Scripts used to produce the data and figures for the ARC3O Part 2

What's this?

These are the scripts used to prepare the data and produce figures for the paper:

Burgard, C., Notz, D., Pedersen, L. T., and Tonboe, R. T.: The Arctic Ocean Observation Operator for 6.9 GHz (ARC3O) – Part 2: Development and evaluation, The Cryosphere, 14, 2387–2407, https://doi.org/10.5194/tc-14-2387-2020, 2020.

The best understanding of these scripts is reached by combining the following description with the content of the paper. Enjoy!

If you are interested in the ARC3O code in particular, visit this github repository, which contains the most up-to-date ARC3O-version.

Data

All following data and the corresponding documentation can be downloaded from the DKRZ long term archive.

Model data

The ECHAM output needed for the brightness temperature simulation, from assimilation runs conducted by F. Bunzel for Bunzel et al. (2016) can be found in the folder assimilation_runs.tar.gz in the DKRZ long term archive.

Simulation data

The simulated brightness temperatures were computed by applying the version of ARC3O given in the folder arc3o to the output of the three different MPI-ESM assimilation runs: * SICCI2: run_arc3o_SICCI.ipynb * Bootstrap: run_arc3o_Bootstrap.ipynb * NASA Team: run_arc3o_NASATeam.ipynb

As the results are written out as monthly files, you can merge them using cdo as follows:

mkdir mergetime
cdo mergetime TBtot* ./mergetime/TBtot_assim_2003-2008_7.nc

The output data can be found in the folder simulated_TBs.tar.gz in the DKRZ long term archive.

Observation data

The AMSR-E data was downloaded from the NSIDC website and merged and remapped to the MPI-ESM grid with the script rearrange_AMSR_data.sh.

The Round Robin Data Package used in Sec. 3.1.4 was downloaded from https://doi.org/10.6084/m9.figshare.6626549.v6.

The sea-ice concentration products used in Figures_6_8.ipynb.ipynb were downloaded from NSIDC (ftp://sidads.colorado.edu/pub/DATASETS/NOAA/G02202_V3/north/daily/, Bootstrap and NASA Team) and ESA CCI project. The data were merged, remapped to the MPI-ESM grid, and the pole hole cut out using cdo.

In both observed and modeled brightness temperatures, the polar hole was masked using cdo as follows:

cdo sellonlatbox,0,360,45,87.2 infile.nc infile_hole.nc

The formatted observational data can be found in the folder observations.tar.gz in the DKRZ long term archive.

Sensitivity study (see Sec. 4.3.2 of the paper)

For the sensitivity study in Sec. 4.3.2., we prepare the variability ranges displayed in Figure B1 and mentioned in Table 1 with the script prepare_sens_ranges.sh. The resulting modulated fields are used to run simulations with ARC3O, using the script prepare_sensexp_data.py. Finally, these results are processed to prepare the results displayed in Figure 5 and Table 1 with the script prepare_sensexp_output_for_figure5.sh.

Further analysis and Figures

The final analysis and visualization was done using the following scripts:

• Figure 2: Figure_2.ipynb
• infer the atmospheric influence for the correction of the summer TB: infer_atmospheric_influence.ipynb and infer_atmos_influence_analysis.sh
• Figure 4 and key figure (on The Cryosphere webpage): Figure_Key_and_4.ipynb
• Figure 5, Table 1, and Figure B1: Figures_B1_5_Table_1.ipynb
• Figures 6 and 8: Figures_6_8.ipynb.ipynb
• Figure 7: Figure_7.ipynb
• Figure A1: Figure_A1.ipynb
• Figure 9: data prepared with experiment_meltpondfraction0.ipynb and mpf0_prepare_files.sh, then plotted with Figure_9.ipynb

Signed: Clara Burgard, 02.09.2020