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Module smb_oggm

Module smb_oggm implements the monthly temperature index model calibrated on geodetic mass balance (MB) data (Hugonnet et al., 2021)1 by OGGM. The yearly surface mass balance is computed with:

\[SMB = \frac{\rho_w}{\rho_i} \sum_{i=1}^{12} \left( P_i^{sol} - d_f \max \{ T_i - T_{melt}, 0 \} \right),\]

where \(P_i^{sol}\) is the monthly solid precipitation, \(T_i\) is the monthly temperature, and \(T_{melt}\) is the air temperature above which ice melt is assumed to occur (parameter temp_melt). The parameter \(d_f\) is the melt factor (parameter melt_f), and \(\frac{\rho_w}{\rho_i}\) is the ratio of water to ice density. Solid precipitation \(P_i^{sol}\) is computed from precipitation and temperature such that it equals precipitation when the temperature is lower than a certain threshold (parameter temp_all_solid), zero above another threshold (parameter temp_all_liq), with a linear transition between the two. Module oggm_shop provides all calibrated parameters (Maussion et al., 2019)2.

Contributors: Guillaume Jouvet, Fabien Maussion.

Parameters

Default configuration file (smb_oggm.yaml): 

smb_oggm:
  update_freq: 1.0
  ice_density: 910.0
  wat_density: 1000.0
  melt_enhancer: 1.0

Description of the parameters:

Name Description Default value Units
update_freq Update the mass balance each X years. 1.0 y
ice_density Density of ice for conversion of SMB into ice equivalent. 910.0 kg m\( ^{-3} \)
wat_density Density of water. 1000.0 kg m\( ^{-3} \)
melt_enhancer Melt enhancer factor. 1.0 —

  1. Hugonnet, R., McNabb, R., Berthier, E., Menounos, B., Nuth, C., Girod, L., Farinotti, D., Huss, M., Dussaillant, I., Brun, F., & Kääb, A. (2021). Accelerated global glacier mass loss in the early twenty-first century. Nature, 592(7856), 726--731. https://doi.org/10.1038/s41586-021-03436-z ↩

  2. Maussion, F., Butenko, A., Champollion, N., Dusch, M., Eis, J., Fourteau, K., Gregor, P., Jarosch, A. H., Landmann, J., Oesterle, F., Recinos, B., Rothenpieler, T., Vlug, A., Wild, C. T., & Marzeion, B. (2019). The open global glacier model (OGGM) v1.1. Geoscientific Model Development, 12(3), 909--931. https://doi.org/10.5194/gmd-12-909-2019 ↩