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CarpeDiem Project, Bologna 1/12/2004. WP-6 Anomalous Propagation. CarpeDiem Project, Bologna 1/12/2004. RADAR OBSERVATIONS & ANOMALOUS PROPAGATION. PBEZTPPI06_VRG-112. PBEZTPPI06_VRG-043. CarpeDiem Project, Bologna 1/12/2004. World-wide VRG 1km, August (ITU, 1997).
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CarpeDiem Project, Bologna 1/12/2004 WP-6 Anomalous Propagation
CarpeDiem Project, Bologna 1/12/2004 RADAR OBSERVATIONS & ANOMALOUS PROPAGATION PBEZTPPI06_VRG-112 PBEZTPPI06_VRG-043
CarpeDiem Project, Bologna 1/12/2004 World-wide VRG 1km, August (ITU, 1997)
CarpeDiem Project, Bologna 1/12/2004 BARCELONA RPC COMPUTED FROM RADIOSONDE OBSERVATIONS (RAOB): - 00 Z & 12Z (41.38ºN, 2.12ºE) - VAISALA RS-80 SONDES - 10 S SAMPLING - 1997 TO 2002 (2485 OBS) RAOB DATA READ RAOB QUALITY CONTROL 85% VALID RAOB PROFILES (Ns, VRG,..) - POSTPROCESSING - STATISTICAL ANALYSIS - COMPARISON VRG vs Ns PROCESS RPC RPC REPORT WRITE RPC REPORT RAOB PROCESSING BLOCK DIAGRAM Weather Radar anomalous propagation (AP)
CarpeDiem Project, Bologna 1/12/2004 YEARLY DIURNAL RANGE SUMMER DIURNAL RANGE NEXRAD beam blockage correction sensitivity analysis (Bech et al. JTECH 2003) ±0.05º ±0.10º ±0.05º Radar beam blockage and anaprop in complex terrain
CarpeDiem Project, Bologna 1/12/2004 VRG = N / z ITU (1997), Steiner and Smith (2002) ID = 78 z - M Johnson et al. (1999) Different MASS model domains. November 2002 to February 2003 (183 cases) Forecasts of refractivity profiles based on 12 & 24 H MASS model output 00 & 12 Z RAOB Modified refractivity forecast and observed profile. Use of NWP forecasts & RAOB to monitor AP
CarpeDiem Project, Bologna 1/12/2004 Use of NWP forecasts & RAOB to monitor AP
CarpeDiem Project, Bologna 1/12/2004 Ground clutter and beam blocking – representativeness of different datasets to reproduce the beam path 9 July 2003, 00:00 UTC datasets: RAW RADIOSOUND. DATA TEMP DATA LOKAL MODEL DATA (LM) LOWER LIMIT OF 3 dB - BEAM
SUMMARY (1/2) • Beam blockage vs VRG variability simulated with an interception function. • Blockage corrections were generally robust. • VRG induced errors comparable to antenna alignment errors. • Clutter echoes may be cleaned BUT echo heights may still be affected for some applications requiring precise height measurements (VAD assimilation,..).
SUMMARY (2/2) • Original model forecasts were biased towards subrefraction. • Model output anticipated correctly average conditions & tendency. • New modified forecasts improved significantly verification scores. • In some cases RAOB persistency yielded better results than NWP forecasts.