In order to run all of these MATLAB scripts, you need raw data that you can find at the following address: csys/paleo1/pscholz/datafiles_zeitserLohmann_LGM. These data are the output data of the ocean model MPI-OM (temperature, salinity, max.mixed layer depth, sea level and velocities). The MPI-OM was forced by the results of the atmospheric model ECHAM 3 itself forced by sea-surface temperatures (SSTs) from three different climate background from the Last Glacial Maximum (LGM).
- First climate background: LGMO. It contains SSTs from the CLIMAP 1981 project.
- Second climate background: LGMN. It contains SSTs from the CLIMAP 1981 project with an additional cooling of 3°C in the tropics.
- Third climate background: LGMG. It contains SSTs from the GLAMAP 2000 project.
You will see that the MPI-OM shows an oscillatory regime for the NADW transport under such climate conditions. Within one cycle of these oscillations, the NADW transport stays in a weak mode (min. phase) and jumps abruptly to a strong mode (max. phase). So the MATLAB scripts are written to represent the state of the glacial Ocean during the weak and the strong modes of the NADW transport as well as the anomalies between these two states.
Extra: Output data from the MPI-OM are also available under present-day conditions (NCEP). In that case, the ocean model was directly forced by the climate data from the NCEP/NCAR reanalysis data. The raw data can be found at the following address: csys/paleo1/pscholz/datafiles_zeitserLohmann_NCEP
Then:
- let run the script: ocean_..._calc_..., it reformats and averages the raw data and if needed, calculates the parameters which are not direct outputs of the MPI-OM (density, MOC).
- Once this step is completed, the processed data are stored in .mat files. In the scripts: ocean_..._plot_..., you have to select the type of run (LGMN, LGMG, LGMO and NCEP) and the ocean region (ato, ata) so that the “plot” script can load the correct processed data. You also have to choose if you want absolute or anomaly profiles of the weak/strong mode of the NADW transport.
CAUTION: Please be careful and verify if the input parameters (ocean region, ocean variable, type of run, and the periods of the run) are the same as in the script that reformats the data (the scripts: ocean_..._calc_).
The functions named: “my_om_msec_gr30”, “ocean_zeitreihe_...”, “cfigure” … are sub functions that are needed to run the main programs.
Programmes can be found under
csys/paleo1/pscholz/bearbeitet_datafiles_LGMx
Data can be found under
csys/paleo1/pscholz/datafiles_zeitserLohmann_LGM