jma monthly and seasonal forecast systems 1 yuhei takaya [email protected] climate prediction...
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JMA Monthly and JMA Monthly and Seasonal Forecast SystemsSeasonal Forecast Systems
1
Yuhei [email protected]
Climate Prediction DivisionJapan Meteorological Agency
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010
• Designing Operational Forecast Systems• Targets (Phenomena, Time scales, Applications)• Requirements/Limitations
• Current JMA Operational Systems• Monthly (uncoupled) and Seasonal (coupled)
forecast systems• Practical Examples
• Future Directions• Required Activities
Outline
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 20102
• Operational Forecast Systems are to be oriented to phenomena, user applications.
10 102 103 104
Time scale (hours)
Hor
izon
tal s
cale
(km
)
2
20
200
2,000
20,000
1d 10d 1m 3m
“Designing” Operational Forecast Systems
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 20103
ENSOMonsoon
MJO
Synoptic
Weather
Systems Teleconnection
sTropical
Cyclone
Seasonal EPS (CGCM TL95 180 km)
Monthly EPS , Early Warning on ExtremeEvents (TL159 110 km)
Weekly /Typhoon EPS (TL319 60 km)Deterministic (JMA-GSM, TL959 20 km)
JMA-NHM (5 km)LFM (2 km)
Atmospheric
convection
Mesoscale
Weather
System
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 20104
Current JMA Sub-seasonal to Seasonal Prediction Systems
1 month 3 months 7 months
Early warning information onextreme events
1-month forecast
3-month forecast
Warm/cold
season forecast
ENSOoutlook
operatedmodelsAGCM
TL159L6050 member
CGCMJMA/MRI-CGCM
AGCM: TL95L40OGCM:
0.3 -1 deg x 1 deg
51 member
2 weeks
week 1
Week 2
Week 3&4
1 month3 months
3 months(summer/winter)
ENSO, Indian Ocean SST
The seasonal forecast system and ENSO prediction system were integrated with an atmosphere-ocean coupled model in Feb. 2010. The seasonal forecast system and ENSO prediction system were integrated with an atmosphere-ocean coupled model in Feb. 2010.
Issued on Tuesday/Friday
Issued on Friday
Issued every month
Issued in Feb. Sep.
Issued every month
• Computer Resources• Costs & Benefits
Requirements and Limitations
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 20105
• Higher Resolution• Higher Frequency• More Members
T850Z500&WAF200Precipitation, PSI200, WAF200
X200 and Div WindSST
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T850Z500&WAF200
X200 and Div WindSST
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Precipitation, PSI200, WAF200
Precipitation, PSI200, WAF200
Predictability in the Midst of Chaos - Predictability at SSS Time Scale- (Shukla 1998 Science )
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 20108
JMA Monthly Forecast System
Atmospheric General Circulation Model(JMA-GSM0803C)
TL159L60 (~110km)
JMA Global Data Assimilation System
Atmospheric perturbationsTrop.&Ext.-trop. bred vector
Atmospheric I. C.
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 20109
JMA Land Surface Analysis
25 members start from Wednesday.25 members start from Thursday. 50 members in total
Arctic Oscillation during Dec. 2009-Feb. 2010
Dec. 2009
• A negative phase of the Arctic Oscillation (AO) pattern was dominant through Winter 2009/2010.
Jan. 2010 Feb. 2010
-300 -180 -60 0 60 180 300 [m]
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Forecast Skill of Operational JMA Monthly Forecast
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 201011
Week 1 Week 2 Week 3-4 Week 1-4
Ano
mal
y C
orre
latio
n
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AO index in Winter 2009/2010
(1) 2009/12/10 (2) 2010/1/28
Spatial Pattern of GPH500 EOF1 (Area weighted Covariance, 22.6 %)Computed with 1979-2005 DJF mean 500-hPa GPH.
Index of EOF1 score (500hPa GPH, DJF mean)
The winter 2009/2010 was the most prominent period during 1979-2010.
