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TESTING THE REALISM OF THE MMF (or any GCM)
REPRESENTATION OF THE MJO
William B. Rossow
Eric Tromeur
City College of New York
CMMAP Meeting 29-31 July 2008
Index based on the first extended EOF analysis of 200hPa velocity potential anomalies from equatorward of 30N
MJO Index
Chen Y. and A. D. Del Genio, Climate Dynamics, 2008
Maloney E. and D. L. Hartmann, J. Climate, 1998
Index based on the first two EOFs of the bandpass-filtered (20 - 80 days) 850hPa zonal wind averaged from 5N to 5S
every 2.5 around the equator
Wheeler M. C. and H. H. Hendon, Monthly Weather Review, 2004
Index based on the first two EOFs of the combined fields of 850hPa zonal wind, 200hPa zonal wind, and OLR data
averaged from 15N to 15S every 2.5 around the equator
Tian B., Waliser D. E., and E. J. Fetzer, GRL, 2006
Index based on the first extended EOF analysis of the bandpass-filtered (30 - 90 days) rainfall anomalies from
30N to 30S every 1 around the equator
Index based on the first extended EOF analysis of 200hPa velocity potential anomalies from equatorward of 30N
MJO Index in Tropics
MJO
ind
ex
: 1
0 c
om
po
ne
nts
National Weather Service / Climate Prediction Center
Ne
ga
tive
va
lue
s :
en
ha
nce
d c
on
vect
ion
Po
sitiv
e v
alu
es
: su
pp
ress
ed
co
nve
ctio
n
Consider a strong MJO event to be one when index < -1
Composite of cloud regimes function of MJO phase (Chen and Del Genio, 2008)
Focus on the Indo-Pacific warm pool and the boreal winter (November-April)
Ten time-lagged patterns of the first EEOF of pentad CHI200 anomalies
RFO of MJO Index in 60E - 180 E region (1983 - 2004)
Jan-Dec periods
Continuum of MJO index values
MJO signal all over the year Stronger anomalies during the Boreal Winter
ISCCP WEATHER STATES
1. Cloud Properties
2. Diabatic Heating
3. Variations of RFO and Large-Scale Circulation during MJO
PC - TAU histogram pattern and Map in Tropics over 21.5 years19
83 -
200
4 tim
e pe
riod
Ros
sow
et a
l, G
RL,
200
5
Cluster Analysis + ISCCP D1 data
WS1 : Deep cumulus clouds
WS2 : Cirrostratus Anvil clouds
WS3 : Congestus clouds
WS4 : Cirrus clouds
WS5 : Shallow cumulus clouds
WS6 : Stratocumulus clouds
Composite of precipitation in Tropics (1997 - 2004)
Composite of Radiative net fluxes in ATM in Tropics (1997 - 2004)
Shortwave net fluxLongwave net flux
Composite of Surface Fluxes in Tropics (1989 - 2000)
Latent Heat Flux Sensible Heat Flux
RFO of each cloud regime in 60E-180E region / 5S-5N latitude band
(MJO events in November-April periods from 1983 - 2004)W
eak
MJO
(in
dex
< -
1)S
tron
g M
JO (
inde
x <
-2.
2)
WS1
WS2
WS3
WS4
WS5
WS6
WS7
Convective cloud regimes
Suppressed cloud regimes
Clear sky
Cloud regimes
Cirrus regime
Peak Ratio of each cloud regime in 60E-180E region / 5S-5N latitude band
(MJO events in November-April periods from 1983 - 2004)
di = 0.1
-2.2
I1
I2 I3 I4 I5 I6
I1
I2
PR2P0
(P 3 P3)
VARIATIONS OF DIABATIC HEATING AND WINDS DURING MJO
Method 2: rfo(n,lag)*pcp(n)
Composite of Total Precipitation Anomalies in 60E-180E region / 5S-5N latitude band
(MJO events in November-April periods from 1997 - 2004)
GPCP Precipitation and cloud regimes in 60E-180E region / 5S-5N latitude band
(MJO events in November-April periods from 1997 - 2004)S
tron
g M
JO (
inde
x <
-2.
