GUD IGSM numerical code and inputs

The model code is available at https://gitlab.com/jahn/gud Here we include: MITgcm_gud_igsm.tar - a tarball of the MITgcm, including the ecosystem, biogeochemical, and optical codes (pkg/gud, pkg/radtrans) and the specific modifications for the 51 plankton setup and the a climate change simulation (see monod5_igsm). runtime_file.tar - a tarball with the necessary run time parameter files. The two *.nml files include all the ecosystem/biogeochemical parameters used in this simulation The three *.txt files include the spectral absorption and scattering used in the simulations This simulations has been used in: Bardon, L., B.A. Ward, S. Dutkiewicz, and B.B. Cael. On predicting plankton biogeography with machine-learning methods. In revision for Geophysical Research Letters. Cael, B.B., S. Dutkiewicz and S.A. Henson. Abrupt shifts in 21st century plankton communities. In revision for Science Advances. Henson, S.A., S.R. Allen, B.B. Cael, and S. Dutkiewicz. Future phytoplankton diversity in a changing climate. In revision for Nature Communications.