The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas...
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![Page 1: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/1.jpg)
The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability
Thomas Reichler
Scripps Institution of Oceanography
University of California San Diego
La Jolla, CA
(now at: NOAA-GFDL / Princeton University, Princeton NJ)
![Page 2: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/2.jpg)
Outline
1. Motivation and Goal
2. Methodology
3. Predictability
•temporal evolution
•horizontal distribution
•vertical structure
4. The initial condition effect and the Antarctic oscillation
5. Summary
![Page 3: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/3.jpg)
Elements of predictability
Initial conditions (ICs)
Boundary conditions (BCs)
Physical model
MEtBCICftS );,();0,(),( xxx
![Page 4: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/4.jpg)
Goal of this study Sub-seasonal (2 weeks to 2 months) predictability of the atmosphere
= IC (weather) + BC (climate) prediction problem
ICs initially very strong, but rapid decrease in timeclassical predictability range: ~ 2 weeksbeyond that: weak or zero IC influence!?
persistent features (e.g. blocking, major modes, stratosphere) periodic features (e.g. MJO)
BCs effects are weak, require long time averagingrecent studies: mostly seasonal and longer, impacts of ENSOsub-seasonal range: relatively short averaging period
ocean & land tropics & extratropics
![Page 5: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/5.jpg)
Outline
1. Motivation and Background
2. Methodology
3. Predictability
• temporal evolution
• spatial distribution
• vertical structure
4. The initial condition effect and the Antarctic oscillation
5. Summary
![Page 6: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/6.jpg)
Experimental Design
AGCM with prescribed SSTs Different “qualities” of ICs and BCs, find out how important they are
Base runs • observed (2x) or climatological SST• continuously over many years• to produce ICs for subsequent experiments
Experiments• branching off from base runs• 107 days: DJFM and JJAS (start on the 15th)• 10-20 members, from perturbed ICs (breeding) • 22 years (1979-2000)• different combinations of ICs and BCs
![Page 7: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/7.jpg)
Experiments
•
BC IC BC’ IC’ i ME
ICBC
iBC
BC 0
IC 0
CC 0 0
ICBC-r
rean 0 0
• experiments
MECIICCBBCf
MEICtBCftS
i ;;
);0,();,(),(
xxx
(IC’=0: initial conditions from base run with BC’=0)
![Page 8: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/8.jpg)
Verification Strategy
verification 10-member ensemble-mean of experiment against 1 member of “observation”
“observation” a. one realization of ICBC (perfect model skill) repeat 20 times and average
no model errors > upper limit of predictability
(this is what I mostly show)
b. NCEP reanalysis (real world skill)
measure of skill correlation of geopotential
spatial or temporal (year-to-year)
![Page 9: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/9.jpg)
The Model
• NCEP seasonal forecasting model (e.g. Kanamitsu et al. 2002)
• originates from MRF, similar to reanalysis-2 model
• T42 (300km) L28
• RAS Convection: Moorthi and Suarez (1992)
• SW: Chow (1992)
• LW: Chow & Suarez (1994)
• Clouds: Slingo (1987)
• Gravity wave drag: Alpert et al. (1988)
• 2-layer soil model: Pan & Mahrt (1987)
• Orography: smoothed
• Ozone: zonal mean climatology
10
18
extratropical tropopause
![Page 10: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/10.jpg)
Outline
1. Motivation and Background
2. Methodology
3. Predictability
• temporal evolution
• spatial distribution
• vertical structure
4. The initial condition effect and the Antarctic oscillation
5. Summary
![Page 11: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/11.jpg)
Classical predictabilityevolution of spatial AC for global Z500 during DJFM
CC vs. CC (IC’=0, BC’=0)co
rre
latio
n
lead time (days) lead time (days)
corr
ela
tion
![Page 12: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/12.jpg)
Effects of IC’
initial condition effect has very long time scale anomalous initial conditions (IC’) lead to prolonged predictability possible reason: excitation of low-frequency modes by BC’
lead time (days)
corr
ela
tion
30 day averages
IC vs. IC
CC vs. CC
evolution of spatial AC for global Z500 during DJFM
![Page 13: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/13.jpg)
Effects of IC’ and BC’
