• DOI:10.1127/0941-2948/2007/0244
• Corpus ID: 123055587

Further investigation on adjoint sensitivity of surface precipitation to initial conditions

@article{Mahfouf2007FurtherIO,
  title={Further investigation on adjoint sensitivity of surface precipitation to initial conditions},
  author={Jean-François Mahfouf and Bernard Bilodeau},
  journal={Meteorologische Zeitschrift},
  year={2007},
  volume={16},
  pages={595-605}
}

• J. Mahfouf, B. Bilodeau
• Published 1 August 2007
• Environmental Science
• Meteorologische Zeitschrift

The adjoint version of the Canadian global numerical weather prediction model including moist physical parameterizations is used to investigate the sensitivity of surface precipitation to initial conditions. This study complements results shown in a previous paper by MAHFOUF and BILODEAU (2007). The importance of the dynamics is examined by considering the sensitivity in terms of streamfunction and velocity potential. The contribution of the divergence field to the sensitivity produced by the dynamics dominates at the beginning of the adjoint integration. The adjoint sensitivity of surface precipitation is compared to the sensitivity of a diagnostic function defined by the integrated water vapour in rainy areas. This comparison provides useful information on the relevance of the "1D+4D-Var" methodology for the variational assimilation of rainfall observations. Finally, a set of 8 additional case studies is examined in order to increase the confidence in our previous conclusions obtained for two meteorological systems. The validity of the tangent-linear approximation is case dependent but in average is better for mid-latitude than for tropical regions. The dominance of the initial temperature field on surface precipitation is confirmed for all systems.