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Recent performance statistics for AMPS real-time forecasts. Kevin W. Manning – National Center for Atmospheric Research NCAR Earth System Laboratory Mesoscale and Microscale Meteorology Division Boulder, CO – NCAR is sponsored by the National Science Foundation –
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Recent performance statistics for AMPS real-time forecasts Kevin W. Manning – National Center for Atmospheric Research NCAR Earth System Laboratory Mesoscale and Microscale Meteorology Division Boulder, CO – NCAR is sponsored by the National Science Foundation – AMPS is sponsored by the NSF Office of Polar Programs and theNSF UCAR and Lower Atmosphere Facilities Oversight Section – Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model 02-03 Nov 2011, Columbus, OH –
AMPS real-time forecasts • 6 two-way interactive grids: • 45-km / 15-km grids to 120 forecast hours • 5-km / 1.67-km grids to 36 forecast hours • Initial conditions • GFS 0.5-degree analyes used as first guess for WRFDA 3D variational data assimilation step (domains 1 and 2) • Sea-ice conditions from near real-time SSM/I daily global ice concentration (NSIDC) (25-km grid) • Domain 1 boundary conditions • GFS 0.5-degree forecast updated at 6-hour intervals • WRF options • 44 vertical levels; lowest half level ~ 12 m above surface; 12 layers below ~1 km above surface • Microphysics: WSM 5-class scheme • LW Radiation: RRTMG • SW Radiation: Goddard SW scheme • Surface Layer Physics: Monin-Obukhov (Janjic Eta) scheme • Land Surface: Noah Land-surface model; 4 subsurface layers • PBL Physics: MYJ (Eta) TKE scheme Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
AMPS statistics – Summertime Surface • Nov-Dec-Jan 2010/2011 season • Temperature • Pressure • Wind • Surface station reports • From GTS • From University of Wisconsin – Antarctic Meteorological Research Center (AMRC) • Three regions • Ross Ice Shelf • East Antarctic plateau • East Antarctic coastal • Older WRF version 3.0.1.1 with Polar modifications Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
Summer T – Ross Ice Shelf Mean Statistics -- ~ 15 stations Forecast Hour (0 – 120) Bias RMSE Correlation (-1.0 to 1.0) Forecast Hour (0 – 120) Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
Summer T – East Antarctic Plateau Mean Statistics ~ 6 stations Forecast Hour (0 – 120) Bias RMSE Correlation (-1.0 to 1.0) Forecast Hour (0 – 120) Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
Summer T – East Antarctic Coastal Mean Statistics -- ~10 stations Forecast Hour (0 – 120) Bias RMSE Correlation (-1.0 to 1.0) Forecast Hour (0 – 120) Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
Summer P – Ross Ice Shelf Mean Statistics -- ~ 15 Stations Forecast Hour (0 – 120) Bias RMSE Correlation (-1.0 to 1.0) Forecast Hour (0 – 120) Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
Summer P – East Antarctic Plateau Mean Statistics -- ~ 6 stations Forecast Hour (0 – 120) Bias RMSE Correlation (-1.0 to 1.0) Forecast Hour (0 – 120) Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
Summer P – East Antarctic Coastal Mean Statistics -- ~10 stations Forecast Hour (0 – 120) Bias RMSE Correlation (-1.0 to 1.0) Forecast Hour (0 – 120) Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
Summer Wind Speed – Ross Ice Shelf Mean Statistics -- ~ 15 stations Forecast Hour (0 – 120) Bias RMSE Correlation (-1.0 to 1.0) Forecast Hour (0 – 120) Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
Summer Wind Speed – East Antarctic Plateau Mean Statistics -- ~ 6 stations Forecast Hour (0 – 120) Bias RMSE Correlation (-1.0 to 1.0) Forecast Hour (0 – 120) Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
Summer Wind Speed – East Antarctic Coastal Mean Statistics -- ~10 stations Forecast Hour (0 – 120) Bias RMSE Correlation (-1.0 to 1.0) Forecast Hour (0 – 120) Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
Summertime Summary • Warm bias on plateau. Mixed temperature bias in other regions. • Warming trend in East Antarctic plateau and Ross Ice Shelf regions. Very little temperature trend for coastal stations. • Plateau stations show greatest temperature error growth (RMSE) over 120 hours. Little temperature error growth (RMSE) for Ross Ice Shelf and coastal regions. • Pressure statistics show high correlation in all three regions, but steady error (RMSE) growth. • Low pressure bias increasing in time over Ross Ice Shelf. • Slight high wind-speed bias Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
AMPS Behavior – Wintertime Surface • May-Jun-Jul 2011 • Newer WRF version 3.2.1 with Polar Modifications Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
