Presentation to the Inter-Agency Committee for Hydrological Uses of Radar Data, University of Bristol, 5 August 2004

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Presentation to the Inter-Agency Committee for
Hydrological Uses of Radar Data, University of
Bristol, 5 August 2004

• C.G.Collier
• University of Salford

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(No Transcript)
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Combining and comparing rainfall observing
systems in hydrological modelling of a rural
catchment

• G.L.Robbins1, M.Grum2 and C.G.Collier1
• 1 Univ. Salford 2 PH-Consult, Denmark

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Rainfall measurements relative strengths.
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A simple model which, one step ahead, predicts
the rainfall intensity to be a weighting of its
immediate own current value with its neighbours
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Schematic of a simple catchment model
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Croal catchment and hydrometeorological network
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Rainfall, observed river flow and forecast
hydrographs after various time steps
13 September 2001
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Error in peak flow magnitude and time of
occurrence of peak flow
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Assimilation of Doppler radial winds into a high
resolution NWP model

• F.A.Rihan1, C.G.Collier1, S.P.Ballard2 and
  S.J.Swarbrick2
• 1 University of Salford 2 JCMM, Met Office

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Impact of a strong velocity gradient across the
pulse volume and instrumental noise on the
Doppler wind spectrum
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Schematic representation showing a convergence
line moving from left to right. Gaussian noise
represents the measurement error
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Chilbolton (300m 4 km res.) and 1 km NWP model
radial winds 1 July 2003. Model at two elevations
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Model radial winds at 4 km resoln.
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Next steps

• Met Office to complete 3D-var (later 4D-Var)
  assimilation system
• Observing System Simulation Experiments (OSSEs)