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3 October 200527 th EWGLAM meeting, Ljubljana1 Some developments at ECMWF during 2005 Mariano Hortal ECMWF
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3 October 200527 th EWGLAM meeting, Ljubljana2 Overview New PBL scheme Wavelet J b in 4D-Var T L 799L91 in preoperational mode T L 2047
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3 October 200527 th EWGLAM meeting, Ljubljana3 Is there any skill in cloud forecasts?
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3 October 200527 th EWGLAM meeting, Ljubljana4 ECMWF PBL parameterization (- 2004) (similar at NCAR, NCEP, Arpege, DWD,…) moist mass-flux convection dry K diffusion PBL
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3 October 200527 th EWGLAM meeting, Ljubljana5 PBL cloud unification – an MK approach Martin Köhler, ECMWF key ingredients: moist conserved variables combined Mass-flux/K-diffusion solver cloud variability transition between stratocumulus and shallow convection
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3 October 200527 th EWGLAM meeting, Ljubljana6 A statistical mass flux framework for organized updrafts PDF of {w, q t,q l } Mass flux Top % of updrafts that are explicitly modelled K diffusion {w, q t,q l }
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3 October 200527 th EWGLAM meeting, Ljubljana7 improved marine stratocumulus (MK PBL-old) T511 time=10d n=140 old: CY28R4new MK PBL
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3 October 200527 th EWGLAM meeting, Ljubljana8 Peruvian stratocumulus: model column vs EPIC observations
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3 October 200527 th EWGLAM meeting, Ljubljana9 European Stratus in December 2004
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3 October 200527 th EWGLAM meeting, Ljubljana10 Wavelet Jb Wavelet Jb defines the analysis’ “change-of-variable” and the background cost function as: –Index j denotes “scale” (wavenumber band). –The functions Ψ j are localized spatially, and in wavenumber. –The V j are block-diagonal, with vertical covariance matrix blocks, and one block per gridpoint. Convolution with Ψ j limits the influence of Vj to a band of wavenumbers and to nearby gridpoints. The result is a covariance model that allows both spatial and spectral variation of covariances.
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3 October 200527 th EWGLAM meeting, Ljubljana11 Wavelet J b – 2D Example As an example, we illustrate a 2D covariance model on the sphere: approximately-Gaussian structure functions with spatially-varying length scale (300km – 1300km). The rows of the covariance matrix can be shown by plotting Bx, with x a set of delta functions. For the wavelet Jb covariance model, we have:
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3 October 200527 th EWGLAM meeting, Ljubljana12 Wavelet J b – 2D Example The prescribed length scales are:
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3 October 200527 th EWGLAM meeting, Ljubljana13 Wavelet J b: Where x is a set of delta functions
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3 October 200527 th EWGLAM meeting, Ljubljana14 Wavelet J b Scale with σ j 2 at each gridpoint, and for each scale.
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3 October 200527 th EWGLAM meeting, Ljubljana15 Wavelet J b Convolve again with
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3 October 200527 th EWGLAM meeting, Ljubljana16 Wavelet J b Add together to give:
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3 October 200527 th EWGLAM meeting, Ljubljana17 Wavelet J b Example: Horizontal and vertical Vorticity Correlations. North AmericaEquatorial Pacific
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3 October 200527 th EWGLAM meeting, Ljubljana18 Against analysis Against observations
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3 October 200527 th EWGLAM meeting, Ljubljana19 L91
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3 October 200527 th EWGLAM meeting, Ljubljana20 Higher horizontal and vertical resolution Anomaly correlation of 500hPa height for northern hemisphere T511 L60 T799 L91 Day Mean over 148 cases from 1 August 2004 User Meeting: June 2005
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3 October 200527 th EWGLAM meeting, Ljubljana21 Higher horizontal and vertical resolution Anomaly correlation of 500hPa height for Europe T511 L60 T799 L91 Day Mean over 148 cases from 1 August 2004 User Meeting: June 2005
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3 October 200527 th EWGLAM meeting, Ljubljana22 Higher horizontal and vertical resolution Anomaly correlation of 500hPa height for southern hemisphere T511 L60 T799 L91 Day Mean over 197 00UTC cases from 1 January 2005
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3 October 200527 th EWGLAM meeting, Ljubljana23 Statistical significance t test, 500hPa root-mean-square error Day 3Day 5Day 7 N Hem0.2%-- S Hem0.1% Europe5% - Green denotes T799L91 better
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3 October 200527 th EWGLAM meeting, Ljubljana24 RMS tropical temperature errors against radiosondes T511 L60 T799 L91 Mean over 197 00UTC cases from 1 January 2005 500hPa 300hPa 100hPa 50hPa Day
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3 October 200527 th EWGLAM meeting, Ljubljana25 Fit to TEMP observations
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3 October 200527 th EWGLAM meeting, Ljubljana26 Forecasts of Katrina D+108h T511 L60 T799 L91
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3 October 200527 th EWGLAM meeting, Ljubljana27 T511 Hurricane Katrina at T511 and T799 T799 Observed low of 902hPa 921 959
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3 October 200527 th EWGLAM meeting, Ljubljana28 IFS Model Run-times on IBM p690+ Resolution & time-step CPUsWall time for 1- day forecast (minutes) Gflops on IBM p690+ % of Peak* T511 L60 900 sec 128 7 81 8.4 T799 L91 720 sec 256 16 177 9.1 T1279 L60 450 sec 512 23 354 9.1 T2047 L60 300 sec 768 68 537 9.2 * Peak is 7.6 Gflops per PE for IBM p690+
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3 October 200527 th EWGLAM meeting, Ljubljana29 Profile for T2047 on IBM p690+ (768 CPUs) Legendre Transforms ~17% of total cost of model Physics ~36% of total cost
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3 October 200527 th EWGLAM meeting, Ljubljana30 Comparison of profiles at different resolutions
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3 October 200527 th EWGLAM meeting, Ljubljana31 40km 25km 10km Spectra of total KE log 10 k k -3 k -5/3 Power spectra of total kinetic energy at T511, T799 & T2047
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3 October 200527 th EWGLAM meeting, Ljubljana32 Case-study of an event of heavy rainfall (orographically induced) with severe flooding in the South of France in September 2002 (Observed rainfall in excess of 500mm/24h): Comparison of precipitation forecast (24-48h range) at T511, T799, T1279 and T2047
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3 October 200527 th EWGLAM meeting, Ljubljana33 10m-Wind for the South of France on 9 September 2002 at 0UTC 10m-wind from T2047 36h-forecast
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3 October 200527 th EWGLAM meeting, Ljubljana34 Total precipitation accumulated over 24-48h FC-range T511 T1279 T799 T2047 max ~ 78mm max ~ 150mm max ~ 197mm max ~ 321mm
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3 October 200527 th EWGLAM meeting, Ljubljana35 Rainfall Verification over South of France for T2047 24-48h forecast
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3 October 200527 th EWGLAM meeting, Ljubljana36 Precipitation skill as a function of model resolution T2047 T1279 T799 T511 (ops) ACC Z500 ACC PT2 Station location TP 2000/07/18 – 2005/02/15 Extreme observed rainfall 2002/09/08 ResolutionEuropeFrance T20470.560.61 T12790.520.60 T7990.450.55 T511 (op)0.380.41 90% confidence intervals indicated
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3 October 200527 th EWGLAM meeting, Ljubljana37 Thank you very much for your attention
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