7th Framework Programme
     Environmental Flight Planning / Meteorological Weather Situations     03 May 2010

Meteorological weather situations

Within REACT4C a set of representative meteorological situations will be derived which will be used in subsequent work packages (WPs) as input for flight planning and assessment of the climate impact of different choices of flight routes.

The underlying concept will be to identify a number of distinct weather situations for which standard flight planning tools (which generally aim to minimise fuel use) generate distinct choices of routes. For these distinct weather situations, climate cost functions (WP2) are diagnosed and flight routings will be identified, that minimize fuel consumption, emissions and environmental impact, respectively (environmental flight planning, WP3).

Characterization of distinct weather situations

Operationally-derived optimal flight routes, provided to national air traffic services, will be used in conjunction with meteorological analyses from weather forecast centres, to identify distinct meteorological situations which lead to different recommended routes - these will include cases for which the recommended routes are close to great circle routes, and those that deviate most markedly from great circle routes, either to the north or south. For example, within the North Atlantic, routing will depend on the presence of cyclonic and anticyclonic conditions and the position and strength of the jet stream, and the routing will be different for eastbound and westbound flights. It is important that the idenfified weather situations are not extreme, but rather cases that occur with sufficient frequency to make an analysis of different routing options (accounting for more than just fuel use) worthwhile.

Use of GCM for calculation of cost functions

The data for cost function calculations will be generated by a General Circulation Model (GCM), instead of from meteorological analyses or re-analyses in order to be able to easily repeat identical CCM simulations including contrails (potentially plus contrail cirrus), aerosol effects and modifications of chemical composition. Another reason for using CCM data is that radiative forcing (RF) calculations are possible online. Hence, an important task will be to identify weather situations within the GCM that correspond closely to the distinct weather situations derived from the reanalysis data.