# Data repository associated with the manuscript 'Greenland Ice Sheet ice slab expansion and thickening', Nicolas Jullien, Andrew J. Tedstone, Horst Machguth, Nanna B. Karlsson, Veit Helm (2023)

## Introduction:

If you are in a rush, the main files you may need are:
- Ice layer location over the GrIS in 2002-03: '2002_2003_green_excel.csv'
- Ice slabs thickness from 2010 to 2018: 'Ice_Layer_Output_Thicknesses_2010_2018_jullienetal2021_high_estimate_cleaned.csv'
- Shapefile of ice slabs extent in 2010-18: 'iceslabs_jullien_highend_20102018.(shp,cpg,dbf,prj,qpj,shx)'

Otherwise, we provide a short description of each file present in this data repository.

## Outputs:
### Flight lines:
'flightlines_20022018_GrIS.csv' in Flightlines20022018: all the flight lines of Accumulation Radar intersecting with the GrIS.

### 2002-2003:
In MatchedRadagrams_20022003:
	- In raw_radagrams:2002-03 accumulation radar data georeferenced after matching between timestep in radar data and timestep in master GPS file (see the Supplementary Materials of the manuscript for more information).
	- In L1_radargrams:2002-03 radargrams after surface picking, slices from 0 m down to 30 m depth (.png and .pickles files).
'ice_lenses_identification_MMMDD_YY_proc_ID.mat.png' or 'ice_lenses_identification_MMMDD_YY_ID_aggregated.png' in IndividualIceSlabsIdentification_20022018/20022003: radargram location on the GrIS (top) and 30m thick radargram with ice layers identification overlayed in colour (green = high confidence, yellow = medium confidence, red = low confidence, purple = near surface ice layer from previous summer. Note that we kept only the green identified ice layers) (bottom).
'metadata_coord_icelens_2002_2003_26022020.pickle' in AssociatedFiles: Python dictionary regrouping ice lens location (coordinates in EPSG:3413) in 2002-03 with corresponding colour code (1 = green, 0 = yellow, -1 = red, 2 = purple).
'2002_2003_green_excel.csv' in IceSlabs_20022018\20022003: ice layer location in 2002-03 on the GrIS. Coordinates are in EPSG:3413, elevation above ellipsoid WGS84.

### 2010-2018:
'Ice_Layer_Output_Thicknesses_2010_2018_jullienetal2021_high_estimate_cleaned.csv' in IceSlabs_20022018\20102018: high end estimate (ice identified in the quantile 0.65 from the ice distribution of the reference track) ice slab thickness from 2010 to 2018. Note that 2017-2018 data that were at lower elevations compared to the 2010-2014 ice slabs extent from MacFerrin et al., (2019) were discarded.
'iceslabs_jullien_highend_20102018.(shp,cpg,dbf,prj,qpj,shx)' in IceSlabs_20022018\20102018: shapefile of the hull defined manually around the high estimate 2010-2018 ice slabs mapping. 
'iceslabs_jullien_highend_2010_11_12.(shp,cpg,dbf,prj,qpj,shx)' in IceSlabs_20022018\20102018: shapefile of the hull defined manually around the high estimate 2010-11-12 ice slabs mapping. Lower elevations estimate based on 2010-2014 ice slabs extent from MacFerrin et al., (2019).
'Ice_Layer_Output_Thicknesses_2010_2018_jullienetal2021_low_estimate_cleaned.csv' in IceSlabs_20022018\20102018: low end estimate (ice identified in the quantile 0.79 from the ice distribution of the reference track) ice slab thickness from 2010 to 2018. Note that 2017-2018 data that were at lower elevations compared to the 2010-2014 ice slabs extent from MacFerrin et al., (2019) were discarded.
'iceslabs_jullien_lowend_20102018.(shp,cpg,dbf,prj,qpj,shx)' in IceSlabs_20022018\20102018: shapefile of the hull defined manually around the low estimate 2010-2018 ice slabs mapping.
'iceslabs_jullien_lowend_2010_11_12.(shp,cpg,dbf,prj,qpj,shx)' in IceSlabs_20022018\20102018: shapefile of the hull defined manually around the low estimate 2010-11-12 ice slabs mapping. Lower elevations estimate based on 2010-2014 ice slabs extent from MacFerrin et al., (2019).
'YYYYMMDD_ID_IDS_IDE_probability_iceslabs_presence_after_DF.png' in IndividualIceSlabsIdentification_20022018\20102018: Final individual ice slabs mapping from 2010 to 2018 as shades of grey (black = identification in the quantile 0.65 from the ice distribution of the reference track, lightest grey = identification in the quantile 0.79 from the ice distribution of the reference track).
'Ice_Layer_Output_Thicknesses_2010_2018_jullienetal2021_Fig3_high_estimate.csv' in IceSlabs_20022018\20102018\Fig3: Similar file as as 'Ice_Layer_Output_Thicknesses_2010_2018_jullienetal2021_high_estimate_cleaned.csv', but ice slabs larger than 16m thick were not discarded. Used for Fig. 3 generation.

## Used for data processing:
'binary_conservative_mask_20130409_01_010_012_XDEPTHCORRECT_AFTER.png' in AssociatedFiles\Mask20130409_01_010_012: manual mask differentiating ice slabs VS porous firn on the reference track 20130409_01_010_012.
'20130409_01_010_012_XDEPTHCORRECT_AFTER.png' in AssociatedFiles\Mask20130409_01_010_012: reference track 20130409_01_010_012 out from the function 'IceBridgeGPR_Manager_v2.py' on which was defined the manual mask differentiating ice slabs VS porous firn.
'20130409_01_010_012_probability_iceslabs_presence_after_DF.png' in AssociatedFiles\Mask20130409_01_010_012: reference track 20130409_01_010_012 after removal of the surface out from the function 'probabilistic_iceslabs.py' on which was applied the mask to extract the quantiles of ice radar signal strength. 
'reference_porousfirn_distrib.pickle' in AssociatedFiles\Mask20130409_01_010_012: Porous firn radar signal strength distribution of the reference track 20130409_01_010_012 after appliance of the mask.
'reference_iceslabs_distrib.pickle' in AssociatedFiles\Mask20130409_01_010_012: Ice content radar signal strength distribution of the reference track 20130409_01_010_012 after appliance of the mask.
'IceBridgeDB_2010_2018.h5' in AssociatedFiles: 2010-2018 database.