2016 Volume 66 Pages 39-55
Because atmospheric turbulence sometimes causes serious problems for aircraft operations, so it is necessary to detect and bypass turbulence. However, turbulence is difficult to detect by the in situ radiosonde observations or by a wind profiler radar (WPR) network such as WINDAS of Japan Meteorological Agency because of the temporal resolution and available altitude data are inadequate. Therefore, information from the Pilot Weather Report (PIREP) has been almost the only usable turbulence data. To develop the next generation WPR and a better method to detect turbulence, Research Institute for Sustainable Humanosphere (RISH) of Kyoto University, National Institute of Information and Communications Technology (NICT), and Meteorological Research Institute carried out collaborative research from 2011 to 2015. As a part of this research project, experimental observations to compare the prototype of the next generation 1.3GHz WPR (LQ-13) and radiosondes (Vaisala RS92-SGP) were conducted during December, 2012 at NICT (Koganei City, Tokyo). In this study, we compared the turbulent eddy dissipation rates (EDRs) determined with WPR from the Doppler spectrum width data with those determined with radiosondes by using the Thorpe analysis method. The results showed that EDRs determined by both methods were almost consistent. Qualitatively, the EDR increases as the PIREP turbulent intensity increases, but quantitative conclusions could not be reached because there were not enough number of data for moderate or stronger turbulence cases. Because the retrieved EDRs were smaller than International Civil Aviation Organization (ICAO) Annex3 criteria, it will be necessary to assess the EDR criteria for turbulence intensity categories.
