hemispheric differences in tropical lower … · hemispheric differences in tropical lower...
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HemisphericDifferencesinTropicalLowerStratosphericTransportandTracersAnnualCycle
A11U:ProcessesandLinkagesintheUpperTroposphereandLower
Stratosphere:ObservaDonsandModelsI
OlgaTweedy1,D.Waugh1,R.Stolarski1,2,L.Oman2
1.JohnsHopkinsUniversity,DepartmentofEarthandPlanetarySciences;2.NASAGoddardSpaceFlightCenter
AGUFallMee2ng2016https://ntrs.nasa.gov/search.jsp?R=20160014924 2018-08-21T12:52:22+00:00Z
Transport:Ver2caladvec2onvsquasi-horizontalmixing
• Randeletal.[2007]:largeseasonalcycleinupwellingisaresponseforseasonalchangesinozone.
• Abalosetal.[2012,2013]andPloegeretal.[2012]showtheimportanceofeddymixing
Thebalancebetweenupwellingandquasi-horizontalmixinginthetropicallowerstratosphereisnotwellunderstood!
TherestudieshavefocusedonvariaDonsintracersandprocessesinthetropic-wideaverage(20oN-20oS),i.e.haveconsidered“well-mixed”tropics.
OlgaTweedy Introduc2onData ResultsConclusions
Southerntropics(ST)aredifferentfromNortherntropics(NT)
• LargerannualamplitudeinNT.• 2-3monthshiainphase.
Hemisphericdifferencesinozoneannualcycle
Annualcycleamplitudeofozone(%relaDvetothemean)fromsatelliteobservaDons
MLS-v3
10
10
20
20
20 30
40S 20S EQ 20N 40N10
15
20
25
MLS-v4
10
20
20 30
30 30
40
40S 20S EQ 20N 40N
OMPS
1010
20
20 20
3030
40
40S 20S EQ 20N 40N
SAGEII
10
20
20
30
3040
40S 20S EQ 20N 40N
200
100
50
Altit
ude
(km
)
Pres
sure
(hPa
)
OlgaTweedy Introduc2onData ResultsConclusions
[Stolarskietal.,2014]
MAINQUESTIONS
1. DoChemistryClimateModels(CCMs)capturetheobserveddifferencesbetweentheNTandST?
2. WhatprocessescontroltheSTandNTannualcyclesinthemodels?
OlgaTweedy Introduc2onData ResultsConclusions
CCMVal-2MODELS
ModelSimula2ons:1960to2010simulaDonofthemodelsfromCCMVal-2mulD-modelintercomparisonprojectv 18CCMs:alltransient(historical)runswithnearlyidenDcalforcings
(GHGs,ODSs,ect).Satelliteobserva2ons:v Version3and4oftheAuraMicrowaveLimbSounder(MLS)[Liveseyet
al.,2008]v theOzoneMappingandProleSuite(OMPS)onboardNASA/NOAA
Suomi-NPPsatellite[Kramarovaetal.,2014]v theStratosphericAerosolandGasExperimentII(SAGEII)[Wangetal.,
2002]
OlgaTweedy Introduc2onData ResultsConclusions
La2tude-pressurevaria2onsinozoneseasonality
GEOSCCM
10
20
20
30 40
50
40S 20S EQ 20N 40N
WACCM
10
20
20
3030
30
4040
50
40S 20S EQ 20N 40N
UMETRAC
10
10
20
20
30
30
40
40
50
5060
40S 20S EQ 20N 40N
AMTRAC3
10
10
20
20
30
30
4050
40S 20S EQ 20N 40N
200
100
50
Latitude Latitude
Pressu
re (hP
a)
200
100
50
Pressu
re (hP
a)
200
100
50
Pressu
re (hP
a)
200
100
50
Pressu
re (hP
a)
MLS-v4
10
20
20 30
30 30
40
40S 20S EQ 20N 40N
OMPS
1010
20
20 20
3030
40
40S 20S EQ 20N 40N
200
100
50
Pressu
re (hP
a)
200
100
50
Pressu
re (hP
a)
Latitude
10
15
20
25
Altitu
de (k
m)
10
15
20
25
Altitu
de (k
m)
ULAQ
10
20
20
30
30
40
40
50
506060
MRI
10
10
20
20
30 30 40
