Validation of atmospheric dynamics

Model validation should provide a quantification of the model uncertainties, a reliable review of the forecast results and the possibility for a direct comparison between results of different model simulations.
Atmospheric model validation is presently evolving more and more towards the development and comparison of so-called “process-oriented variables”: deficiencies in reproducing temperature and precipitation fields for example have been identified in terms of model restrictions in reproducing atmospheric circulation variability, leading in particular to substantial differences between models and observation in circulation-climate relationships. Representing the most important processes of atmospheric dynamics (large-scale circulation patterns, planetary and gravity waves) is therefore crucial for climate modelling especially in the range of ten years.
Our proposal (VADY – validation of atmospheric dynamics) to address this issue with respect to model validation includes various approaches focussing on atmospheric wave activity (planetary and gravity waves) in different atmospheric layers and on different spatial scales as well as on circulation types, dynamical modes and teleconnections in the atmosphere. Multivariate statistics as well as recently developed algorithms will be used for the determination and comparison of some few variables mostly easy to calculate in order to allow a relatively quick answer to questions about the representation of atmospheric dynamics in the model.

Goals

DLR
Comparison of MiKlip-model runs with re-analysis data & historical satellite data concerning the following parameters:

• LDAI (Large-scale Dynamical Activity Index) – integrated measure for large-scale atmospheric activity (planetary wave  1 / 2 & tidal activity)
• SDAI (Small-scale Dynamical Activity Index) – integrated measure for gravity wave activity on vertical scales of some kilometres

University of Augsburg

Comparison of MiKlip-model runs with re-analysis data concerning the following objectives based on multi-variate statistics:
Atmospheric circulation types

• Dynamical modes of the atmospheric circulation
• Large-scale teleconnectivity of the atmospheric circulation
• Circulation-climate relationships including near-surface climate
• Circulation analyses for sub-samples of different atmospheric wave activity (in terms of LDAI)