Winter T -- Ross Ice Shelf region Mean Statistics -- ~21 stations Forecast Hour (0 – 120) Bias RMSE Correlation (-1.0 to 1.0) Forecast Hour (0 – 120) Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
Winter T -- East Antarctic Plateau Mean Statistics – ~13 stations Forecast Hour (0 – 120) Bias RMSE Correlation (-1.0 to 1.0) Forecast Hour (0 – 120) Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
Winter T -- East Antarctic Coastal Mean Statistics -- ~15 stations Forecast Hour (0 – 120) Bias RMSE Correlation (-1.0 to 1.0) Forecast Hour (0 – 120) Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
Winter P -- Ross Ice Shelf region Mean Statistics -- ~21 stations Forecast Hour (0 – 120) Bias RMSE Correlation (-1.0 to 1.0) Forecast Hour (0 – 120) Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
Winter P -- East Antarctic Plateau Mean Statistics -- ~13 stations Forecast Hour (0 – 120) Bias RMSE Correlation (-1.0 to 1.0) Forecast Hour (0 – 120) Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
Winter P -- East Antarctic Coastal Mean Statistics -- ~15 stations Forecast Hour (0 – 120) Bias RMSE Correlation (-1.0 to 1.0) Forecast Hour (0 – 120) Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
Winter Wind Speed -- Ross Ice Shelf region Mean Statistics -- ~21 stations Forecast Hour (0 – 120) Bias RMSE Correlation (-1.0 to 1.0) Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
Winter Wind Speed – East Antarctic Plateau Mean Statistics -- ~13 stations Forecast Hour (0 – 120) Bias RMSE Correlation (-1.0 to 1.0) Forecast Hour (0 – 120) Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
Winter Wind Speed -- East Antarctic Coastal Mean Statistics -- ~15 stations Forecast Hour (0 – 120) Bias RMSE Correlation (-1.0 to 1.0) Forecast Hour (0 – 120) Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
Wintertime summary • In each region, a mix of high and low temperature biases – average bias near zero. • Over plateau, strong signal of initial condition warm bias that the model quickly corrects. • Larger temperature error (RMSE) growth, larger reduction of temperature correlation, than we saw in summer. • As in summer, pressure statistics show significant error growth (RMSE) • High wind speed bias, more notable than in summer. Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
Subsurface Temperature Initialization • BPRC Antarctic results differ from AMPS results • BPRC results show cold bias in summer over East Antarctic Plateau • AMPS results show warm bias in summer over East Antarctica Plateau • One possibly significant difference in the AMPS and BPRC is the initialization of subsurface temperature fields • AMPS cycles the subsurface temperature from one forecast to the next • High resolution details • In balance with WRF physics • Subject to model drift • BPRC initializes subsurface temperature fields using a 40-year annual mean air temperature analysis at deep ice layers, and a 40-year monthly mean air temperature analysis at the shallowest subsurface layer • No spin-up required • Low resolution • Could this account for the different results for forecasts of air temperature? Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
Two experiments • Cycled subsurface temperature fields (CYCLE) • Subsurface temperature fields initialized from monthly mean and annual mean temperatures (MEANT) • Two 72-hour forecasts per day, in the AMPS 45km/15km configuration, from 10 Jan through 06 Feb 2011 (about 4 weeks). • The CYCLE conditions have been spun up for about 6 weeks, starting from AMPS real-time fields (i.e., already using the real-time cycled conditions) from 01 Dec 2010. Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
CYCLE Level 2 (-0.25 m) Ice T MEANT Level 2 (-0.25 m) T Averages at Forecast hour 00 Difference Level 2 T (-0.25 m) CYCLE – MEANT Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
CYCLE Level 4 (-1.5 m) Ice T MEANT Level 4 (-1.5 m) Ice T Averages at Forecast hour 00 Difference Level 4 T (-1.5 m) CYCLE – MEANT Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
CYCLE 2-m air Temperature MEANT 2-m air Temperature Averages at Forecast hour 72 Difference 2-m air T CYCLE – MEANT Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model
Short-term plans for sea-ice code in WRF, particularly Noah LSM • Currently, sea-ice code is scattered throughout the Noah LSM code • Difficult to trace the sea-ice processes through the code • Difficult to develop or replace • Plan: Pull sea-ice code out of Noah-LSM, and make the Noah sea-ice treatment its own separate WRF module • Easy to trace the sea-ice processes through the code • Easy to develop or replace • A place to link up with more sophisticated sea-ice schemes or models • Easy to use with other LSM options (e.g., the new Noah-MP LSM) Workshop on Polar Simulations with the Weather Research and Forecasting (WRF) Model