debris_cover_smb

Tools and notebooks for computing Surface Mass Balance (SMB) over debris-covered glaciers from remote sensing products

Figure 1: Schematic of steps to compute Lagrangian Surface Mass Balance from DEM differencing. Eulerian/Lagrangian graphics are copyright flowillustrator. WorldView satellite logo are copyright Maxar.

Table of contents

• Functions Library

  • glac_dyn.py: functions for flow correction, mass balance computation, and statistics computation
  • constants.py: commonly used variables and data management
  • geospatial.py: basic geospatial functions

• Scripts

  • compute_glacier_smb.py: Wrapper script to compute SMB from DEMs and velocity maps
  • disp_mgm_corr.py: Wrapper script to compute velocity maps from pairs of shaded relief maps

• Analysis Notebooks

  • download_supporting_data.ipynb: Utilities to download ancillary data (e.g., ice thickness, debris thickness)
  • icethickness_sensitivity.ipynb: Assess flux divergence sensitivity due to ice thickness
  • Cliff_sensitivity_analysis.ipynb: Confusion matrix analysis for ice cliffs maps, Black Changri Nup Glacier
  • propagate_uncertainty_upgraded_formula.ipynb: Uncertainty estimation and uncertainty figure generation
  • Glacier_description_table.ipynb: Compile statistics for the study sites glacier stats table
  • Vel_DhDt_uncertainty.ipynb: Uncertainty estimates for velocity and Lagrangian DhDt products
  • Flux_check.ipynb: Verify volume conservation before and after application of adaptive Gaussian filtering
  • ChangriNup_annual_paper.ipynb: Black Changri Nup Annual SMB estimation
  • Hugonnet_et_al_contribution_by_hma.ipynb: Contribution by HMA glaciers to SLR from Hugonnet et al. 2021 used for introduction section in the current study

• Figure Notebooks

  • SMB_maps.ipynb: Multi-panel SMB maps
  • SMB_profile.ipynb: Supplementary SMB profile figure
  • StudyArea.ipynb: Panels for study area figure
  • adaptive_filter_figure.ipynb: Adaptive filter illustration figure
  • changrinup_seasonal.ipynb: Black Changri Nup seasonal maps
  • imja_zoomin_highres.ipynb: Zoom-in panels for Imja Glacier
  • khumbu_zoomin_highres.ipynb: Zoom-in panels for Khumbu Glacier
  • summary_figure.ipynb: Ice cliff summary figure
  • lirung_ts.ipynb: Lirung Glacier seasonal time series

• Processing Notebooks

  • velocity_cleanup: Notebooks to remove velocity anomaly and fill gaps using Gaussian filters

• Document to produce SMB maps step by step

Contact us

If you would like to use the tools for applying Lagrangian elevation change to your study site, please feel free to reach out to Shashank Bhushan ([email protected]) :D

Citation

The code in this repository was developed for the under-review manuscript:

• Bhushan S, Shean D, Hu JM, Guillet G, Rounce DR (2024). Deriving seasonal and annual surface mass balance for debris-covered glaciers from flow-corrected satellite stereo DEM time series. Journal of Glaciology 1–22. https://doi.org/10.1017/jog.2024.57