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010
• 1-month (4-week) mean Anomaly Correlation 0.84 Week 1 0.93, Week 2 0.77, Week 3-4 0.56
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Prediction for negative AO Case Initial Date: 2009/12/10
Analysis (JRA-25) Forecast
1-month ( 4-week ) mean 500-hPa GPH Anomaly
1209060300 -30-60-90-120[m]
0.84
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010
200-hPa Westerly Jet Initial Date: 2009/12/10
200-hPa Zonal Wind Anomaly 4-Week Mean Forecasts
Forecast I.C.; 2009/12/09 Forecast I.C.:2009/12/10Analysis (12/12-1/8)
[m/s] Strong Sub-tropical Jet Weak Polar Front Jet
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010
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• Momentum Transport Diagnostics: E-vector E=(v’2-u’2, -u’v’)
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E-vector (Hoskins et al. 1983 JAS)
E
Anti-CyclonicCirculation
Cyclonic Circulation
Divergence Convergence
Ian N. James (1994) “Introduction to Circulating Atmospheres”
Anti-CyclonicCirculation
Cyclonic Circulation
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010
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Divergence of E-vectorMid-latitude 30N-40N
North Pacific 30N-40N, 170E-120W
North Atlantic 30N-40N, 90W-0
● Hindcast (Initial Date: 10 Dec.) Operational Forecast (2009/12/10)○ JRA-25/JCDAS Analysis
x104 [m s-2]
x104 [m s-2]
x104 [m s-2]
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 201017
• The seasonal forecast relies on the predictability that comes from the ENSO variability.
• The East Asian monsoon is essentially an ocean-atmosphere-land coupled system.
• Coupled models are suitable for predicting its variability at a seasonal time scale.
JMA Seasonal EPS
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 201018
The new JMA coupled forecast system has been up and running for the JMA ENSO prediction system since Feb. 2008, and was introduced to the JMA seasonal forecast in Feb. 2010.
The new JMA coupled forecast system has been up and running for the JMA ENSO prediction system since Feb. 2008, and was introduced to the JMA seasonal forecast in Feb. 2010.
New JMA Seasonal Forecast System
coupler(w/ flux adjustment)
Climate Data AssimilationJRA-25/JCDAS
Atmosphere-Ocean Coupled model (JMA/MRI-CGCM)
JMA GSM( TL95L40: ~180km )
Ocean model (MRI.COM )
1.0°×(0.3°-1.0°), 51 levels
Ocean Data Assimilation System
MOVE/MRI.COM-G
Atmospheric perturbationsTrop.&Ext. trop bred vector
Atmospheric I. C.
Oceanic I. C.Atmospheric BGM + Lagged
Averaging Forecast
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 201019
Operational Schedule
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 201020
10 daysWindow
Ocean Data Assimilation
Forecasts9 members / 5 days
LAF
NINO3 SSTA
South China Flood in 2010
BBC News http://news.bbc.co.uk/2/hi/asia-pacific/4617891.stm
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 201021
Precipitation Forecasts for June 2010 (I.C. : May)
Beijing ECMWF Exeter Melbourne
Montreal Moscow Seoul Tokyo
Toulouse Washington
WMO LC website http://www.wmolc.org/
Observation; OLR anomaly
(mm/day)
Original data are provided by NOAA.
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• Weekly EPS • TL479L100 (~40 km) in 2013
• Monthly EPS• TL319L100 (~60 km) in 2013 • Development of integrated Weekly EPS and Monthly EPS
(Seamless system) is under discussion.
• Seasonal EPS• AGCM: TL159L60 (80?) (~110 km) in 2014• OGCM: Tripolar grid, 1deg x 0.3-0.5 deg. 53 levels.
JMA future plan on the next HPC
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 201023
• The lead time is important at a 1-month time scale.
Forecast Skill wrt Lead Time
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 201024
50 ensembles50 ensembles
Based on verification of real-time JMA operational forecasts in 2006.
ACC (Daily 500-hPa GPH) ACC (7-day mean 500-hPa GPH)
Scores if forecasts 3-day before used.
