Evaluacion de Radiacion y Microfisica en Zonas Polares

8/18/2019 Evaluacion de Radiacion y Microfisica en Zonas Polares

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Evaluation of WRF Radiation and MicrophysicsParameterizations for use in the Polar Regions

Mark W. Seefeldt

Michael Tice

Department of Engineering – Physics – SystemsProvidence College

Cooperative Institute for Research in Environmental Sciences (CIRES)

University of Colorado at Boulder

Atmospheric Model Parameterizations in the Polar Regions WorkshopBoulder, CO – July 12, 2012


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Outline

• Objective / Motivation

• WRF General Configuration

• Radiation Parameterizations

• Microphysics Parameterizations

• Observations for Evaluation

• Statistical Comparisons• WRF 3.0 Physics Evaluation (2009)


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Objective

• The preferred physics parameterizations in the

polar regions is still under debate and evaluation

• e purpose o s s u y s o eva ua e a su e oradiation and microphysics parameterizations for

the use of the WRF model in the polar regions

• The anticipated outcome is the identification of abest-use combination of microphysics and radiation

• A secondary goal is the elimination of several of the

physics parameterizations as viable options


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WRF in the Polar Regions

• Atmospheric models have been found to have difficulty inreproducing representative conditions in the polar regions

(Wyser et al. 2008)

e pro ems are genera y re a e o e a mosp er c p ys cs

cloud processes

radiation

processes

PBL and surface fluxes

sea ice / icecovered land

WRF-ARW Version 3

Modeling SystemUser’s Guide


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WRF Physics Parameterizations

• There are seven general WRF physics

parameterizations:

– ra a on – s or wave ra_ w_p ys cs – radiation – longwave (ra_sw_physics)

– microphysics (mp_physics)

– cumulus (cu_physics)

– boundar la er bl_ bl_ h sics

– surface layer (sf_sfclay_physics)

– land surface model (sf_surface_physics)


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WRF Physics Parameterizations• The performance of a given physics parameterization is often

related to the associated parameterizations

•

The most complete way to identify the preferred physicsparameterizations is to evaluate different physics combinations

WRF Tutorial


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WRF Physics Evaluation – Summary

• This study will focus on the performance of the

radiation and microphysics parameterizations

• e s u y w compare s mu a ons anobservations for two locations:

Barrow, Alaska Summit, Greenland

• The month-long climate simulations will be evaluated

against observations of meteorology (surface and

upper- eve , c ou s, an ra at on• A statistical evaluation will be completed with the

results providing a ranking of the preferred

parameterizations


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WRF Physics Evaluation – General Configuration

• WRF-ARW v3.4 (released April, 2012)

• month-long climate simulations:

- - ,

• simulations for four different months covering different seasonal

and radiation forcing conditions:

October 2011, January 2012, April 2012, July 2012• Initial and lateral boundary conditions: ERA-Interim

• Fractional sea ice: NSIDC Near Real-Time DMSP SSMI

• Domains: outer – 50 km, inner – 10 km (one-way nesting)• Vertical: 40 levels with a 50 mb top

• Timestep : 50 km – 300 s, 10 km – 60 s

• Post-processing: CF NetCDF files using wrfout_to_cf.nclhttp://foehn.colorado.edu/wrfout_to_cf/


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WRF Physics Evaluation – Domains

• Two domains: Barrow – Alaska, Summit Camp – Greenland


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WRF Physics Evaluation – Non-Varying Physics

General Physics:

•Land surface model (sf_surface_physics): Noah LSM (2)

•Surface Layer (sf_sfclay_physics): Eta (2)•Boundary layer (bl_pbl_physics): MYJ (2)

•Cumulus (cu_physics): Grell-Devenyi (3)

•Fractional Sea Ice (fractional_seaice = 1)

•SST Updates (sst_update = 1 – uses wrflowinp_d0n)


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WRF Physics – Radiation Parameterizations

• Limit the shortwave (ra_sw_physics) and longwave(ra_lw_physics) radiation parameterizations to paired selections

• Four selected radiation combinations (LW / SW):

– o ar w_ -sw_ – CAM / CAM (lw_3-sw_3)

