FLEXPART at ECMWF

The FLEXPART environment

At ECMWF version 902 of FLEXPART is centrally installed on ecgate, ATOS and on some internal Linux-based systems. On these systems (with the exception of ATOS) Metview is configured to pick up the FLEXPART location automatically via these environment variables:

  • MV_FLEXPART_EXE: defines the FLEXPART executable

  • MV_FLEXPART_RESOURCES: specifies the directory containing the following files IGBP_int1.dat, OH_7lev_agl.dat, surfdata.t and surfdepo.t

  • MV_FLEXPART_SPECIES: specifies the directory containing the species

On the ATOS supercomputer you need to set these variables manually for your Metview session.

Hard-coded parameters

Some of the important FLEXPART parameters cannot be specified at run time but are hard-coded in the source. The FLEXPART installation at ECMWF uses the following set of hard-coded parameters:

Description

Value

Parameter in source

Source file

Maximum number of grid points in E-W (input grid)

1441

nxmax

par_mod.f90

Maximum number of grid points in N-S (input grid)

721

nymax

par_mod.f90

Maximum dimension of (u,v) wind fields in z direction (input grid)

138

nuwzmax

par_mod.f90

Maximum dimension of (w) wind fields in z direction (input grid)

138

nwzmax

par_mod.f90

Maximum dimension in z direction (input grid)

138

nzmax

par_mod.f90

Maximum number of species

6

maxspec

par_mod.f90

Maximum number of particles

2000000

maxpart

par_mod.f90

Maximum number of age classes

10

maxageclass

par_mod.f90

Maximum number of receptor sites

200

maxreceptors

par_mod.f90

Maximum number of output grid nests

0

maxnests

par_mod.f90

Compilation

compiler: gfortran compilation options:

-O3 -m64 -mcmodel=medium -fconvert=little-endian -frecord-marker=4

Necessary code modifications

To make FLEXPART work at ECMWF the following modifications had to be made in the source code:

  • Resolve type mismatch in err.f90 with newer gfortran compiler: see flextra ticket49

    This involved the modification in err.f90 of line 106 and 111

    ../../../../_images/image1.png

    and line 140 and 145 as well.

    ../../../../_images/image2.png

  • Make FLEXPART work for 137 model levels

    In par_mod.f90 line 125 had to be modified:

    ../../../../_images/image3.png

Additional code modifications

We changed the code to increase the maximum value of some parameters.

  • Increase maximum number of age classes

    In par_mod.f90:

    ../../../../_images/image41.png

  • Increase maximum number of species

    In par_mod.f90:

    ../../../../_images/image5.png