evolution of spatial AC for NH Z500 during DJFMverified against ICBC
instantaneous 30 days 90 days
4 weeks
ICs dominate for first 4 weeks (3 weeks during ENSO, 5 weeks during neutral)
lead time (days) lead time (days) lead time (days)
corr
ela
tion
![Page 14: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/14.jpg)
Southern Hemisphere
7 weeks
evolution of spatial AC for SH Z500 during DJFMverified against ICBC
instantaneous 30 days 90 days
![Page 15: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/15.jpg)
Tropics
3 weeks
evolution of spatial AC of tropical Z200 during DJFMverified against ICBC
instantaneous 30 days 90 days
![Page 16: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/16.jpg)
DJFM
JJAS
0
5
10
15
20
25
30
35
40
45
50tim
e (
da
ys) NH
PNA
SH
TROP
Summary: Effects of IC’ and BC’
Time scale for: IC = BC
![Page 17: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/17.jpg)
Effect of model uncertainty
evolution of spatial AC of NH Z500 during DJFMICBC/ICBC vs. ICBC-r/reanalysis
90 days averages
= model error
![Page 18: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/18.jpg)
Outline
1. Motivation and Background
2. Methodology
3. Predictability
• temporal evolution
• horizontal distribution
• vertical structure
4. The initial condition effect and the Antarctic oscillation
5. Summary
![Page 19: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/19.jpg)
Horizontal structure I
ICBC
January monthly mean (week 3-6), Z500, temporal correlation
temporal correlation
Pacific South American region (PSA)
Pacific North American region (PNA)
Antarctica
Tropics
longitude
lati
tude
![Page 20: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/20.jpg)
Horizontal structure II
ICBC iBC BC IC
January monthly mean (week 3-6), Z500, temporal correlation
![Page 21: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/21.jpg)
Effects of persistencepersistence Z500 (Jan)
ICBC
IC
predictability Z500 (Jan)
ICBC
IC
persistent boundary forcing
atmospheric persistence
ICBC
major modes Z500 (JFM)
AAO
SO
NAO
PNA
NA
![Page 22: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/22.jpg)
Outline
1. Motivation and Background
2. Methodology
3. Predictability
• temporal evolution
• horizontal structure
• vertical structure
4. The initial condition effect and the Antarctic oscillation
5. Summary
![Page 23: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/23.jpg)
Vertical structure I
Jan Feb Mar
ICBC: temporal correlations of monthly and zonal mean geopotential
temporal correlation
latitude latitudelatitude
he
igh
t
![Page 24: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/24.jpg)
Vertical structure II
Jan Jan Feb Feb MarMar
ICBC
IC-ICBC
BC-ICBC
![Page 25: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/25.jpg)
Vertical structure III: neutral ENSO
Jan Jan Feb Feb MarMar
ICBC
IC-ICBC
BC-ICBC
![Page 26: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/26.jpg)
Outline
1. Motivation and Background
2. Methodology
3. Predictability
• temporal evolution
• spatial distribution
• vertical structure
4. The initial condition effect and the Antarctic oscillation
5. Summary
![Page 27: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/27.jpg)
Antarctic Oscillation (AAO)
ICBC-B (0.81)
EOF1 (59%)
ICBC-A
IC (0.80)
BC (0.10)
January, Z500
![Page 28: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/28.jpg)
AAO index (Jan 1) and forecast skill (Jan)
AAO index (Jan 1)
El Nino
La Nina
ICBC (0.53)
iBC (0.05) BC (-0.15)
spatial AC for SH Z500 during January, verified against ICBC
AAO index (Jan 1)
IC (0.75)
![Page 29: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/29.jpg)
Outline
1. Motivation and Background
2. Methodology
3. Predictability
• temporal evolution
• spatial distribution
• vertical structure
4. The initial condition effect and the Antarctic oscillation
5. Summary
![Page 30: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/30.jpg)
Summary
The effects of ICs on forecast skill• were detectable for ca. 8 week,• were more important than BCs for ca. 4 weeks,• were particularly important over Antarctica, the Tropics, and the lower stratosphere.
Regions of large skill coincided with regions of major modes.
Total skill (ICBC) can be understood as the sum of IC and BC produced skill (ICBC=BC+IC).
IC produced skill came mostly from atmospheric persistence in relationship with major modes.
Conclusion: Do not underestimate the importance of ICs for seasonal to sub-seasonal forecasts.