– RRTMG / RRTMG (lw_4-sw_4)

– New Goddard / New Goddard (lw_5-sw_5)

• RRTM / Goddard was selected because of its use in past WRF


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WRF Physics – Radiation Parameterizations

To be evaluated:• RRTM / Goddard (lw_1-sw_2)

• CAM / CAM (lw_3-sw_3)

• RRTMG / RRTMG (lw_4-sw_4)• New Goddard / New Goddard (lw_5-sw_5)

Eliminated:

• Dudhia (1) shortwave scheme was not selected based on poor

• Fu-Liou Gu (7/7) was not selected as it is a new scheme with no

particular known strengths for the polar regions

• GFDL (99/99) was not chosen as it is old and being phased out


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WRF Physics – Microphysics Parameterizations

• Eliminate the warm-rain and 3-phase parameterizations: – Kessler (1)

– WRF Single-Moment 3-class (3)

NCEP models:

– Eta (5) / (95)

• Eliminate the WRF double-moment parameterizations:

– WRF Double-Moment 5-class (14)

– WRF Double-Moment 6-class (16)

• m nate severe storm ocuse parameter zat ons:

– NSSL 2-moment (17, 18)

• Eliminate the 7-class paratmerization:

– Milbrandt-Yau Double-Moment 7-class (9)


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WRF Physics – Microphysics Parameterizations

To be evaluated – seven

microphysics parameterizations:•Lin et al. (2)

•WRF Single-Moment 5-class (4)

•WRF Single-Moment 6-class (6)•Goddard (7)

•New Thompson (8)

•Morrison Double-Moment (10)

•Stony Brook University (Lin) (13)


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WRF Physics Evaluation – Simulations Summary

Summary of simulations:• Two domains (Barrow, AK and Summit Camp)

– evaluating the 50 km and the 10 km domains separately

• Four months (October 2011, January, April, July 2012)• Four radiation parameterization combinations

• Seven microphysics parameterizations

Total number of simulations:

x x x = s mu at ons


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WRF Physics Evaluation – Observations

• Reviewed the available the data from the International ArcticSystems for Observing the Atmosphere (IASOA) observatories

http://iasoa.org/


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Barrow, Alaska – 71.323 N, 156.609 W, 11 m asl:http://www.esrl.noaa.gov/gmd/obop/brw/

Summit, Greenland – 72.580 N, 38.48 W, 3238 m asl:

http://www.geosummit.org/


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Evaluating WRF using observations from Barrow and Summit:• surface meteorology (temperature, pressure, dew point /

mixing ratio, wind speed)

• upper-a r meteoro ogy temperature, e g t, pressure,moisture)

• surface radiation (downwelling longwave, downwelling

shortwave)• radar and microwave (IWP, LWP)


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WRF Physics – Statistical Comparisons

• Monthly time series plots comparing WRF simulations toobservations will be created

• Statistical measures of bias, RMSE, and correlation will be


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WRF Physics – Statistical Comparisons

• The statistical performance for each radiation and microphysics

combination will be evaluated for each month and each domain

• The rankings of the statistical comparisons will be used todetermine preferred radiation and microphysics parameterizations

• Evaluation of the time series plots can be conducted to dig

further into the statistical comparisons


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WRF 3.0 Physics Evaluation (ca. 2009)• Goal: identify preferred radiation and microphysics parameterizations

– radiation – 5 combinations (lw-sw): RRTM-Dudhia,

RRTM-Goddard, RRTM-CAM, CAM-Goddard, CAM-CAM

– microphysics – 6 schemes:Lin, WSM5, WSM6, Goddard, Thompson, Morrison

• Observations:

– Barrow – Baseline Surface Radiation Network – SHEBA – Surface-Met Tower, Cloud Radiation

, , , ,

liquid water path (SHEBA), ice water path (SHEBA)

• Evaluate: over different months: January, March, May, June

• Evaluate: 10 km domain versus 50 km domain


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WRF 3.0 Physics Evaluation (ca. 2009)• The WRF results are compared against observations from the SHEBA met tower

and Barrow – Baseline Surface Radiation Network

observations:

-longwave downward-shortwave downward-2 m temperature-surface pressure

SHEBA only:-LWP-IWP

Statistics are calculatedto objectively evaluatethe performance of themodel in comparison to

the observations.