40S 20S EQ 20N 40N Latitude 40S 20S EQ 20N 40N Latitude
200
100
50
Pressu
re (hP
a)
200
100
50Pre
ssure
(hPa)
GEOSCCM
10
20
20
30 40
50
40S 20S EQ 20N 40N
WACCM
10
20
20
30
30
30
40
40
50
40S 20S EQ 20N 40N
UMETRAC
10
10
20
20
30
30
40
40
50
5060
40S 20S EQ 20N 40N
AMTRAC3
10
10
20
20
30
30
4050
40S 20S EQ 20N 40N
200
100
50
Latitude Latitude
Pressu
re (hP
a)
200
100
50
Pressu
re (hP
a)
200
100
50
Pressu
re (hP
a)
200
100
50
Pressu
re (hP
a)
MLS-v4
10
20
20 30
30 30
40
40S 20S EQ 20N 40N
OMPS
1010
20
20 20
3030
40
40S 20S EQ 20N 40N
200
100
50
Pressu
re (hP
a)
200
100
50
Pressu
re (hP
a)
Latitude
10
15
20
25
Altitu
de (k
m)
10
15
20
25
Altitu
de (k
m)
ULAQ
10
20
20
30
30
40
40
50
506060
MRI
10
10
20
20
30 30 40
40S 20S EQ 20N 40N Latitude 40S 20S EQ 20N 40N Latitude
200
100
50
Pressu
re (hP
a)
200
100
50
Pressu
re (hP
a)
GEOSCCM
10
20
20
30 40
50
40S 20S EQ 20N 40N
WACCM
10
20
20
30
30
3040
40
50
40S 20S EQ 20N 40N
UMETRAC
10
10
20
20
30
30
40
40
50
5060
40S 20S EQ 20N 40N
AMTRAC3
10
10
20
20
30
30
4050
40S 20S EQ 20N 40N
200
100
50
Latitude Latitude
Pressu
re (hP
a)
200
100
50
Pressu
re (hP
a)
200
100
50
Pressu
re (hP
a)200
100
50
Pressu
re (hP
a)
MLS-v4
10
20
20 30
30 30
40
40S 20S EQ 20N 40N
OMPS
1010
20
20 20
3030
40
40S 20S EQ 20N 40N
200
100
50Pre
ssure
(hPa)
200
100
50
Pressu
re (hP
a)
Latitude
10
15
20
25
Altitu
de (k
m)
10
15
20
25
Altitu
de (k
m)
ULAQ
10
20
20
30
30
40
40
50
506060
MRI
10
10
20
20
30 30 40
40S 20S EQ 20N 40N Latitude 40S 20S EQ 20N 40N Latitude
200
100
50
Pressu
re (hP
a)
200
100
50
Pressu
re (hP
a)
GEOSCCM
10
20
20
30 40
50
40S 20S EQ 20N 40N
WACCM
10
20
20
30
30
30
40
40
50
40S 20S EQ 20N 40N
UMETRAC
10
10
20
20
30
30
40
40
50
5060
40S 20S EQ 20N 40N
AMTRAC3
10
10
20
20
30
30
4050
40S 20S EQ 20N 40N
200
100
50
Latitude Latitude
Pressu
re (hP
a)
200
100
50
Pressu
re (hP
a)
200
100
50
Pressu
re (hP
a)
200
100
50
Pressu
re (hP
a)
MLS-v4
10
20
20 30
30 30
40
40S 20S EQ 20N 40N
OMPS
1010
20
20 20
3030
40
40S 20S EQ 20N 40N
200
100
50
Pressu
re (hP
a)200
100
50
Pressu
re (hP
a)
Latitude
10
15
20
25Alt
itude
(km)
10
15
20
25
Altitu
de (k
m)
ULAQ
10
20
20
30
30
40
40
50
506060
MRI
10
10
20
20
30 30 40
40S 20S EQ 20N 40N Latitude
40S 20S EQ 20N 40N
200
100
50
Pressu
re (hP
a)
200
100
50
Pressu
re (hP
a)
GEOSCCM
10
20
20
30 40
50
40S 20S EQ 20N 40N
WACCM
10
20
20
30
30
30
40
40
50
40S 20S EQ 20N 40N
UMETRAC
10
10
20
20
30
30
40
40
50
5060
40S 20S EQ 20N 40N
AMTRAC3
10
10
20
20
30
30
4050
40S 20S EQ 20N 40N
200
100
50
Latitude Latitude
Pressu
re (hP
a)
200
100
50
Pressu
re (hP
a)
200
100
50
Pressu
re (hP
a)
200
100
50
Pressu
re (hP
a)
MLS-v4
10
20
20 30
30 30
40
40S 20S EQ 20N 40N
OMPS
1010
20
20 20
3030
40
40S 20S EQ 20N 40N
200
100
50
Pressu
re (hP
a)200
100
50
Pressu
re (hP
a)
Latitude
10
15
20
25
Altit
ude (
km)
10
15
20
25
Altit
ude (
km)
ULAQ
10
20
20
30
30
40
40
50
506060
MRI
10
10
20
20
30 30 40
