Open Access3D-Var Assimilation of Insect-Derived Doppler Radar Radial Winds in Convective Cases Using a High-Resolution Model
Author(s) -
Susan Rennie,
Sarah L. Dance,
Anthony J. Illingworth,
Sue Ballard,
David Simonin
Publication year - 2011
Publication title -
monthly weather review
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.862
H-Index - 179
eISSN - 1520-0493
pISSN - 0027-0644
DOI - 10.1175/2010mwr3482.1
Subject(s) - clutter , radar , environmental science , data assimilation , meteorology , numerical weather prediction , doppler radar , convection , doppler effect , weather radar , high resolution , remote sensing , geology , computer science , physics , telecommunications , astronomy
The assimilation of Doppler radar radial winds for high-resolution NWP may improve short-term forecasts of convective weather. Using insects as the radar target, it is possible to provide wind observations during convective development. This study aims to explore the potential of these new observations, with three case studies. Radial winds from insects detected by four operational weather radars were assimilated using three-dimensional variational data assimilation (3D-Var) into a 1.5-km resolution version of the Met Office Unified Model, using a southern U.K. domain and no convective parameterization. The effect on the analyzed wind was small, with changes in direction and speed up to 45° and 2 m s−1, respectively. The forecast precipitation was perturbed in space and time but not substantially modified. Radial wind observations from insects show the potential to provide small corrections to the location and timing of showers, but not to completely relocate convergence lines. Overall, quantitative analysis indicated the observation impact in the three case studies was small and neutral. However, the small sample size and possible ground clutter contamination issues preclude unequivocal impact estimation. The study shows the potential positive impact of insect winds; future operational systems using dual-polarization radars that are better able to discriminate between insects and clutter returns should provide a much greater impact on forecasts.