Dataset associated with paper "Topographic hotspots of Southern Ocean eddy upwelling"

Data repository for Yung, Morrison and Hogg (2022) Topographic hotspots of Southern Ocean eddy upwelling, submitted to Frontiers in Marine Science

 

This repository contains processed data, created using scripts available in the github repository https://github.com/claireyung/Topographic_Hotspots_Upwelling-Paper_Code.

 

The data comes from the repeat year atmospheric forcing version of the ACCESS-OM2 modelling suite 0.1 degree model (see Kiss et al. (2020), http://www.cosima.org.au, model available at https://github.com/COSIMA/access-om2). The model was spun up for 270 years, and the next 10 years of output were used.

 

Daily resolution data was used in the calculation of quantities, which results in a large amount of raw data (~4TB for Southern Ocean latitudes (35-70S), 10 years). Therefore, we only provide relevant processed data. Details of these calculations are available in the above github repository.

 

Any quantities calculated along sea surface height contours are labelled with a letter. These are referred to in the following table.

 

| Letter |  SSH  |

| :---:  | :---: |

|   A    | -0.1m |

|   B    | -0.2m |

|   C    | -0.3m |

|   D    | -0.4m |

|   E    | -0.5m |

|   F    | -0.6m |

|   G    | -0.7m |

|   H    | -0.8m |

|   I    | -0.9m |

|   J    | -1.0m |

|   K    | -1.1m |

|   L    | -1.2m |

|   M    | -1.3m |

|   N    | -1.4m |

|   O    | -1.5m |

|   P    | -0.15m|

|   Q    | -0.25m|

|   R    | -0.35m|

|   S    | -0.45m|

|   T    | -0.55m|

|   U    | -0.65m|

|   V    | -0.75m|

|   W    | -0.85m|

|   X    | -0.95m|

|   Y    | -1.05m|

|   Z    | -1.15m|

|   Z1   | -1.25m|

|   Z2   | -1.35m|

|   Z3   | -1.45m|

 

There are two versions of the along-contour coordinates for each contour. The latlon named files are more useful for analysis, the other is used while computing transport across contours. These are made using https://github.com/claireyung/Topographic_Hotspots_Upwelling-Paper_Code/blob/main/Analysis_Code/make_contour.ipynb.

 

Distance along contour files contain the cumulative distance along the contour in 10^3 km from 80E (https://github.com/claireyung/Topographic_Hotspots_Upwelling-Paper_Code/blob/main/Figure_Code/Fig7-upwelling_characteristics.ipynb). Dimensions are contour index, counting from 80E. There are also segment length files of each part of the contour.

 

vh_eddy files contain the eddy transport across the contours, averaged over 10 years. These are calculated by taking the time mean of the residual transport (\(\overline{vh}\)), e.g. SO_L_vol_trans_across_contour_binned.nc, and subtracting the mean transport \(\overline{v}\overline{h}\), calculated from the time mean isopycnal thicknesses along contours (e.g. SO_L_dzu_across_contour_binned) and the time mean velocity, \(v = vh/h\) (calculated in https://github.com/claireyung/Topographic_Hotspots_Upwelling-Paper_Code/blob/main/Analysis_Code/Save_and_bin_along_contours.ipynb). The full files are provided for the contour L (SSH=-1.2 m) as is provided in the paper manuscript Fig. 6. These eddy transports have dimensions of sigma1 and contour index (the two extra SO_L files have time too).

 

vh_eddy_interp files contain the interpolated eddy transports at hotspots, for the density range 1032.2kg/m^3 <= sigma_1 <= 1032.5kg/m^3. Calculation method provided at https://github.com/claireyung/Topographic_Hotspots_Upwelling-Paper_Code/blob/main/Analysis_Code/Interpolation_between_contours.ipynb.

 

We also provide files that summarise the transport in density and SSH space for hotspots and the circumpolar total. See https://github.com/claireyung/Topographic_Hotspots_Upwelling-Paper_Code/blob/main/Analysis_Code/UpwellingArmDefn.ipynb for calculation details. The exact names and specifications are provided in the README.

 

We provide 10 year mean files of the energy conversion and energy terms over the Southern Ocean latitude range. These are made by binning daily transports and layer thicknesses into sigma 1 bins over the Southern Ocean (https://github.com/claireyung/Topographic_Hotspots_Upwelling-Paper_Code/blob/main/Analysis_Code/Binning_SouthernOcean_code.ipynb) and then calculating energy terms (https://github.com/claireyung/Topographic_Hotspots_Upwelling-Paper_Code/blob/main/Analysis_Code/Save_MKE_EKE.ipynb, https://github.com/claireyung/Topographic_Hotspots_Upwelling-Paper_Code/blob/main/Analysis_Code/Save_Energy_Conversion_Terms.ipynb)

 

 

The files named with contour_energies contain the EKE, Form stress and Reynolds stress averaged over 10 years but extracted along the same contours as eddy transport. https://github.com/claireyung/Topographic_Hotspots_Upwelling-Paper_Code/blob/main/Analysis_Code/save_energy_terms_along_contours.ipynb

 

We also provide 10 year averaged density binned transport, layer thickness and densities.

 

Please refer to the README file for additional details.