Module oggm_shop
This IGM module utilizes OGGM utilities and the GlaThiDa dataset to prepare data for the IGM model for a specific glacier given its RGI ID (parameter RGI_ID). You can check the GLIMS Viewer to find the RGI ID of your glacier. By default, IGM references RGI 7.0C, which can be found here. Altering the RGI_product parameter ('C' for glacier complex or 'G' for individual glacier) allows you to switch between these options. By default, data is preprocessed (preprocess parameter is set to True) with a spatial resolution of 100 meters and a border size of 30 meters. To customize the spatial resolution and the size of the 'border' to maintain a safe distance from the glacier margin, you need to set the preprocess parameter to False, and then set the dx and border parameters as desired.
When this module is executed, it automatically downloads a suite of data (refer to the table above) associated with the specified glacier (individual or complex). These data are stored in a directory named after the RGI ID within the data folder. Subsequently, a file named input.nc is created, containing the relevant variables renamed according to IGM's naming conventions.
Important: The oggm_shop module must be followed by the local inputs module, which reads data/input.nc and loads the 2D gridded variables as TensorFlow objects in IGM.
If IGM is run a second time, it will not re-download the OGGM data or recreate data/input.nc as long as the data remain in the data folder. This is particularly useful for parameter analysis, as it avoids redundant data downloads during multiple runs. The oggm_shop module provides all the necessary data variables required to run IGM for forward glacier evolution simulations, assuming the availability of basal topography (topg) and ice thickness (thk).
Additionally, it supports preliminary data assimilation and inverse modeling tasks within the iceflow module. These tasks typically involve variables such as icemaskobs, thkinit, uvelsurf, vvelsurf, thkobs, and usurfobs.
Data available via the shop are listed in the table below. Users can specify the source for ice thickness using the thk_source parameter (options: millan_ice_thickness or consensus_ice_thickness dataset) and for ice velocities using the vel_source parameter (options: millan_ice_velocity or its_live dataset).
Set include_glathida to True to retrieve the GlaThiDa ice thickness profiles for data assimilation purpose. When using RGI 6.0, these profiles are sourced from the GlaThiDa repository. For RGI 7.0, GlaThiDa data specific to the glacier, identified by its RGI ID, are retrieved from the OGGM server. These data are saved as a text file named glathida_data.csv in the module's download directory. In both cases, the data are read, rasterized with the label thkobs, and any pixels lacking observations are marked with NaN values.
| Variable | Reference |
|---|---|
| Ice thickness profile | GlaThiDa |
| ----------------------- | ---------------------------------------- |
| Surface DEM | Copernicus DEM GLO-90 |
| Ice thickness | Millan et al. (2022) |
| Ice thickness | Farinotti et al. (2019) |
| Surface ice speeds | Millan et al. (2022) |
| Surface ice speeds | its-live.jpl.nasa.gov |
| Glacier mask | Randolph Glacier Inventory |
| Ice thickness profile | GlaThiDa |
| Glacier change | Hugonnet et al. (2021) |
| Climate data | GSWP3_W5E5 |
| Flowline | OGGM |
Table: Products available with the oggm_shop module.
The module depends (of course) on the oggm library. Unfortunately the module works on linux and Max, but not on windows (unless using WSL).
Contributors: F. Maussion, G. Jouvet, E. Welty (GlaThiDa-related code), S. Cook (RGI 7.0 modifications).
Config Structure
oggm_shop:
RGI_ID: "RGI60-11.01450"
RGI_IDs: ["RGI60-11.01450"]
preprocess: True
dx: 100
border: 30
thk_source: consensus_ice_thickness
vel_source: millan_ice_velocity
incl_glathida: False
path_glathida: ""
filename: input.nc
remove_RGI_folder: True
sub_entity_mask: False
smooth_obs_vel: True
highres: False
Parameters
| Name | Type | Units | Description | Default Value |
|---|---|---|---|---|
| RGI_ID | str | dimless | RGI ID of the selected glacier, G stands for individual Glacier, and C for glacier Complex for RGI7 | RGI60-11.01450 |
| RGI_IDs | list | dimless | List of RGI IDs of the selected glaciers, G stands for individual Glacier, and C for glacier Complex for RGI7 | ['RGI60-11.01450'] |
| preprocess | bool | dimless | Use OGGM preprocessing if you are fine with given spatial resolution and border size | True |
| dx | float | m | Spatial resolution (need preprocess false to change it) | 100 |
| border | int | dimless | Safe border margin, number of pixels, (need preprocess false to change it) | 30 |
| thk_source | str | dimless | Millan ice thickness (millan_ice_thickness) or consensus ice thickness (consensus_ice_thickness) | consensus_ice_thickness |
| vel_source | str | dimless | Source of the surface velocities (millan_ice_velocity or its_live) | millan_ice_velocity |
| incl_glathida | bool | dimless | Set this to True for retrieving the GlaThiDa ice thickness profiles for the inversion. | False |
| path_glathida | str | dimless | Path where the Glathida Folder is stored, so that you don't need to redownload it at every use of the script, if empty it will be in the home directory (only relevant for RGI6.0) | |
| filename | str | dimless | NetCDF input data file created by OGGM | input.nc |
| remove_RGI_folder | bool | dimless | Remove RGI folder | True |
| sub_entity_mask | bool | dimless | Ice mask shows individual RGI 7.0G entities within each larger RGI 7.0C complex | False |
| smooth_obs_vel | bool | dimless | Smooth the observed velocities | True |
| highres | bool | dimless | Use high resolution data | False |