2)W
eak
MJO
(in
dex
< -
1)
Me
tho
d 2
: rf
o(n
,lag
)*p
cp(n
)
Method 2: rfo(n,lag)*srf(n)
Composite of Total Surface Flux Anomalies in 60E-180E region / 5S-5N latitude band
(MJO events in November-April periods from 1989 - 2000)
Latent Heat Flux Sensible Heat Flux
Strong MJO (index < -2.2)Weak MJO (index < -1)
Composite of Omega in Tropics (1983 - 2004)
NCEP/NCAR Reanalysis
a/ Omega at 200mb
b/ Omega at 500mb
c/ Omega at 850mb
a/
c/b/
Method 1 : om(n,lag)
Strong MJO (index < -2.2)Weak MJO (index < -1)
Method 2 : rfo(n,lag)*om(n)
Strong MJO (index < -2.2)Weak MJO (index < -1)
Composite of Omega in 60E-180E region / 5S-5N latitude band (1983 - 2004)
200 mb
500 mb
850 mb
200 mb 200 mb 200 mb
500 mb 500 mb 500 mb
850 mb 850 mb 850 mb
THE TESTS
1. Verify Large-Scale Circulation Variations √√
2. Verify Associated Changes in Cloud Property Distributions (WS – slide 14)
3. Verify Associated Variations of Diabatic Heating and Winds – Amplitude & Phase
4. Identify Key Process(es) in Model
5. Verify Behavior in Observations
THINGS TO DO
Finer Time Resolution (Lags, ITA)
Storm Size – Lifetime Distributions
Tracks and Evolution
Vertical Structure
BACKUP SLIDES
Longwave net flux
Strong MJO (index < -2.2)Weak MJO (index < -1)
Shortwave net flux
Strong MJO (index < -2.2)Weak MJO (index < -1)
Composite of Radiative net fluxes in ATM in 60E-180E region / 5S-5N latitude band
(MJO events in November-April periods from 1997 - 2004)Method 2: rfo(n,lag)*rad(n)
Latent Heat Flux
Strong MJO (index < -2.2)Weak MJO (index < -1)
Sensible Heat Flux
Strong MJO (index < -2.2)Weak MJO (index < -1)
Composite of Surface Fluxes in 60E-180E region / 5S-5N latitude band
(MJO events in November-April periods from 1989 - 2000)
Method 2: rfo(n,lag)*srf(n)
Composite of precipitation in Tropics (1997 - 2004)
Method 2 rfo(n,lag)*pcp(n)
Method 1 pcp(n,lag)
Composite of Precipitation
Cloud regimes MJO phase
No change of precip with WS
Composite of Radiative net fluxes in ATM in Tropics (1997 - 2004)
Shortwave net fluxLongwave net flux
Composite of Surface Fluxes in Tropics (1989 - 2000)
Latent Heat Flux Sensible Heat Flux
GPCP Precipitation and cloud regimes in 60E-180E region / 5S-5N latitude band
(MJO events in November-April periods from 1997 - 2004)Method 1 : pcp(n,lag) Method 2 : rfo(n,lag)*pcp(n)
Str
ong
MJO
(in
dex
< -
2.2)
Wea
k M
JO (
inde
x <
-1)
Method 1: lw(n,lag)
Strong MJO (index < -2.2)Weak MJO (index < -1)
Composite of Longwave net fluxes in ATM in 60E-180E region / 5S-5N latitude band
(MJO events in November-April periods from 1997 - 2004)
Method 2: rfo(n,lag)*lw(n)
Strong MJO (index < -2.2)Weak MJO (index < -1)
Method 1: sw(n,lag)
Strong MJO (index < -2.2)Weak MJO (index < -1)
Method 2: rfo(n,lag)*sw(n)
Strong MJO (index < -2.2)Weak MJO (index < -1)
Composite of Shortwave net fluxes in ATM in 60E-180E region / 5S-5N latitude band
(MJO events in November-April periods from 1997 - 2004)
Method 1: lhf(n,lag)
Strong MJO (index < -2.2)Weak MJO (index < -1)
Method 2: rfo(n,lag)*lhf(n)
Strong MJO (index < -2.2)Weak MJO (index < -1)
Composite of Latent Heat Fluxes in 60E-180E region / 5S-5N latitude band
(MJO events in November-April periods from 1989 - 2000)
Method 1: shf(n,lag)
Strong MJO (index < -2.2)Weak MJO (index < -1)
Method 2: rfo(n,lag)*shf(n)
Strong MJO (index < -2.2)Weak MJO (index < -1)
Composite of Sensible Heat Fluxes in 60E-180E region / 5S-5N latitude band
(MJO events in November-April periods from 1989 - 2000)
Method 1 : om(n,lag)
Strong MJO (index < -2.2)Weak MJO (index < -1)
Method 2 : rfo(n,lag)*om(n)
Strong MJO (index < -2.2)Weak MJO (index < -1)
Composite of Omega in 60E-180E region / 5S-5N latitude band (1983 - 2004)
200 mb
500 mb
850 mb
200 mb 200 mb 200 mb
500 mb 500 mb 500 mb
850 mb 850 mb 850 mb
Strong MJO (index < -2.2)Weak MJO (index < -1)
Method 2: rfo(n,lag)*lw(n)
Composite of Anomalies of Total LW net flux in 60E-180E region / 5S-5N latitude band
(MJO events in November-April periods from 1997 - 2004)
Strong MJO (index < -2.2)Weak MJO (index < -1)
Method 2: rfo(n,lag)*sw(n)
Composite of Anomalies of Total SW net flux in 60E-180E region / 5S-5N latitude band
(MJO events in November-April periods from 1997 - 2004)
RFO of each cloud regime in 60E-180E region / 5S-5N latitude band
(MJO events in November-April periods from 1983 - 2004)
Index < -2.2
Index < -1 Index < -1.4 Index < -1.8
Index < -3Index < -2.6
PR2P0
(P 3 P3)
Longwave net flux
Strong MJO (index < -2.2)Weak MJO (index < -1)
Shortwave net flux
Strong MJO (index < -2.2)Weak MJO (index < -1)
Composite of Radiative net fluxes in TOA in 60E-180E region / 5S-5N latitude band
(MJO events in November-April periods from 1997 - 2004)Method 2: rfo(n,lag)*rad(n)
