# Version history¶

## v1.X (unreleased)¶

### Breaking changes¶

• Accumulation Area Ratio (AAR) is now correctly computed (GH361). By Fabien Maussion.
• The method used to apply CRU and GCM anomalies to the climatology has changed for precipitation: we now use scaled anomalies instead of the standard anomalies (PR393). The previous method might have lead to negative values in some cases. The corresponding reference t* have also been updated (PR407). This change has some consequences on the the model results: cross-validation indicates very similar scores, but the influence on global model output has not been assessed yet. By Fabien Maussion.
• It is now possible to run a simulation with spinup in the standard workflow (PR411). For this to happen it was necessary to clean up the many *filesuffix options. The new names are more explicit but not backwards compatible. The previous filesuffix is now called output_filesuffix. The previous input_filesuffix is now called climate_input_filesuffix. The random_glacier_evolution task is now called run_random_climate for consistency with the other tasks See the PR linked above for more info. By Fabien Maussion.
• RGI version 4 isn’t supported anymore (GH142). By Fabien Maussion.

### Enhancements¶

• Added a utility function to easily get intersects files (PR402). By Fabien Maussion.
• The old GlaThiDa file linking the total volume of glaciers (T database) to RGI has been updated to RGI Version 6 (PR403). Generally, we do not recommend to use these data for calibration or validation because of largely unknown uncertainties. By Fabien Maussion.
• The computing efficiency of the 2D shallow ice model has been increased by a factor 2 (PR415), by avoiding useless repetitions of indexing operations. The results shouldn’t change at all. By Fabien Maussion.
• Added optional shape factors for mass-conservation inversion and FluxBasedModel to account for lateral drag dependent on the bed shape (PR429). Accepted settings for shape factors are None, ‘Adhikari’ (Adhikari & Marshall 2012), ‘Nye’ (Nye, 1965; equivalent to Adhikari) and ‘Huss’ (Huss & Farinotti 2012). Thorough tests with applied shape factors are still missing. By Philipp Gregor.
• Some amelioration to the mass-balance models (PR434). Added a repeat kwarg to the PastMassBalance in order to loop over a selected period. Added an UncertainMassBalance model which wraps an existing model and adds random uncertainty to it. By Fabien Maussion.
• The DEM sources are now clearly stated in each glacier directory, along with the original data citation (PR441). We encourage to always cite the original data providers. By Fabien Maussion.
• Added some diagnostic tools which make it easier to detect dubious glacier outlines or DEM errors (PR445). This will be used to report to the RGI authors. By Fabien Maussion.

### Bug fixes¶

• Remove dependency to deprecated matplotlib._cntr module (GH418). By Fabien Maussion.
• Fixed a bug in tidewater glaciers terminus position finding, where in some rare cases the percentile threshold was too low (PR444). By Fabien Maussion.
• Fixed a caching bug in the test suite, where some tests used to fail when run for a second time on a modified gdir (PR448). By Fabien Maussion.

### Internals¶

• We now use a dedicated server for input data such as modified RGI files (PR408). By Fabien Maussion.
• Test fix for googlemaps. By Fabien Maussion.
• Added a utility function (idealized_gdir()) useful to dow flowline experiments without have to create a local map (PR413). By Fabien Maussion.

## v1.0 (16 January 2018)¶

This is the first official major release of OGGM. It is concomitant to the submission of a manuscript to Geoscientific Model Development (GMD).

This marks the stabilization of the codebase (hopefully) and implies that future changes will have to be documented carefully to ensure traceability.

New contributors to the project:

• Anouk Vlug (PhD student, University of Bremen), added the CESM climate data tools.
• Anton Butenko (PhD student, University of Bremen), developed the downstream bedshape algorithm
• Beatriz Recinos (PhD student, University of Bremen), participated to the development of the calving parametrization
• Julia Eis (PhD student, University of Bremen), developed the glacier partitioning algorithm
• Schmitty Smith (PhD student, Northand College, Wisconsin US), added optional parameters to the mass-balance models

## v0.1.1 (16 February 2017)¶

Minor release: changes in ITMIX to handle the synthetic glacier cases.

It was tagged only recently for long term documentation purposes and storage on Zenodo.

## v0.1 (29 March 2016)¶

Initial release, used to prepare the data submitted to ITMIX (see here).

This release is the result of several months of development (outside of GitHub for a large part). Several people have contributed to this release:

• Michael Adamer (intern, UIBK), participated to the development of the centerline determination algorithm (2014)
• Kévin Fourteau (intern, UIBK, ENS Cachan), participated to the development of the inversion and the flowline modelling algorithms (2014-2015)
• Alexander H. Jarosch (Associate Professor, University of Iceland), developed the MUSCL-SuperBee model (PR23)
• Johannes Landmann (intern, UIBK), participated to the links between databases project (2015)
• Ben Marzeion (project leader, University of Bremen)
• Fabien Maussion (project leader, UIBK)
• Felix Oesterle (Post-Doc, UIBK), develops OGGR and provided the AWS deployment script (PR25)
• Timo Rothenpieler (programmer, University of Bremen), participated to the OGGM deployment script (e.g. PR34, PR48), and developed OGGM installation tools
• Christian Wild (master student, UIBK), participated to the development of the centerline determination algorithm (2014)