Land surface assimilation

This lecture note provides a review of techniques recently developed for initialising the prognostic variables of land surface parametrizations in numerical weather prediction models. The importance of soil moisture initialisation is emphasized since the evolution of the boundary layer is very sensitive to its specification and the associated time scales are much longer than those of medium range forecasts. The analysis of snow mass is also described, using the ECMWF method as an illustrative example. Different methods and data available for the initialisation of other slowly varying components at the surface, such as soil temperature, vegetation fraction, leaf area index and albedo, are described at the end.

Contents

1. Introduction
2. Design of land surface parametrizations
3. Introduction to land surface assimilation
4. Simple land surface initialisation methods
5. Soil moisture initialisation using SYNOP observations
6. Other techniques to initial soil moisture
7. Initialisation of other land surface quantities
8. Conclusions
9. References