Code used in "Storms regulate Southern Ocean summer warming"

Datasets are located at:

Figures

• figure-1.ipnyb
• figure-2.ipynb
• figure-3.ipynb
• figure-4.ipynb
• figure-5.ipynb

Datasets

Slocum glider

slocum_gridded.nc, slocum_sst_median_10m.nc, slocum_epsilon.nc and slocum_xld.nc

Processing steps:

1. Slocum processing done in slocum_processing_main.ipynb and follow these steps:

   • Runs process-slocum-mat-to-nc.py, which:
     • Reads in the data processed by the GEOMAR toolbox: soscexstorm2_final_1sec_v2.mat
     • Converts the .mat dictionary format to an xarray dataset and saves the data as slocum_processed.nc
   • Removes pressure and temeprature values that are below -5 (erroneous data)
   • Saves the data slocum_processed_L2.nc and dissipation and xld data as and slocum_epsilon.nc and slocum_xld.nc
   • Calculates the Slocum SST, by:
     • Filter out profiles where the minimum depth is below 10 m (keeps 99.78% of data)
     • Finds the median value between 0.5 m and 10 m for each profile
     • Save the data as slocum_sst_median_10m.nc

2. Grid the Slocum data to 1 m depth intervals in slocum_gridding.ipynb to make slocum_gridded.nc

Storm tracking

ec_centers_1981_2020.nc

Original storm track position were obtained from https://github.com/jlodise/JGR2022_ExtratropicalCycloneTracker and processed into a single netcdf file using process-loidse_storm_centers.ipnyb

ERA5

era5_storm_interstorm_periods_1981_2023_DJF.nc, ds_era5_vars.nc, ds_era5_flux.nc, era5_case_study.nc, mean_summer_winds_fluxes_1981_2023.nc

1. Download the ERA5 data using download_era5_data.ipynb which downloads and saves hourly files of the required ERA5 data
2. Convert the hourly ERA5 files in daily means using era5_hourly_to_daily.ipynb which is done to make down the line processing more efficient
3. Calculate the storm statisitics using the daily ERA5 files in this order:
   • Remove data where sea ice concentration is above 15%
   • Identify median storm and interstorm periods for a each season
   • Calculate total storm and interstorm days in a each sesaon
   • Calculate the mean wind speed and fluxes for storm and interstorm periods
   • Save the netcdf file as era5_storm_interstorm_periods_1981_2023_DJF.nc

Cloud Top Pressure

modis_ctt_ctp.nc

The MODIS Level-2 Cloud product was obtained from http://dx.doi.org/10.5067/MODIS/MYD06_L2.061. The raw .hdf files were processed into a daily composite using process-modis-CTP.ipynb. The final data containing the MODIS cloud top pressure for 4 January is saved as modis_ctt_ctp.nc.

EN4

EN.4.2.2.f.analysis.c14.*.nc, en4_monthly_mixed_layer_depth_median.nc

The mixed layer depth calculations using individual profiles and the gridding are done in process-en4-mld.ipynb. Profiles saved as en4_profiles_with_mixed_layer_depth.nc and gridded mld saved as en4_monthly_mixed_layer_depth_median.nc.

NOAA OI SST and sea ice

sie.csv, sst.mnmean.nc; lsmask.nc; icec.mnmean.nc

Southern Ocean Fronts

ACCfronts.csv

Southern Annular Mode

sam_ds.nc