WMO-No. 1038
ISBN 978-92-63-11038-1
Publication year 2009
The 3rd edition is now available. This project was coordinated by Olivier Liechti.
WMO-No. 1038
ISBN 978-92-63-11038-1
Publication year 2009
Price 25.00 CHF
It can ordered through the WMO publication catalog
In Chapter 1, the three main types of lift enabling soaring flight - convection, ridge and wave lift - were described. The physical basis for each was given, providing the meteorologist with the understanding to produce meaningful soaring forecasts. Pilot stories describing flights in the three types of lift illustrated the intimate connection, in the cockpit, between theory and practice.
The technical description of gliding and soaring flight in Chapter 2 illustrated the impact of weather on feasibility, timing, range of operations and safety. The connection between glider aerodynamics and meteorology was detailed and used to explain the remarkable flight speeds gliders achieve.
Chapter 3 contained a summary of the essential basics of numerical weather predictions, which are the foundations of current meteorological practice. Explanations of data input, parameterization schemes, scale separations, model outputs and interpretation and verification of forecasts provided insight regarding model successes and limitations. Soaring forecasts for convection, ridge and wave lift based on numerical models were shown to have significant spatial and temporal detail.
In Chapter 4, the weather analyses and forecasts necessary for supporting soaring flights were identified. The role and benefits of the team meteorologist were described. An NWP-based flight planning tool was illustrated; a glider was essentially "flown" through the prediction to estimate the feasibility of a task.
The GPS flight data recorded aboard most sailplanes were described in Chapter 5. Validation of forecasts using these data supports the underlying NWP forecasts, thus demonstrating the usefulness of the glider as an atmospheric probe. New relationships involving climb rate versus convective boundary layer depth were developed.
The major advance in weather forecasting for soaring flight has been the prediction by numerical models of climb rates and altitudes in convection. NWP-based flight planning also would benefit from such predictions for ridge and wave lift. A particular challenge with these types of lift is their spatial alignment. Current studies address these issues.
In spite of this progress, our knowledge concerning lift is incomplete. Over the past 80 or 90 years, soaring pilots have identified lift sources that can be categorized as convection, convergence, ridge, wave or some combination of these. It is not uncommon, however, for the soaring pilot to report lift with characteristics, or in a background environment, that do not fit our current conceptual models. It is possible that in the future, reports from soaring flights, combined with atmospheric research, will identify other, as yet unknown, lift sources.