Thursday, 20 June 2002
Comparison of MAP-sop observations with model analysis and forecasts of gravity wave breaking
High resolution models available during the MAP Special Observing Period produced analysis and forecasting of Gravity Wave Breaking' index Ri (Richardson Number), while the enhanced upper air network provided observational data with high spatial and temporal frequency.
The observational data set has been used for detailed, single profile analysis as well as for a spatial analysis based on radio sounding derived quantities. An interpolation method has been developed which, making use of a maximum of 16 Gauss functions, allows an analytical profile interpolation and an accurate calculation of Ri and other indexes on several tropo- and stratospheric layers above almost all the Map radio sounding stations .
A mesoscale analysis of the upper atmospheric temperature field also allowed using the same method on vertical profiler's wind data, and increased the spatial resolution of the horizontal analysis of the Richardson number.
Finally, a direct comparison of single profile and horizontal analysis derived values with the available model analysis and forecast shows the limited ability even of HR LAM to predict location and timing (and even the simple occurrence) of GWB. On the other hand, the method provides indications for an operational use of real time observations at the advantages of aviation safety.
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