3 October th EWGLAM meeting, Ljubljana1 Some developments at ECMWF during 2005 Mariano Hortal ECMWF
3 October th EWGLAM meeting, Ljubljana2 Overview New PBL scheme Wavelet J b in 4D-Var T L 799L91 in preoperational mode T L 2047
3 October th EWGLAM meeting, Ljubljana3 Is there any skill in cloud forecasts?
3 October th EWGLAM meeting, Ljubljana4 ECMWF PBL parameterization (- 2004) (similar at NCAR, NCEP, Arpege, DWD,…) moist mass-flux convection dry K diffusion PBL
3 October 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
3 October 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 }
3 October th EWGLAM meeting, Ljubljana7 improved marine stratocumulus (MK PBL-old) T511 time=10d n=140 old: CY28R4new MK PBL
3 October th EWGLAM meeting, Ljubljana8 Peruvian stratocumulus: model column vs EPIC observations
3 October th EWGLAM meeting, Ljubljana9 European Stratus in December 2004
3 October 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.
3 October 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:
3 October th EWGLAM meeting, Ljubljana12 Wavelet J b – 2D Example The prescribed length scales are:
3 October th EWGLAM meeting, Ljubljana13 Wavelet J b: Where x is a set of delta functions
3 October th EWGLAM meeting, Ljubljana14 Wavelet J b Scale with σ j 2 at each gridpoint, and for each scale.
3 October th EWGLAM meeting, Ljubljana15 Wavelet J b Convolve again with
3 October th EWGLAM meeting, Ljubljana16 Wavelet J b Add together to give:
3 October th EWGLAM meeting, Ljubljana17 Wavelet J b Example: Horizontal and vertical Vorticity Correlations. North AmericaEquatorial Pacific
3 October th EWGLAM meeting, Ljubljana18 Against analysis Against observations
3 October th EWGLAM meeting, Ljubljana19 L91
3 October 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
3 October 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
3 October th EWGLAM meeting, Ljubljana22 Higher horizontal and vertical resolution Anomaly correlation of 500hPa height for southern hemisphere T511 L60 T799 L91 Day Mean over UTC cases from 1 January 2005
3 October 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
3 October th EWGLAM meeting, Ljubljana24 RMS tropical temperature errors against radiosondes T511 L60 T799 L91 Mean over UTC cases from 1 January hPa 300hPa 100hPa 50hPa Day
3 October th EWGLAM meeting, Ljubljana25 Fit to TEMP observations
3 October th EWGLAM meeting, Ljubljana26 Forecasts of Katrina D+108h T511 L60 T799 L91
3 October th EWGLAM meeting, Ljubljana27 T511 Hurricane Katrina at T511 and T799 T799 Observed low of 902hPa
3 October 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 L sec T799 L sec T1279 L sec T2047 L sec * Peak is 7.6 Gflops per PE for IBM p690+
3 October 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
3 October th EWGLAM meeting, Ljubljana30 Comparison of profiles at different resolutions
3 October 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
3 October 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
3 October th EWGLAM meeting, Ljubljana33 10m-Wind for the South of France on 9 September 2002 at 0UTC 10m-wind from T h-forecast
3 October th EWGLAM meeting, Ljubljana34 Total precipitation accumulated over 24-48h FC-range T511 T1279 T799 T2047 max ~ 78mm max ~ 150mm max ~ 197mm max ~ 321mm
3 October th EWGLAM meeting, Ljubljana35 Rainfall Verification over South of France for T h forecast
3 October 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 T T T T511 (op) % confidence intervals indicated
3 October th EWGLAM meeting, Ljubljana37 Thank you very much for your attention