run_mb_calibration.rst

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5. Run the mass-balance calibration

Sometimes you will need to do the mass-balance calibration yourself. For example if you use alternate climate data, or if you change the global parameters of the model (such as precipitation scaling factor or melting threshold, for example). Here we show how to run the calibration for all available reference glaciers. We also use this example to illustrate how to do a "full run", i.e. without relying on preprodir.

The output of this script is the ref_tstars.csv file, which is found in the working directory. The ref_tstars.csv file can then be used for further runs, simply by copying it in the corresponding working directory before the run.

Script

_code/run_reference_mb_glaciers.py

Cross-validation

The results of the cross-validation are found in the crossval_tstars.csv file. Let's replicate Figure 3 in Marzeion et al., (2012) :

_code/mb_crossval.py

This should generate an output similar to:

Median bias: 18.78
Mean bias: 15.34
RMS: 518.83
Sigma bias: 0.87

Error (bias) distribution of the mass-balance computed with a leave-one-out cross-validation.