RGI version 7 in OGGM

RGI version 7 in OGGM#

As of v1.6.3, OGGM supports a complete modelling workflow with RGI version 7. The outlines can be used to create glacier directories, and we have prepared pre-processed directories for both the “glacier” and “glacier-complex” products. To do so, we had to make a few simplifications and assumptions because RGI7 currently lacks two necessary external products: reference ice thickness and geodetic mass balance estimates.

Therefore, the following methodology was used to overcome these limitations:

  • we calibrated OGGM using the regional mass-balance estimates from Hugonnet et al., (2021), assuming the regional average is constant for all glaciers in a region (as done in Zekollari et al., 2024). This is a relatively strong assumption.

  • For the ice volume, we applied regional GlenA values obtained by calibrating OGGM with RGI6 to the Farinotti et al., (2017) estimates. As a result, any volume differences between RGI6 and RGI7 arise solely from updated glacier outlines, not data or methods changes.

  • Finally (less critical, but useful), we aggregated the RGI7G results to the glacier-complex level and re-ran the inversion on RGI7C, tuning it to match the RGI7G totals. This allows us to produce ice-thickness maps at the glacier complex scale without artefacts.

The resulting glacier directories can be accessed as shown below.

# Libs
import matplotlib.pyplot as plt
import xarray as xr

# Locals
import oggm.cfg as cfg
from oggm import utils, workflow, graphics

RGI7G: “Glacier” product#

# Initialize OGGM and set up the default run parameters
cfg.initialize(logging_level='WARNING')  # print less log messages than the default

# Local working directory (where OGGM will write its output)
cfg.PATHS['working_dir'] = utils.gettempdir('OGGM_rgi7_run', reset=True)

# Aletsch
rgi_ids = ['RGI2000-v7.0-G-11-02596']

# Go - get the pre-processed glacier directories
# You have to explicitly indicate the url from where you want to start from
base_url = 'https://cluster.klima.uni-bremen.de/~oggm/gdirs/oggm_v1.6/L3-L5_files/2025.6/elev_bands/W5E5/regional_spinup/'
gdirs = workflow.init_glacier_directories(rgi_ids, from_prepro_level=3, prepro_base_url=base_url,
                                          prepro_rgi_version='70G', prepro_border=10)
gdir = gdirs[0]

2026-04-11 17:37:33: oggm.cfg: Reading default parameters from the OGGM `params.cfg` configuration file.
2026-04-11 17:37:33: oggm.cfg: Multiprocessing switched OFF according to the parameter file.
2026-04-11 17:37:33: oggm.cfg: Multiprocessing: using all available processors (N=4)
2026-04-11 17:37:34: oggm.workflow: init_glacier_directories from prepro level 3 on 1 glaciers.
2026-04-11 17:37:34: oggm.workflow: Execute entity tasks [gdir_from_prepro] on 1 glaciers

graphics.plot_domain(gdir)
../../_images/73020ab14aaba45900926ae094094e48fbf23714ecffb12da96118e8b43ea44d.png

RGI7C: “Glacier complex” product#

# Aletsch complex
rgi_ids = ['RGI2000-v7.0-C-11-01323']

# Go - get the pre-processed glacier directories
# You have to explicitly indicate the url from where you want to start from
base_url = 'https://cluster.klima.uni-bremen.de/~oggm/gdirs/oggm_v1.6/L3-L5_files/2025.6/elev_bands/W5E5/regional_spinup/'
gdirs = workflow.init_glacier_directories(rgi_ids, from_prepro_level=3, prepro_base_url=base_url,
                                          prepro_rgi_version='70C', prepro_border=10)
gdir = gdirs[0]

2026-04-11 17:37:40: oggm.workflow: init_glacier_directories from prepro level 3 on 1 glaciers.
2026-04-11 17:37:40: oggm.workflow: Execute entity tasks [gdir_from_prepro] on 1 glaciers

graphics.plot_domain(gdir)
../../_images/c1a4e15307a1ea06ac79e6cc6f8836d78b8afea01e99b8e6c959e3c5a7db81fc.png