1. Polar WRF (Ohio State Modifications)
Brandon Fisel
Iowa State University
Department of Geological and Atmospheric Sciences
RACM Presentation 2008 December 05

2. Motivations Model Setup Plots Future Directions
Outline
Motivations
Model Setup
Plots
Future Directions
RACM Presentation 2008 December 05

3. Simulations in polar climates Polar optimizations Treatment of sea ice
Motivations
Simulations in polar climates
Polar optimizations
Treatment of sea ice
Climate regimes: polar oceans, ice sheets, arctic land.
Optimizations done to PBL parameterizations, snow surface physics, treatment of land surface.
Polar WRF allows for different surface conditions for ice and open water portions of sea-ice grid points; includes parameters, surface roughness and albedo between open water and sea-ice.
RACM Presentation 2008 December 05

4. Model Setup Pan-Arctic domain SHEBA year (Oct. 97 – Oct. 98)
ERA40/ECMWF-TOGA
NSIDC sea ice concentrations
Using SHEBA year right but not a year of focus now. I will perform diagnostics on the fractional sea ice (variance in space of sea ice) to determine when we can focus on this.
RACM Presentation 2008 December 05

5. Model Setup (cont…) RACM Presentation 2008 December 05
Using SHEBA year right but not a year of focus now. I will perform diagnostics on the fractional sea ice (variance in space of sea ice) to determine when we can focus on this.
RACM Presentation 2008 December 05

6. Model Setup (cont…) External Data Sources WPS WRF GRIB NSIDC
geogrid.exe
ungrib.exe
metgrid.exe
WRF
WRF (V )
Polar WRF (V )
RACM Presentation 2008 December 05

7. Model Setup (cont…) External Data Sources WPS WRF GRIB NSIDC
geogrid.exe
ungrib.exe
metgrid.exe
WRF
WRF (V )
Polar WRF (V )
PHYS – physics_init, sf_noahdrv, sf_noahlsm, surface_driver
RUN – LANDUSE, VEGPARM
SHARE – soil_pre
WPS – seaice-intermd
RACM Presentation 2008 December 05

8. Model Setup (cont…) NSIDC (sea ice) Real wrfinput_d01 wrfbdy_d01 WPS
met_em.d01
WRF
TOGA
ERA40
wrfout_d01
Real.exe interpolates the met_em files vertically, creates wrfinput and wrfbdy files, and performs consistency checks.
RACM Presentation 2008 December 05

9. Model Setup (cont…) Issues: External data sea-ice to intermediate
(Keith Hines & Francis Otieno)
configure.wrf
CPP = /lib/cpp –C –P
CPP = /lib/cpp –C –P –D_BPRC_SEAICE_ -D_BPRC_POLAR_
ERA40 used to substitute sub-surface data while ECMWF-TOGA (no soil T) used to supply everything else.
RACM Presentation 2008 December 05

10. NSIDC sea ice concentration
Plots
NSIDC sea ice concentration
Oct. 97 – Oct. 98
RACM Presentation 2008 December 05

11. Initial hypothesis Fractional sea ice Simulations
Future Directions
Initial hypothesis
Fractional sea ice
Simulations
Heating by open fraction of the ocean will have a significant effect on the atmospheric circulation but only at times when the circulation is susceptible to bifurcation (small changes that can impact the short-term dynamical behavior).
Simulations using Polar WRF w/ fractional sea-ice and Polar WRF w/o fractional sea-ice.
Fractional sea-ice variance over space and not time. (diagnostic to locate periods to focus on)
RACM Presentation 2008 December 05

12. Questions
RACM Presentation 2008 December 05