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You can try the new MIR-enabled MARS client with:
You are encouraged to test this new version of the MARS client and report back any issues to advisory@ecmwf.int. |
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MIR stands for Meteorological Interpolation and Regridding and is a interpolation and regridding tool and library. This new piece of software is replacing the veteran EMOSLIB when it comes to perform those operations in MARS. Beyond this, MIR’s flexible design facilitates scalability improvements and additional features. These include efficiency gains, a high degree of user configurability, and support for a wider range of grids than in the current package.
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You can try the new MIR-enabled MARS client with:
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mars -m |
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Questions and Answers
Why are you changing?
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Default truncation values for "RESOL=AUTO" ("autoresol") have also changed. MIR uses a formula to truncate the spectral series to correspond to the equivalent linear Gaussian grid, replacing the fixed table used in EMOSLIB. Transformations to regular latitude-longitude grids then use an intermediate full (regular) Gaussian grid.
This diagram illustrates an example transformation going from T1279 to a regular lat-lon 1.0/1.0 grid. Depending on the values of RESOL and GRID, MIR MIR will follow different paths. As a reference, also the original EMOSLIB behaviour is described shown for each case:
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| Path | Keywords | MIR Behaviour | EMOSLIB Behaviour | |
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| GreenRed | RESOL=AVAUTO, GRID=1.0/1.0 | Default Behaviour. Transformation from T1279 to the corresponding intermediate reduced octahedral Gaussian O1280, before goingan intermediate F90 full (regular) Gaussian grid (with an automatic truncation to T179) followed by a grid-to-grid interpolation from the F90 grid to 1.0/1.0. | Default Behaviour. Direct transformation from T1279 to 1.0/1.0, with no truncation. | Redan automatic truncation to T213 according to EMOSLIB's truncation table |
| Green | RESOL=AUTOAV, GRID=1.0/1.0 | Transformation from T1279 to the | F90 full (regular) Gaussian grid (with an automatic truncation to T179) followed by a grid-to-grid interpolation from the F90 gridcorresponding intermediate reduced octahedral Gaussian O1280, before going to 1.0/1.0. | Direct transformation from T1279 to 1.0/1.0, with an automatic truncation to T213 according to EMOSLIB's truncation tableno truncation. |
| Blue | RESOL=179, GRID=F90, and then GRID=1.0/1.0 TODO: use the new keyword once it has been agreed | Transformation from T1279 to the F90 full (regular) Gaussian grid (with an automatic truncation to T179) followed by a grid-to-grid interpolation from the F90 grid to 1.0/1.0. | Same as in MIR, but a separate MARS request is needed for each of the two steps. |
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