![Page 31: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/31.jpg)
![Page 32: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/32.jpg)
Scale variations
0-4 d0-4 d0-4 d 4-104-10 10-2010-20 20-4020-40 40-10040-100
ICBCICBC
Saturation of spectral error energy globally, Z500, DJFM
Maximum gain from ICBC
ICIC
BCBC
m (zonal)
n (total)
![Page 33: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/33.jpg)
Perfect ENSO JFM ZPerfect ENSO JFM ZJANJAN FEBFEB MARMAR
ICBCICBC
IC-IC-ICBCICBC
BC-BC-ICBCICBC
![Page 34: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/34.jpg)
Real world JFM ZReal world JFM Z
JANJAN FEBFEB MARMAR
ICBCICBC
BC-BC-ICBCICBC
![Page 35: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/35.jpg)
Perfect JAS ZPerfect JAS ZJULJUL AUGAUG SEPSEP
ICBCICBC
IC-IC-ICBCICBC
BC-BC-ICBCICBC
![Page 36: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/36.jpg)
Vertical structure II
ICBC
IC
iBC-ICBC
BC-ICBC
Jan Feb Mar
latitude latitude latitude
![Page 37: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/37.jpg)
Predictability of MJOPredictability of MJO30-70 day filtered 200 hPa velocity potential
lead time (days)
corr
ela
tion
• initial conditions are crucial
•boundary conditions are important
~ 4 weeks
![Page 38: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/38.jpg)
Real world, Z500, DJFMReal world, Z500, DJFM
30 days30 days 90 days90 days
NHNH
SHSH
= model error
verified against NCEP/NCAR reanalysis
![Page 39: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/39.jpg)
BCBC
ICIC
Temporal correlation: Z500JAN JAN
(week 3-6)(week 3-6)FEB FEB
(week 7-10)(week 7-10)MAR MAR
(week 11-14)(week 11-14)
significant IC influence
ICBCICBC
![Page 40: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/40.jpg)
BC
ICBC
IC
ICBC
Perfect world: JFM
JAN JAN FEB FEB MARMAR
Zonal mean temporal correlation: Z500
BCBC
ICIC
ICBCICBC
![Page 41: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/41.jpg)
BC
ICBC
IC
ICBC
Perfect world: JAS
JULJUL AUGAUG SEPSEP
Zonal mean temporal correlation: Z500
ICIC
BCBC
ICBCICBC
![Page 42: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/42.jpg)
BC
Real world: JFM
JAN JAN FEB FEB MAR MAR
ICBC
Zonal mean temporal correlation: Z200
BCBC
ICBCICBC
![Page 43: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/43.jpg)
JANFEB
MAR
-0.2
0
0.2
0.4
0.6
0.8
corr
elat
ion
AAO JFM H500 pr9 EM
ICBC
IC
BC
BC1
AAO, JFM, perfectAAO, JFM, perfect
![Page 44: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/44.jpg)
JANFEB
MAR
-0.2
0
0.2
0.4
0.6
0.8co
rrel
atio
n
AAO JFM H500 rean2 EM
ICBC
IC
BC
BC1
AAO, JFM, realAAO, JFM, real
![Page 45: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/45.jpg)
JULAUG
SEP
-0.2
0
0.2
0.4
0.6
0.8co
rrel
atio
n
AAO JAS H500 pr33 EM
ICBC
IC
BC
BC1
AAO, JAS, perfectAAO, JAS, perfect
![Page 46: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/46.jpg)
JANFEB
MAR
-0.2
0
0.2
0.4
0.6
0.8co
rrel
atio
n
AO JFM H1000 pr9 EM
ICBC
IC
BC
BC1
AO, JFM, perfectAO, JFM, perfect
![Page 47: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/47.jpg)
JANFEB
MAR
-0.2
0
0.2
0.4
0.6
0.8
corr
elat
ion
AO JFM H1000 rean2 EM
ICBC
IC
BC
BC1
AO, JFM, realAO, JFM, real
![Page 48: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/48.jpg)
JULAUG
SEP
-0.2
0
0.2
0.4
0.6
0.8co
rrel
atio
n
AO JAS H1000 pr33 EM
ICBC
IC
BC
BC1
AO, JAS, perfectAO, JAS, perfect
![Page 49: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/49.jpg)
OutlineOutline
I. Introduction
II. Experimental Design
III. Results
a. Time evolution of skill and scale variations
b. Regional variations and vertical structure
c. Antarctic oscillation
d. Tropical predictability
IV. Summary
![Page 50: The Role of Initial and Boundary Conditions for Sub-Seasonal Atmospheric Predictability Thomas Reichler Scripps Institution of Oceanography University.](https://reader030.fdocuments.in/reader030/viewer/2022032521/56649d565503460f94a34736/html5/thumbnails/50.jpg)
U850 (10N-10S)U850 (10N-10S)
time (d)
0
107
Atl Ind W Pac Atl Atl Ind W Pac Atl Atl Ind W Pac Atl
temporal correlation
ICBCICBC ICIC BC-ICBCBC-ICBC