Conceptual Model Approach
The physical-meteorological evaluation of a combination of such different data as descriptions of image structures, irregular distributed point measurements from synoptic observations and numerical parameter fields on a defined grid is not a simple task. There is, however, one tool already widely used in synoptic research and operations - the Conceptual Model Approach.
Definition of conceptual models
A definition of conceptual models as well as examples showing the usefulness have been derived among European countries in the frame of the COST 78 action (Development of forecasting techniques):
A conceptual model describes essential features of a meteorological phenomenon and identifies the principal processes taking place.
A complete conceptual model provides a:
- Definition of the phenomenon in terms of features recognizable by observations, analysis or validated simulations;
- Description of its life cycle in terms of appearance, size, intensity and accompanying weather;
- Statement of the controlling physical processes which enables the understanding of the factors that determine the mode and rate of evolution of the phenomenon;
- Specification of the key meteorological fields demonstrating the main processes;
- Guidance for predicted meteorological conditions or situations using the diagnostic and prognostic fields that best discriminate between development or non-development; guidance for predicting displacement and evolution.
Additional Explanatory Statements
There are some additional, explanatory statements to this definition about satellite images and conceptual models:
- The structure, organisation and development of clouds, cloud systems and WV structures can be observed in satellite images.
- These features are manifestations of the physical and dynamical processes in the troposphere that have taken place, are currently taking place or will take place in the immediate future.
- These processes are also represented by relevant quantitative parameters, their values and configurations computed in numerical models
Many instances of the same weather system have to be investigated to develop a specific CM. In SatManu about 100 cases have been diagnosed for frequent weather systems, while for rarer cases the number is about 30. Those features and configurations that are common to all cases and can be explained by the relevant physical-meteorological processes are described in a single SatManu chapter on CM structure and presentation (link to chapter "Structure and Presentation of CMs in SatManu").
Conceptual models provide the meteorologist with:
- help in understanding and diagnosing phenomena
- a synthesis of all available information
- a 4-dimensional "mental picture"
- the basis for isolating weather processes
- the basis for extracting the main signals from complex patterns
- tools for support of the diagnosis of numerical models
- a supplement to numerical models for the nowcast time scale
- tools for identifying shortcomings in the numerical forecast
- tools for modification of numerical products
- a fast forecast method
- an independent forecast method
- a forecast method particularly for hazardous weather
- the possibility of filling in gaps in the data