Correlation, Bias (WRF – obs), Root Mean Square Error (RMSE)


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WRF 3.0 Physics Evaluation (ca. 2009)• The statistics of each sensor for each physics configuration, location, month, and

model domain are aggregated together in a list

Note: The values for all 30 physics configurations and the different sensors have been

removed for display.

Each sensor statistic for each physicsconfiguration is ranked by performance (1-30)

The average rank and standarddeviation is calculated for each sensor

h l


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WRF 3.0 Physics Evaluation (ca. 2009)• The average of the three primary sensors (2 m temperature, shortwave downward,

and longwave downward) is calculated for each domain and location

Note: The values for Barrow have been removed to simplify the display.

WRF 3 0 Ph i E l i ( 2009)


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WRF 3.0 Physics Evaluation (ca. 2009)• The average rank for each physics configuration is calculated across the different

domains, months, and locations.

• The physics parameterizations are sorted by the average rank, from best to worst

WRF 3 0 3 S (T SW LW) R ki


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WRF 3.0 – 3 Sensor (T, SW, LW) Rankings• The CAM-CAM (3-3) radiation combination shows

consistently the best performance (4 of top 8)

• The Goddard (7) microphysics is a strong showing with the

top 3 performances

• Overall, the CAM-Goddard (3-2) and RRTM-CAM (1-3)radiation schemes perform well

• The RRTM-Dudhia (1-1) and RRTM-Goddard radiationcombinations do not do well

• The Lin (2) and Morrison (10) microphysics schemes do very poorly, no matter the radiation combination

WRF 3 0 5 S (T SW LW IWP LWP)


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WRF 3.0 – 5 Sensor(T, SW, LW, IWP, LWP)• The CAM-CAM (3-3) radiation continues to perform well

(5 of top 11)

• The Goddard (7) and Lin microphysics does well followed

by the WSM5 (4) and WSM6 (6)

• The RRTM-CAM (1-3) radiation performs fair, but all otherthan CAM-CAM have a mixture of results

• The Morrison (10) microphysics scheme continues to dooorl

RRTM Goddard (1 2) Morrison (10) May 1998


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RRTM – Goddard (1-2), Morrison (10) – May 1998

CAM CAM (3 3) Goddard (7) May 1998


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CAM – CAM (3-3), Goddard (7) – May 1998

Sh t d L R di ti R ki


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Shortwave and Longwave Radiation Rankings• The CAM SW (3) consistently does very well

with the SW rankings (top 8)

• The Goddard SW (2) does moderate withSW rankings

• The Dudhia SW (1) performs very poorly with the SW sensor

• The CAM LW (3) does well, but not

spectacular with LW rankings• The RRTM LW (1) does well when matched

with Dudhia SW (1) but not Goddard SW orCAM SW (3)

• The CAM-CAM (3-3) radiation combinationprovides the best results

Liq id Water Path and Ice Water Path Rankings


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Liquid Water Path and Ice Water Path Rankings• The Goddard (7) and Thompson (8) show

consistently good performance with LWP(6 of top 7)

• The Lin (2) and Morrison (10) do poorly w

• The Lin (2) and Morrison (10) do very well with IWP

• The Goddard does poorly with IWP

• Overall, using LWP and IWP is suspect asthe model results showed limited success(i.e. LWP in January)

WRF 3 0 Physics Evaluation (ca 2009) Summary


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WRF 3.0 Physics Evaluation (ca. 2009) - Summary

• The CAM-CAM (3-3) radiation combination consistentlyperforms with the best results in nearly every ranking and

categorization

e - - an - o ar - per orms

reasonable, but not as good as CAM-CAM

• The results for the microphysics is not as clear and will requirefurther analysis

• The Goddard (7) microphysics scheme could be classified as

strongest, but with some questions


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Mark Seefeldt [email protected]

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Evaluacion de Radiacion y Microfisica en Zonas Polares