narccap users meeting 14-15 february 2008 narccap multi-model simulations: initial ncep-driven...
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NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
NARCCAP Multi-Model Simulations:NARCCAP Multi-Model Simulations:Initial NCEP-Driven ResultsInitial NCEP-Driven Results
Bill Gutowski, Bill Gutowski, Ray ArrittRay Arritt, Gene Takle, , Gene Takle, Dave FloryDave Flory, , John BaranickJohn Baranick
(Iowa State University)(Iowa State University)andand
The NARCCAP Modelers TeamThe NARCCAP Modelers Team
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
NARCCAP ParticipantsNARCCAP Participants
• Raymond Arritt, David Flory, William Gutowski, Gene Takle, Iowa State University, USA
• Richard Jones, W. Moufouma-Okia, Hadley Centre, UK• Daniel Caya, Sébastien Biner, OURANOS, Canada• David Bader, Phil Duffy, Lawrence Livermore National Laboratories, USA• Filippo Giorgi, Abdus Salam ICTP, Italy• Isaac Held, NOAA Geophysical Fluid Dynamics Laboratory, USA• René Laprise, Univ. de Québec à Montréal, Canada• Ruby Leung, Y. Qian, Pacific Northwest National Laboratories, USA• Linda Mearns, Don Middleton, Doug Nychka National Center for Atmospheric
Research, USA• Ana Nunes, John Roads, Scripps Institution of Oceanography, USA• Steve Sain, Univ. of Colorado at Denver, USA• Lisa Sloan, Mark Snyder, Univ. of California at Santa Cruz, USA
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
Comparison with observationsComparison with observations
• ObservationsObservations Precip: University of Washington VIC retrospective analysisPrecip: University of Washington VIC retrospective analysis
500 hPa Heights: North American Regional Reanalysis500 hPa Heights: North American Regional Reanalysis
• Comparison period: 1980-1999Comparison period: 1980-1999 1979 omitted - (a) spinup (b) WRFP began 1 Sep 791979 omitted - (a) spinup (b) WRFP began 1 Sep 79 UW data end in mid-2000UW data end in mid-2000
• Analyses: monthly mean precipitation & 500 hPa ZAnalyses: monthly mean precipitation & 500 hPa Z Fields received at Iowa State for format checkFields received at Iowa State for format check
For several regions in the U.S. (UW analysis extends to ~ 53For several regions in the U.S. (UW analysis extends to ~ 53ooN)N)
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
Regions AnalyzedRegions Analyzed
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
Coastal CaliforniaCoastal California
• Mediterranean climate: wet winters and dry summers (Koeppen types Csa, Csb)
• ENSO can have strong effects on interannual variability of precip
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
Monthly precipitation for coastal California
0
2
4
6
8
10
12
14
1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
mm/day
RCM3 MM5I
ECPC MRCC
Observed (UW) Ensemble Mean
1982-83 El Nino
1997-98 El Nino
multi-year drought
Monthly Time Series - Coastal CAMonthly Time Series - Coastal CA
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
Time Series Correlations - Coastal CATime Series Correlations - Coastal CA
Model Correlation
RCM3 0.946
MM5I 0.946
ECPC 0.966
MRCC 0.959
Ensemble 0.968
Monthly precipitation for coastal California
0
2
4
6
8
10
12
14
1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
mm/day
RCM3 MM5I
ECPC MRCC
Observed (UW) Ensemble Mean
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
Mean annual cycle, coastal California
0
1
2
3
4
5
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
mm/day
RCM3 MM5I
ECPC MRCC
Obs (UW) Ensemble
Monthly mean precipitation, mm/day
0
2
4
6
8
10
12
0 2 4 6 8 10 12
Observed
Ensemble mean
Further Statistics - Coastal CAFurther Statistics - Coastal CA
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
1997-1998 El Ni1997-1998 El Niññoo
• Strongest El Niño in the instrumental record.
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
October 1997RegCM3
MRCC MM5
RSM
Observed (CRU)
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
January 1998RegCM3
MRCC MM5
RSM
Observed (CRU)
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
March 1998RegCM3
MRCC MM5
RSM
Observed (CRU)
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
Monthly precipitation for coastal California
0
2
4
6
8
10
12
14
1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
mm/day
RCM3 MM5I
ECPC MRCC
Observed (UW) Ensemble Mean
Circulation with Extreme PrecipitationCirculation with Extreme PrecipitationPrecip. Max.: Feb 1998 Precip. Max.: Feb 1998
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
Simulated Simulated Circulation Circulation
with Extreme with Extreme PrecipitationPrecipitation
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Deep SouthDeep South
• Humid mid-latitude climate with little seasonality in precip amount (Koeppen type Cfa).
