AMS Conference January 2010 Atlanta, GA NCAR/RAL - National Security Applications Program Evaluation of Large Eddy Numerical Simulations (LES) with Observations from FUsing Sensor Information from Observing Networks (FUSION) Field Trial 2007 (FFT-07) Andrzej A. Wyszogrodzki Jeffrey Weil, George Bieberbach, Paul E. Bieringer National Center for Atmospheric Research, Boulder, CO Nathan Platt, and Leo H. Jones Institute for Defense Analysis, Alexandria, VA

AMS Conference January 2010 Atlanta, GA NCAR/RAL - National Security Applications Program Virtual THreat Response Emulation and Analysis Testbed (VTHREAT) High fidelity models to create realistic virtual environment and synthetic observations Atmospheric Models (EULAG/WRF) Atmospheric Models (EULAG/WRF) Transport and Dispersion Models (EULAG/LPDM /SCIPUFF) Transport and Dispersion Models (EULAG/LPDM /SCIPUFF) Models and Analysis Systems Models and Analysis Systems Generation of Synthetic Environment Simulated Sensor Measurements Applications That Utilize Observations Evaluation of atmospheric and transport and dispersion (T&D) model performance EULAG – multiscale geophysical fluid flow model nonhydrostatic, anelastic approximation, LES, passive scalar T&D Evaluate system ability to simulate physically realistic atmospheric environment and T&D in extreme conditions Test accuracy of variable in time mean conditions turbulent fluctuations, and contaminant concentrations CURRENT TASKS

AMS Conference January 2010 Atlanta, GA NCAR/RAL - National Security Applications Program Fusion Field Trials 2007 (FFT07) PRESELECTED TRIALS: TRIAL 16 – plume/daytime TRIAL 54 – plume/daytime TRIAL 30 – plume/nighttime TRIAL 36 – puffs/daytime TRIAL 71 – puffs/nighttime Continuous propylene release Locations of Digipids (blue) and Uvics (yellow) FFT07 at Dugway Prowing Ground (UT)

AMS Conference January 2010 Atlanta, GA NCAR/RAL - National Security Applications Program EULAG initialization and BC for Trail 54 morning transitional effects (8:00 – 8:45 Local Daylight Saving Time) Surface heat fluxes: - turbulence tower data - SAMS measurements of incoming solar radiation: HF=Cf*Sol, where the coefficient Cf= determined from the local PBL height model. Potential temperature profile: - SLC (or LKN) profile at 12 UTC - θ=303.4 K at surface, - θ gradient: 20 K/km below 400m, - θ gradient: 1.5 K/km above 400m Thermal conditions Composite wind conditions Variable in time wind: 2m - domain averaged 40 PWIDS - wind speed 3 m/s, - wind direction ~ deg 4-32m – averaged 3 towers m - 15 minute averaged Sodar data 14:15 and 14:45 UTC above 150m – interpolation to SLC/LKN stations WIND DIRECTION WIND SPEED WIND DIR

AMS Conference January 2010 Atlanta, GA NCAR/RAL - National Security Applications Program Sodar data between 14:15-14:45 UTC Nudging – key component to capture near surface transitional effects Domain size 1.6 x 2.4 x 0.5 km Periodic BC Homogeneous surface No information about thermal structure of BL at DPG site Parameters used to estimate nudging time scale: w*= m/s (H flux = Km/s) Zn=50m – max wind variability below Zn Tn=60 sec Time evolution of model winds Nudging Nudging time scale Tn=Zn/w* =50-70 sec WIND SPEED WIND DIR

AMS Conference January 2010 Atlanta, GA NCAR/RAL - National Security Applications Program Fusion Field Trials 2007 (FFT07) Trial 54 FFT07: 40 PWIDS [u, v, w measurements at 10 seconds] PWIDS = Portable Weather Information Display System EULAG: ensemble of 20 grids (40 sensor locations per grid, 800 sensors total) in the same configuration as FFT07 PWIDS, but at different physical locations FFT07 at Dugway Prowing Ground (UT) Locations of Pwids

AMS Conference January 2010 Atlanta, GA NCAR/RAL - National Security Applications Program How much the observed variability is influenced by the inhomogeneity of the SL? mean wind: required for capture plume meandering wind fluctuations: required for plume dispersion Evaluation of atmospheric model performance wind mean components and fluctuations EULAG realizations (red) ensemble averaged (blue) FFT07 sensor averaged (black) FFT07 realizations (red) sensor averaged (black) U (m/s) DIR (deg) T (C) Time (UTC) EULAG: 10m resolution

