atmospheric
Research (NCAR) of Boulder (Colorado). The model is continuing to be improved due to contributions from many useres ariund the
world (Universities, laboratories, etc.)
The Fifth Generation of the Model of Mesoscale NCAR/Penn State (MM5) is the last version of a series of
developments that began in years 70. Since then the model has undergone continuous changes like:
Increase of physical options.
Model MM5 needs certain auxiliary programs for its complete yield. All this joint of programs along with the main modul
MM5 is what constitutes the modelling system MM5.
The relation between all these programs is in (figure 1, please click here to see the figure). This figure shows to the logical order of
execution of the programs as well as the data flows of
The terrestrial, meteorological and isobaric data, are interpolated horizontally by programs TERRAIN and DATAGRID
respectively, from a mesh of latitude-lengths to a variable domain of high-resolution. This interpolación can be carried
out by means of a projection type Mercator, Lambert or
The interpolación does not provide the sufficient level of detail, reason why the interpolated data can be improved
(program RAWINS) by means of the inclusion of observations of surface and radiosondages using for this aim the
technique of Cressman.
Program INTERP carries out the vertical interpolación from pressure levels to the system of coordinates sigma of the
The surfaces sigma near the ground faithfully follow the topography of the terrain, whereas in the high levels but they
tend to come near to the isobaric surfaces. Because as much the resolution as the size of the domain is variable, the
different programs from the model use parametrizaciones for the dimensions, requiring a variable amount of storage
Functions of the programs:
It defines the domain of the model and the projection of the map.
It generates the topography and uses of the ground in
the cells of the model.
It generates the First-Guess of all the fields of cells
of the model from the meteorological data set of entrance.
It develops the objective analysis: it combines the First-Guess of the fields of the model with
the radiosondages and the observations in surface.
It interpolates the data of pressure levels from RAWINS or DATAGRID to the sigma coordinates
of the model.
It shows the outputs of each one of the components of
It carries out the time integration.
The objective of the present Project is to execute and to study the Mesoscale Meteorological Model MM5 at the
Cray-YMP platform of the Supercomputer Center of Catalonia (CESCA) migrating it of its original platform in
the NCAR (National for Center Atmospheric Research) for its possible application to any domains, as
well as to incorporate it in a hierarchy of models that allow to improve the predictions on the quality of the air in
environments from continental to urban scales.
In order to carry out these objectives, we had to migrate the Fortran code of the model (more than 100,000 lines of code and
near 1000 subroutines) from the NCAR center, with his peculiarities as far as use of his own libraries, compiler and
calls to operating system, to a Cray-YMP machine with 4 processors of the CESCA. It had to know the philosophy
launching of all the components of the MM5 modeling system which are based on scripts C-Shell (use of queues, remote
procedure calls (RPC), configuration of variables, etc.) to be able to modify them and to adapt them to the new machine
Cray-YMP in which we tried to execute the model. The results are goiven in such a way that we have ready all scripts to run
properly the model in opoerational way.
Due to the later closing of the machine Cray-YMP of the CESCA, it was necessary to migrate the model to the IBM SP2
(with 48 nodes), also from CESCA, in which we left an
executed code for the main component of the program (MM5).
Also it has been put into operation, either for CRAY-YMP and IBM-SP2, the possibility of being able to
visualize the results predicted by model MM5 with tool VIS5D (when transforming the binary formats of output of the
MM5 to an format understood by the VIS5D). In addition, a complete work of documentation of the model has been done so that
it will allow to future students and users to carry out
changes and new implementations easily and shortly.
Main changes carried out in the source code:
-SIMULATION: CASE EUROPE (NESTED SPAIN)
DESIGN OF THE EXPERIMENT
The input datas of this simulation come from the IMTA (Mexican Institute of Technology of the Water). I would like to thank the
special contribution from Dr. J.A. Salinas who provided the input data to execute the MM5 main code in our machine.
This case of simulation covers good part with the European continent and in special with Spain. . The data are for 0000, 1200 and 0000
UTM of 29 and 30 of October of 1997.
(Figure 2, please click here to see the Figure) shows the domain where the simulations was run in this case. The configurations of the
domain for the case of EUROPE study will be described
Main domain (domain 1, approximately Europe):
Trim in the point 41,0 degrees N and 3,0 degrees W. The size of the grids is of 90 km and the dimensions of domain IX
(direction the North-South) and JX (East-West direction) are respectively of 30*30. It uses domain expanded for the
objective analysis. The expansion in all the faces of
the domain is of 360 km.
Nested domain 1 (domain 2, approximately Spain):
It has his origin in the mother domain. Domain 2 (figure 3, please, click here to see the Figure) has a size of grids of 30 km and their
dimensions are 25*22.
REFERRED DATA TO GROUND AND TOPOGRAPHY
Program TERRAIN must send with two domains according to figures 2,3 to obtain the data referred to the topography
and necessary uses of the ground for DATAGRID.
It is necessary to use the fields of first guess NMC and NAVY SST for DATAGRID. They obtain the first guess of the
fields in 10 levels of standard pressure. These levels of standard pressure are 1000, 850, 700, 500, 400, 300, 250, 200, 150
and 100 mb.
In RAWINS, 10 new levels of pressure are created: 950,
925, 900, 800, 750, 650, 600, 550, 450 and 350 mb.
Sigma coodinates at 23 vertical levels. These sigma levels are 1, 99, 98, 96, 93, 89, 85, 8, 75, 7, 65, 6, 55, 5, 45, 4, 35, 3, 25,
2, 15, 1, 0,05 and 0.0. It uses INTERP to obtain the file of conditions of contour for the initial domain 1 and fields for
domain 1 and 2 for 3 periods of time.
SIMULATION OF THE MODEL
The simulation of the MM5 begins to 0000 UTC of the 29 of October of 1997. Domain 2 simultaneously begins its
simulation that the main domain.The 30 of October finishes
the simulation of the model to 0000 UTC.
The following physical options in the simulation of the
MM5 were used:
- cloud Equations of Grell with explicit humidity for domain 1 and 2 (including simple ice in the explicit equation).
- Equation of radiation of Dudhia frequently of radiation of 30 minutes.
- vertical Diffusion of the humidity in clouds.
- Coriolis force for nonhydrostatic simulation.
- Blackdar Pbl.
- Effect of clouds in the radiation.
- Without considering the effects of the snow cover.
- Analysis of embroider in domain 1. Non-Fdda in
The simulation with these configuration and input datas, took place in a IBM-SP2 with 48 nodes in the Supercomputer Center of
Catalonia (CESCA). The simulated time was was of 1440 minutes (24 hours). The CPU time required for this simulation was of 30
minutes and 34 seconds.
VISUALIZATION OF RESULTS WITH VIS5D
See Figures 4
, 5, 6
, 7, 8.
(PLease, click on the numbers to see the visualization results).
We would like to thank the following institutions
and persons for his/her collaboration to carry out this project:
- CESCA: Use of machines Cray-YMP and IBM-SP2.
- NCAR Wei Wang: Support in all the doubts on any component
of the model
-IMTA (Mexican Institute of Technology of the Water) D. José Antonio Salinas: Input data of
-Steve Emerson: Ordered to give support to the installation of library NETCDF
To see an Spanish version of the PowerPoint presentation, click here