• Past studies have found problems with RCM simulations of cool-season precip in this region.
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
Monthly precipitation for Deep South
0
2
4
6
8
10
12
14
1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
mm/day
RCM3 MM5IECPC MRCCObserved (UW) Ensemble Mean
Monthly Time Series - Deep SouthMonthly Time Series - Deep South
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
Monthly precipitation for Deep South
0
2
4
6
8
10
12
14
1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
mm/day
RCM3MM5IECPCMRCCObserved (UW)Ensemble Mean
ModelModel CorrelationCorrelation
RCM3 0.257
MM5I 0.377
ECPC 0.636
MRCC 0.645
Ensemble 0.597
Ensemble of MRCC and ECPC
0.709
ECPC and MRCC both incorporate ECPC and MRCC both incorporate large-scale information in the domain large-scale information in the domain interior: ECPC is a perturbation model interior: ECPC is a perturbation model (RSM), while MRCC uses spectral (RSM), while MRCC uses spectral nudging. nudging.
Time Series Correlations - Deep SouthTime Series Correlations - Deep South
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
Mean annual cycle, Deep South
0
1
2
3
4
5
6
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
mm/dayRCM3 MM5I
ECPC MRCC
Obs (UW) Ensemble
Monthly mean precipitation, mm/day
0
2
4
6
8
10
0 2 4 6 8 10Observed
Ensemble mean
too dry in the cool half of the year
high rates (> 4 mm/day) are underpredicted
Further Statistics - Deep SouthFurther Statistics - Deep South
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
Monthly precipitation for Deep South
0
2
4
6
8
10
12
14
1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
mm/day
RCM3MM5IECPCMRCCObserved (UW)Ensemble Mean
Circulation with Extreme PrecipitationCirculation with Extreme PrecipitationPrecip. Max.: April 1991 Precip. Max.: April 1991
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
Simulated Simulated Circulation Circulation
with Extreme with Extreme PrecipitationPrecipitation
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
Comments and speculationsComments and speculations
• A simple unweighted ensemble mean usually A simple unweighted ensemble mean usually performs better than the best individual model, or performs better than the best individual model, or close to the best model when spread is large.close to the best model when spread is large.
• Hypothesis: Downscaling of ENSO could be an Hypothesis: Downscaling of ENSO could be an especially suitable use for a coupled GCM-RCM:especially suitable use for a coupled GCM-RCM:• RCMs perform well in coastal California during ENSORCMs perform well in coastal California during ENSO• Some AOGCMs can produce reasonable ENSO (see e.g., Some AOGCMs can produce reasonable ENSO (see e.g.,
Van Oldenborgh et al. 2005).Van Oldenborgh et al. 2005).• Two of these AOGCMs are used in NARCCAP: GFDL Two of these AOGCMs are used in NARCCAP: GFDL
CM2.1 and HadCM3.CM2.1 and HadCM3.
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
Comments and speculationsComments and speculations
• Incorporation of large-scale information into the RCM Incorporation of large-scale information into the RCM (whether through spectral nudging or use of a (whether through spectral nudging or use of a perturbation form of the governing equations) perturbation form of the governing equations) appears to be an advantage for the Deep South appears to be an advantage for the Deep South region.region.• This advantage does not carry over to other regions (or This advantage does not carry over to other regions (or
is outweighed by other factors, e.g., model physics).is outweighed by other factors, e.g., model physics).