AMS Conference January 2010 Atlanta, GA NCAR/RAL - National Security Applications Program Evaluation of atmospheric model performance possible physical sources of error in observations Larger scale effects: –Thermal mountain/valley flow structure (e.g. drainage flows) –Mesoscale winds interacting with nearby mountains Effects not accounted in current idealistic FFT07 simulations Surface heterogeneity: –Roughness variability due to vegetation –Small scale topographical features (e.g. gentle terrain slopes, dry forks) washes Mountain range ~2km

AMS Conference January 2010 Atlanta, GA NCAR/RAL - National Security Applications Program REAL SURFACE: inhomogeneous MODEL SURFACE: homogeneous Effects not accounted in current idealistic FFT07 simulations washes Mountain range ~2km To compare fluctuations (turbulence) from model and field sensors we must account for surface inhomogeneity and their effects on the sensor measurements Bias due to inhomogeneity = time - x Evaluation of atmospheric model performance possible physical sources of error in observations

AMS Conference January 2010 Atlanta, GA NCAR/RAL - National Security Applications Program Atmospheric conditions evaluation observational bias at different PWID locations Red = model Blue = biased observations V (m/s) u (m/s)

AMS Conference January 2010 Atlanta, GA NCAR/RAL - National Security Applications Program Atmospheric conditions evaluation removing bias from the observations Red = model Black = unbiased observations u (m/s) V (m/s)

AMS Conference January 2010 Atlanta, GA NCAR/RAL - National Security Applications Program Red = model Blue = biased observations Atmospheric conditions evaluation observational bias at all PWID locations and times

AMS Conference January 2010 Atlanta, GA NCAR/RAL - National Security Applications Program Red = model Black = unbiased observations Atmospheric conditions evaluation removing bias from All observations

AMS Conference January 2010 Atlanta, GA NCAR/RAL - National Security Applications Program T&D model evaluation EULAG start time at 13:35 UTC (∆= 10m, dt=0.25 sec) 13:55 UTC (∆= 5 m, dt=0.2 sec) 14:05 UTC (∆=2.5 m, dt=0.125 sec) - Length of the simulation min Trial 54, Continuous Release, 1 Source (Propylene) Ensemble of 20 grids at different spatial locations Shifted in X and Y directions Point to point comparison between model and field sensor locations EULAG realization (red) FFT07 sensor measurement (blue)

AMS Conference January 2010 Atlanta, GA NCAR/RAL - National Security Applications Program T&D model evaluation for Trail 54, near source time series (Digipid 78) cc cc cc 15min D10m D 5m D2.5m m 2.5m 10m ~150m from source shown by arrow Ratio: cc_fft07 / cc_model cc – peak, concentration 1s averaged 15min – 15 minute time integral Tume [UTC]

AMS Conference January 2010 Atlanta, GA NCAR/RAL - National Security Applications Program 10m 5m 2.5m ~400m from source shown by arrow Ratio: cc_fft07 / cc_model cc – peak, concentration 1s averaged 15min – 15 minute time integral cc cc cc 15min D10m D 5m D2.5m T&D model evaluation for Trail 54, time series at larger distance (Digipid 26) Tume [UTC]

AMS Conference January 2010 Atlanta, GA NCAR/RAL - National Security Applications Program T&D model evaluation SCIPUFF LES – 10m LES – 5m SCIPUFF concentrations [ppm] EULAG concentrations [ppm] EULAG concentrations [ppm] FFT07 concentrations [ppm] EULAG concentrations [ppm] LES – 2.5m

AMS Conference January 2010 Atlanta, GA NCAR/RAL - National Security Applications Program Progress summary ongoing & future work LES simulations with nudging are able to properly simulate mean winds and turbulent fluctuations during morning transition in BL Model concentrations are strongly dependent on grid resolution  At 5m resolution EULAG concentrations agree perfectly with appropriate SCIPUFF run  At 2.5 m resolution model results are even overpredicting FFT07 concentrations at some locations (possible explanation: single release during Trial54 is compared to ensemble of 20 independent model realizations). Ongoing work: compare model results with Surface Layer Similarity theory (SLS) In near future:  Analyze different trials including fully convective and stable BL  Add support to missing data, unknown local valley and mesoscale tendencies with the WRF mesoscale forecast run over the DPG during FFT07 period  Updates to model SL/PBL parameterization (e.g. different roughness for momentum and heat, dynamic SGS models, etc).