Chapter 3: Programme Strategy

• Phase I of the programme is dedicated to modelling activities, theoretical studies, improvement of existing Alpine climatologies, and to the preparation of the field phase. A distinctive feature of the programme is that a number of these activities will continue throughout its duration.
• Phase II is the field phase with a duration of 13 months, and is also referred to as General Observing Period (GOP). For most of its duration, it will be primarily based on operational observing systems, but during a 3-month Special Observing Period (SOP), dedicated observing systems such as research aircraft and temporarily installed observational platforms will be deployed, and activated during a number of Intensive Observing Periods (IOPs).
• Phase III of the programme is dedicated to the analysis of the field phase results and further modelling studies.

For Phase I four different work areas are described in some detail. The goals for the numerical experimentation during Phase I of MAP are to systematically evaluate the predictive skill and the limitations of NWP models in simulating heavy precipitation events and orographically-induced flow systems in the Alpine area; to improve mesoscale data assimilation procedures, with particular emphasis on humidity and water variables; and to aid in the design of the field experiment, especially in defining specific areas for high-density observational networks. In addition, a climatological survey is needed for the detailed planning of the field phase. The survey will aid the definition of location, time and duration of the Special Observing Period. Furthermore new observing systems such as wind profilers and other remote sensing systems should be tested during phase 1, and contact should be established with a dedicated group of operational forecasters of all Alpine countries with the aim of forming a group of specialists on MAP-related subjects. This will serve to pinpoint the key forecasting issues, facilitate the introduction of better forecasting methods, and help establish decision trees for the forecasting issues of the field phase.

For Phase II specific information is given in three subsections, namely the Field Experiment: Time, Duration and Location , the Observational Strategy and Observational Requirements. The MAP field experiment will take place during a 13-month period, (the so-called General Observing Period, GOP) during which the normal station network will be upgraded and mesoscale forecasting efforts will be intensified. Within the GOP, a 3-month period will be designated as a Special Observing Period (SOP) for which the time and space resolution of the routine observational networks will be enhanced. At present, the 3-month period lasting from mid August to mid November appears climatologically to be the most suitable for measurements documenting the phenomena related to the primary objectives of the programme, i.e., convection, gravity waves and Foehn. Within the SOP, a number of Intensive Observing Periods IOPs, say 10 to 15 each of 1 to 3 days duration, will be defined. During these IOPs, whose selection depend on the actual meteorological situation, all available measuring platforms, including research aircraft will be deployed.