5-Yr Return Period Amounts5-Yr Return Period Amounts[mm/day][mm/day]
OBSERVATIONSOBSERVATIONS
1980-19991980-1999
Thanks to Hayley Fowler for diagnostic codeThanks to Hayley Fowler for diagnostic code
5-Yr Return 5-Yr Return Period Period
AmountsAmounts[mm/day][mm/day] OBSOBS
MM5-PNLMM5-PNL
MM5-ISUMM5-ISU
MRCCMRCC
ECPCECPC
RegCM3RegCM3
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
Thank YouThank You
Further InformationFurther Information
1. General: 1. General: http://www.narccap.ucar.eduhttp://www.narccap.ucar.edu
2. Archive Information: 2. Archive Information: http://rcmlab.agron.iastate.edu/narccap/output_archive.htmlhttp://rcmlab.agron.iastate.edu/narccap/output_archive.html
3. Data portal: http://esg.ucar.edu/forward.htm?forward=narccap
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
EXTRAS
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
U.S. Corn Belt
• Western part is a continental climate with warm summers and cold winters becoming less continental to the east. (Koeppen types Dfa, Dfb)
• Maximum precipitation in April-June• seasonality of precip is important for agriculture, e.g.,
drawdown of soil moisture during the growing season
• Includes the Upper Mississippi River basin
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
0
1
2
3
4
5
6
7
8
9
1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
mm/day
Ensemble
Observed (UW) 1993 flood1988 drought
Model Correlation
RCM3 0.722
MM5I 0.692
ECPC 0.636
MRCC 0.760
Ensemble 0.788
Monthly precipitation, U.S. Corn Belt region
0
1
2
3
4
5
6
7
8
9
1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
mm/day
RCM3 MM5I
ECPC MRCC
Ensemble Observed (UW)
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
too wet in winter/spring
too dry in summer
low rates (< 2 mm/day) are overpredicted
high rates (> 4 mm/day) are underpredicted
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
Upper Mississippi River Basin
• Continental climate with warm summers and cold winters (Koeppen types Dfa, Dfb).
• Maximum precipitation in April-June:• seasonality of precip is important for impacts, e.g.,
drawdown of soil moisture during the growing season
• Most NARCCAP models simulated this region in the PIRCS project.
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
Monthly precipitation, Upper Mississippi River basin
0
1
2
3
4
5
6
7
8
9
1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
mm/day
RCM3 MM5I
ECPC MRCC
Ensemble Observed (UW)
0
1
2
3
4
5
6
7
8
9
1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
mm/day
Ensemble
Observed (UW)
1993 flood1988 drought
Model Correlation
RCM3 0.745
MM5I 0.696
ECPC 0.627
MRCC 0.779
Ensemble 0.791
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
Mean annual cycle, Upper Mississippi River basin
0
1
2
3
4
5
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
mm/day
RCM3 MM5I
ECPC MRCC
Obs (UW) Ensemble
too wet in winter/spring
too dry in summer
Monthly mean precipitation, mm/day
0
2
4
6
8
0 2 4 6 8
Observed
Ensemble mean
low rates (< 2 mm/day) are overpredicted
high rates are underpredicted
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
1982-1983 and 1997-98 El Niños
• Some AOGCMs give realistic simulation of ENSO:• see e.g., van Oldenborgh et al. (2005, Ocean Science) for
IPCC AR4 models
• Do regional models give realistic precipitation during El Niño events?• If so, perhaps a combined AOGCM-RCM approach can
give useful results for ENSO in future climates.
• We examine evolution of precipitation during the 1982-1983 and 1997-1998 El Niño: onset, peak, and withdrawal.
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
October 1982RegCM3
MRCC MM5
RSM
Observed (CRU)
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February 1983RegCM3
MRCC MM5
RSM
Observed (CRU)
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April 1983RegCM3
MRCCMM5
RSM
Observed (CRU)
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1993 flood in the north-central U.S.1993 flood in the north-central U.S.
• The event mainly was the result of synoptic-mesoscale dynamics with little direct influence by terrain.
• This event was the subject of an early regional model intercomparison which performed 60-day simulations (PIRCS, 1B).
NARCCAP Users MeetingNARCCAP Users Meeting 14-15 February 200814-15 February 2008
Summer 1993 flood in central U.S.RegCM3
MRCC MM5
RSM
Observed (CRU)
July 1993 precipitation
• model skill is very similar to PIRCS 1B
5-Yr Return 5-Yr Return Period Period
AmountsAmounts[mm/day][mm/day]
OBSOBS
ECPCECPC RegCM3RegCM3
5-Yr Return 5-Yr Return Period Period
AmountsAmounts[mm/day][mm/day]
OBSOBS
MM5-PNLMM5-PNL MRCCMRCC
5-Yr Return 5-Yr Return Period Period
AmountsAmounts[mm/day][mm/day]
OBSOBS
MM5-PNLMM5-PNL MM5-ISUMM5-ISU