Justin Glisan Iowa State University Department of Geological and Atmospheric Sciences
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Justin Glisan Iowa State University Department of Geological and Atmospheric Sciences RACM Project Update: ISU Atmospheric Modeling Component: Part 1 6th DOE/RACM Meeting: Boulder, CO 1 Justin Glisan, Iowa State University
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RACM Project Update: ISU Atmospheric Modeling Component: Part 1. Justin Glisan Iowa State University Department of Geological and Atmospheric Sciences. Outline. Update since Santa Cruz CORDEX Production runs Era-Interim Reanalysis 1989 - 2007 Arctic CORDEX Domain Six member ensemble - PowerPoint PPT Presentation
Transcript of Justin Glisan Iowa State University Department of Geological and Atmospheric Sciences
Justin GlisanIowa State University
Department of Geological and Atmospheric Sciences
RACM Project Update: ISU Atmospheric Modeling Component: Part 1
6th DOE/RACM Meeting: Boulder, CO 1Justin Glisan, Iowa State University
Outline• Update since Santa Cruz• CORDEX Production runs
– Era-Interim Reanalysis – 1989 - 2007– Arctic CORDEX Domain– Six member ensemble
• Observational Analysis of Extremes• Spectral Nudging on the wr50a domain
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Update since Santa Cruz
• Three inter-connected projects– CORDEX production runs– Observational analysis of extremes– Spectral nudging (Based on Matt Higgins work at
CU)• Running RACM CCSM12 on Pingo
CORDEX Production Runs
CU physicsEra-Interim Reanalysis
NSIDC sea ice
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PAW on Arctic CORDEX
• WRFV3.1.0 w/ CU Physics • Arctic CORDEX Domain• Forcing data sets:
– Era-Interim Reanalysis – NSIDC Bootstrap Fractional Sea Ice
• Six-member ensemble – One day stagger (01-06 January 1989)– January 1989 - December 2007
Justin Glisan, Iowa State University 5
January 1999 July 1999
January 2007 July 2007
Obs. RMSD and Variability
• Reanalysis RMSD provides another measure of internal variability in the atmosphere
• Magnitudes of both RMSD curves correspond to a high degree, including the seasonal variability.
• Thus, the model versus reanalysis RMSD:• May have a considerable dependence on
unforced, quasi-random internal variability• Also simulates the annual cycle of that variability
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Observational Analysis of Extremes
North American stationsPrecipitation and Temperature
Domain of Interest
• Arctic CORDEX Domain (1989 - 2007)• NCDS Global Summary of the Day
– Around 150 stations– Precipitation and Temperature
• Four analysis boxes– Based on the climatological record, weather
patterns– Physical location within the domain
• Each station is considered an individual realization within each box; hence each realization has a large number of samples, adding many degrees of freedom for statistical analysis.
• Observations are ordered and ranked by precipitation amount or temperature and then using the 95th percentile the extreme values are found using a suite of statistical programs. Further analysis is performed to determine extreme temporal and spatial regimes in temperature and precipitation.
Spectral Nudging on wr50a Domain
RACM Atmospheric DomainFour different nudging coefficients
PAW Setup on wr50a• WRFV3.1.1 w/ CU physics• Full spectral nudging option• Three-member ensemble (one day stagger)• Two cases:
– Winter case: January 2007 (initialized in Dec.)– Summer case: July 2007 (initialized in June)
• Four nudging coefficients – Full (WRF default)– 1/2, 1/4, 1/8
ISU Polar WRF
Brandon FiselIowa State University
Department of Geological and Atmospheric Sciences
RACM May 2010
Outline
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• Motivations• Model setup• Short-term behavior• Longer simulation results
Definitions
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Binary Fraction0 0% - 49%1 50% - 100%
Motivations
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• WRF sea-ice:• fraction v. binary
• Fractions • ocean-atmosphere interactions• dynamical behavior• climatological behavior
2007, July Sea Ice
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July 2007
Large area, >50%
Model Setup
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Cordex domain50-km resF; FractionB; Binary
B
F/BB
Model Setup (cont…)
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• Ensemble• Taschetto et al.• 8 members• BC:6-hr; 12-hr sea ice
• 2 treatments• fraction/binary
Simulations
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• Init. ~1.5-2 weeks• May 24, 2007
• Target – June 6, 2007• sea-ice >50%
2-week Behavior
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• Short-term• 2 weeks• May - June
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2-week Behavior (cont…)
F-BF-B(1-4)F-B(5-8)
MSLP
MSLP Avg.
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MSLP Avg. (cont…)
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MSLP Avg. (cont…)
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MSLP Avg. (cont…)
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MSLP Avg. (cont…)
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MSLP Avg. (cont…)
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MSLP Avg. (cont…)
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August
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October
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Aug/Oct Differences
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October 2m-T
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Concluding Remarks
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• August differences• unforced bifurcation
• October differences• low-level T differences• occur along focus area• significant?
Questions
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Daily Variance
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Daily Variance (cont…)
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ENS-Large
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ENS-Large (cont…)
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ENS-Large (cont…)
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ENS-Large (cont…)
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ENS-Large (cont…)
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