Toward “Seamless Prediction System”
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 201025
Weekly EPS(TL479L100)
2-Week EPS (Early Warning)
Monthly EPS (TL319L100)reforecast
2-Week EPS (TL479L100)reforecast
Monthly EPS (TL319L100)reforecast
2-Week EPS (TL479L100)reforecast
Monthly EPS (TL319L100)
Week-1 Week-2 Week-3 Week-4
FY2013-
FY ?
FY ???
• International research projects to investigate predictability at monthly time scale (extended TIGGE ???)
• International research projects for key processes of predictability, MJO, ENSO, etc… (CLIVAR MJO WG etc. )
• Standard verification framework for operational forecasts at sub-seasonal (monthly) time scale. (under WMO, CBS? SVS?)
Required Activities for Further Improvement of SSS time scale
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 201026
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 201027
END
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 201028
EOF1(AO), REOF(PNA, NAO) Scores Initial Date: 2009/12/10
(a) EOF1 22.6 %
(b) REOF1 16.6 % (c) REOF2 16.1 %
AO, NAO, PNA Indices were well predicted.
Red : Ensemble meanBlue : AnalysisGrey : Each realization
Contours: 300-hPa Zonal Wind Anomaly [m s-1] Colors: High-Frequent Wave Activity Anomaly x 10-5 [m2 s-2]
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High-Frequency Wave Activity Anomaly K=½(u’2+v’2) Initial Date: 2009/12/10
K anomaly and U300 Anomalies Analysis (JRA-25 , 12/12-1/8)
K anomaly and U300 Anomalies Ensemble Forecast ( I.C. 12/10)
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010
Contours; Convergence of Eddy Momentum Flux by High-Frequency Variation ∂y (-u’v’) (contour interval: 2 ・ 10-4 [m s-2] )
Colors: 300-hPa Zonal Wind Anomaly [m s-1]
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Convergence of Momentum Flux ∂y (-u’v’) and U300 Initial Date: 2009/12/10∂y (-u’v’), U300 Anomaly Analysis (JRA-25 , 12/12-1/8)
∂y (-u’v’), U300 Anomaly Ensemble Forecast ( I.C. 12/10)
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010
Ensemble Perturbations
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 201032
The JMA monthly forecast system produces initial perturbations using the Bred Vectors, which is specially intended to obtain large-scale growing modes in the tropics.
Chikamoto et al. 2007, GRL
Tropical Bred Vector Perturbation
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 201033
Hovmoeller diagrams of 200-hPa velocity potential averaged over the 10S–10N region for (a) the observed field, (b) the bred vector
The space-time spectrum of the 200-hPa velocity potential of the tropical bred vector averaged over the 10S–10N region.
• Old • Singular Vector with a simplified model (NH only)
• New• Combination of BV method in the tropics and
extra-tropics (NH only).
Perturbation (500-hPa GPH Spread)
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 201034
OLD NEW NEW-OLD
Courtesy: M. Hirai@JMA
[m]
• Perturbations in tropics contribute to increase of the spread in extra-tropics.
Perturbation and Spread-Skill Relationship
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 201035
N. H. S. H.
New RMSEOld Spread
Courtesy: M. Hirai@JMA
Precipitation in June 2010
Zhejiang 174 %
Fuzhou 157 %
Based on CLIMAT reports
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 201036
Ratio to Normals
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Index of 1st Mode
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010
Wand and Fan Index : U850 (5-15N,90-130E) – U850 (22.5-32.5N,110-140E)
The 1st mode is well correlated with Wang and Fan Index (Wang and Fan ,1999).
Index of the 1st Mode
• Z500
2009/12/10
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 201038
Forecast I.C.; 2009/12/10Analysis (12/12-1/8)
• T850
2009/12/10
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 201039
Forecast I.C.; 2009/12/10Analysis (12/12-1/8)
• SLP
2009/12/10
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 201040
Forecast I.C.; 2009/12/10Analysis (12/12-1/8)