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As part of the efforts in the CMDV project, interfaces to integrate the MOAB unstructured mesh library with the TempestRemap remapping tool have been undertaken. Detailed information on the algorithmic and implementation aspects of this effort have been written in a manuscript submitted to Geoscientific Model Development [1]. This work has led to the development of a new offline remapping tool called mbtempest, which exposes the functionality to compute the supermesh or intersection mesh between two unstructured source and target component grids, in addition to using this supermesh for computing the remapping weights to project solutions between the grids. This functionality is part of the critical worflow with E3SM, where the generated remapping weights in the offline step are consumed by MCT at runtime to seamlessly transfer solution data between components (atm↔ocn, atm↔lnd, etc).

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1. MPI-enabled C, C++, and Fortran compiler wrappers that are exported in the local environment as $CC, $CXX, and $FC.
2. Next, verify installations of dependent libraries such as $HDF5_DIR and $NETCDF_DIR that have been compiled with MPI support using the $CC, $CXX, $FC compilers.
3. Get Eigen3 package from the webpage and untar to the $INSTALL_PREFIX/eigen3 directory with the following command
   1. Download: wget https://bitbucket.org/eigen/eigen/get/3.3.7.tar.gz  OR  curl https://bitbucket.org/eigen/eigen/get/3.3.7.tar.gz -O
   2. Move: mv eigen-eigen* $INSTALL_PREFIX/eigen3
   3. export EIGEN3_DIR=$INSTALL_PREFIX/eigen3

Dependencies and pre-requisites from an existing E3SM use case

It is recommended to use the same dependent libraries as a regular E3SM case. 
E3SM cases save the environment in files like  .env_mach_specific.sh in the case folder. That is a good environment to start building your tempestremap, MOAB or Zoltan dependencies. Or maybe they are already built on your machine.  That environment is created from config_machines.xml or config_compiler.xml files, and these change all the time, as new releases, use cases and tests become available. Problems can appear for MOAB's mbtempest if the HDF5 library that netcdf4 is built on does not have a good MPI support. Or if (gasp!) hdf5 is built in serial. Then you are limited on building mbtempest without parallel support, which means you are better off by just running tempestremap in serial. Do not bother with building MOAB. 
On compy, the netcdf used for E3SM is built with serial hdf5, so it cannot be used for MOAB. This is why on compy we have a separate netcdf, built with parallel hdf5. 

Build

To get the entire (MOAB-TempestRemap) stack working correctly, we need to find parallel-enabled dependency installations for HDF5 and NetCDF that are built with MPI library support for the current architecture

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If steps (a)-(g) pass successfully, the MOAB libraries and tools, along with interfaces for TempestRemap will be installed in $INSTALL_PREFIX/moab directory. The offline remapping weight computation tool, mbtempest, will also be installed during this process and can then be used standalone to generate the weight files as needed.

References

1 Mahadevan, V. S., Grindeanu, I., Jacob, R., and Sarich, J.: Improving climate model coupling through a complete mesh representation: a case study with E3SM (v1) and MOAB (v5.x), Geosci. Model Dev. Discuss., https://doi.org/10.5194/gmd-2018-280, in review, 2018.