DOI: 10.5281/zenodo.16874967
title: Re-gridded Geothermal Heat Flow data sets (Supplementary material for Lösing et al. (2025): Community Heat Flow Recommendations: Suitable Basal Boundary Conditions for Greenland and Antarctica in ISMIP7.)

description: These datasets are supplementary material to the publication from Lösing et al., (2025): Community Heat Flow Recommendations: Suitable Basal Boundary Conditions for Greenland and Antarctica in ISMIP7. 

When using these data, please cite the original datasets and papers, as well as the accompanying publication. 

The Colgan & Wansing (2021) data has been reprojected to Polar Stereographic (EPSG:3413) and upsampled to the resolution BedMachine Greenland v5 (150 m; Morlighem et al., 2017, 2022) using bilinear interpolation. 

The Stål et al. (2020) and Lössing & Ebbing (2021) datasets have been reprojected to Antarctic Stereographic (EPSG:3031) when needed and have been upsampled to BedMachine Antarctica v3 (500 m; Morlighem et al.,2022) using bilinear interpolation. 

The original Aq1 dataset from Stål et al. (2020), including uncertainty metrics, was cropped at the coastline and grounding line due to the extent of some observables used. To facilitate regridding, we applied a buffered nearest neighbour extrapolation technique to create a processed version of the dataset (aq1_nn_extrapol.nc). We created a spatial buffer extending 4 grid cells (equivalent to 80 km given the 20×20 km resolution) around the valid values in Aq1 using morphological dilation with a circular kernel. We then applied nearest neighbour extrapolation to fill all NaN values across every variable in the dataset, followed by masking to retain only the extrapolated values within the 80 km buffer zone. This approach preserves the original model while adding a controlled "corona" of extrapolated values that extends smoothly into previously undefined regions, reducing edge effects and discontinuities that could occur during regridding procedures.

We further include topographic correction fields from Colgan et al. (2021). 

References:

Colgan, William; Wansing, Agnes, 2021, "Greenland Geothermal Heat Flow Database and Map", https://doi.org/10.22008/FK2/F9P03L, GEUS Dataverse, V2

Colgan, William, Joseph A. MacGregor, Kenneth D. Mankoff, Ryan Haagenson, Harihar Rajaram, Yasmina M. Martos, Mathieu Morlighem, Mark A. Fahnestock, and Kristian K. Kjeldsen. "Topographic correction of geothermal heat flux in Greenland and Antarctica." Journal of Geophysical Research: Earth Surface 126, no. 2 (2021): e2020JF005598. doi: 10.1029/2020JF005598

Lösing, Mareen; Ebbing, Jörg (2021): Predicted Antarctic Heat Flow and Uncertainties using Machine Learning [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.930237

Morlighem, M., Williams, C., Rignot, E., An, L., Arndt, J. E., Bamber, J. L., Catania, G., Chauché, N., Dowdeswell, J. A., Dorschel, B., Fenty, I., Hogan, K., Howat, I., Hubbard, A., Jakobsson, M., Jordan, T. M., Kjeldsen, K. K., Millan, R., Mayer, L., Mouginot, J., Noël, B., O'Cofaigh, C., Palmer, S. J., Rysgaard, S., Seroussi, H., Siegert, M. J., Slabon, P., Straneo, F., van den Broeke, M. R., Weinrebe, W., Wood, M. & Zinglersen, K.. 2017. BedMachine v3: Complete bed topography and ocean bathymetry mapping of Greenland from multi-beam echo sounding combined with mass conservation. Geophysical Research Letters. 44. DOI: 10.1002/2017GL074954.

Morlighem, M. et al. (2022). IceBridge BedMachine Greenland. (IDBMG4, Version 5). [Data Set]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/GMEVBWFLWA7X. 

Morlighem, M. (2022). MEaSUREs BedMachine Antarctica. (NSIDC-0756, Version 3). [Data Set]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/FPSU0V1MWUB6.  

Stål, Tobias; Reading, Anya M; Halpin, Jacqueline A; Whittaker, Joanne (2020): Antarctic geothermal heat flow model: Aq1 [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.924857