OGGM offers an option for reconstructing the recent past of a glacier by using a so called “dynamic spinup”, during which the state of the glacier in the past is estimated by an iterative approach. MAny possible past (1979) states are tested, and the first one which leads to a correct representation of today’s glacier geometry after a forward run from 1979 to the RGI date. For the match criterion, you can choose if you want to match area OR volume at the RGI date.
Furthermore, this dynamic spinup can be combined with a dynamic calibration of the temperature sensitivity \(d_f\). This calibration attempts to also calibrate \(d_f\) to match geodetic MB data as described in Monthly temperature index model calibrated on geodetic MB data, but taking the dynamically changing glacier geometry into account.
Both functions, the dynamic spinup and the dynamic \(d_f\) calibration, are combined in one consistent model calibration and initialisation workflow. This workflow also includes the glacier bed inversion for consistency. See the following schematic for a description of the standard steps in the spinup.
We offer pre-processed directories including a dynamic spinup run. You can check out this 10 minute tutorial for a short introduction to the spinup functions and how to use the pre-processed directories.
If you are looking for an in-depth explanation of the dynamic functions you should check out this advanced tutorial.