40S 20S EQ 20N 40N Latitude
40S 20S EQ 20N 40N
200
100
50
Pressu
re (hP
a)
200
100
50
Pressu
re (hP
a)
ObservaDonsModels
GEOSCCM
10
20
2030 40
50
40S 20S EQ 20N 40N
WACCM
10
20
20
30
30
3040
40
50
40S 20S EQ 20N 40N
UMETRAC
10
10
20
20
30
30
40
40
50
5060
40S 20S EQ 20N 40N
AMTRAC3
10
10
20
20
30
30
4050
40S 20S EQ 20N 40N
200
100
50
Latitude Latitude
Pressu
re (hP
a)
200
100
50
Pressu
re (hP
a)
200
100
50
Pressu
re (hP
a)200
100
50
Pressu
re (hP
a)
MLS-v4
10
20
20 30
30 30
40
40S 20S EQ 20N 40N
OMPS
1010
20
20 20
3030
40
40S 20S EQ 20N 40N
200
100
50
Pressu
re (hP
a)
200
100
50
Pressu
re (hP
a)
Latitude
10
15
20
25
Altit
ude (
km)
10
15
20
25
Altit
ude (
km)
ULAQ
10
20
20
30
30
40
40
50
506060
MRI
10
10
20
20
30 30 40
40S 20S EQ 20N 40N Latitude
40S 20S EQ 20N 40N
200
100
50
Pressu
re (hP
a)
200
100
50
Pressu
re (hP
a)
OlgaTweedy Introduc2onData ResultsConclusions
MULTI-MODELCOMPARISON
• Distinguished between NT (0-20oN) and ST (0-20oS)
• In most of CCMVal-2 models
NT amplitude > ST amplitude.
• Large spread in amplitudes
among models. 0.0 0.05 0.10 0.15 0.20ST Amplitude O3 (ppmv)
0.00
0.05
0.10
0.15
0.20
NT Am
plitud
e O3 (
ppmv
)
0.0 0.1 0.2 0.3 0.4 0.5 0.6ST Amplitude w* (mm/s)
0.00.10.20.30.40.50.6
NT Am
plitud
e w* (
mm/s)
0.0 0.1 0.2 0.3 0.4 0.5 0.6ST Amplitude w* (mm/s)
0.00
0.05
0.10
0.15
0.20
ST Am
plitud
e O3 (
ppmv
)
0.0 0.1 0.2 0.3 0.4 0.5 0.6NT Amplitude w* (mm/s)
0.00
0.05
0.10
0.15
0.20
0.25
NT Am
plitud
e O3 (
ppmv
)
MLS-v4 OMPS
SAGEII
MERRAERA-40
ERA-INT
OlgaTweedy Introduc2onData ResultsConclusions
DoChemistryClimateModels(CCMs)capturetheobserveddifferencesbetweenNTandST?
ST:spreadinw*amplitudeamongCCMVal-2models“explains”mostofspreadinO3amplitudeConclusion:upwellingiscontrollingfactorintheST
Doesseasonalityinupwellingexplainseasonalityinozone?OlgaTweedyIntroduc2onDataandMethodsResultsConclusions
0.0 0.05 0.10 0.15 0.20ST Amplitude O3 (ppmv)
0.00
0.05
0.10
0.15
0.20
NT Am
plitud
e O3 (
ppmv
)0.0 0.1 0.2 0.3 0.4 0.5 0.6
ST Amplitude w* (mm/s)
0.00.10.20.30.40.50.6
NT Am
plitud
e w* (
mm/s)
0.0 0.1 0.2 0.3 0.4 0.5 0.6ST Amplitude w* (mm/s)
0.00
0.05
0.10
0.15
0.20
ST Am
plitud
e O3 (
ppmv
)
0.0 0.1 0.2 0.3 0.4 0.5 0.6NT Amplitude w* (mm/s)
0.00
0.05
0.10
0.15
0.20
0.25
NT Am
plitud
e O3 (
ppmv
)
MLS-v4 OMPS
SAGEII
MERRAERA-40
ERA-INT
RangeofamplitudesinO3fromobservaDonsandw*fromreanalysis
NT:norelaDonshipbetweenw*amplitudeandO3amplitudeamongCCMVal-2models.Conclusion:otherfactorsdetermineozoneseasonality(mixingmaybemoreimportant)
Doesseasonalityinupwellingexplainseasonalityinozone?OlgaTweedyIntroduc2onDataandMethodsResultsConclusions0.0 0.05 0.10 0.15 0.20
ST Amplitude O3 (ppmv)
0.00
0.05
0.10
0.15
0.20
NT Am
plitud
e O3 (
ppmv
)
0.0 0.1 0.2 0.3 0.4 0.5 0.6ST Amplitude w* (mm/s)
0.00.10.20.30.40.50.6
NT Am
plitud
e w* (
mm/s)
0.0 0.1 0.2 0.3 0.4 0.5 0.6ST Amplitude w* (mm/s)
0.00
0.05
0.10
0.15
0.20
ST Am
plitud
e O3 (
ppmv
)
0.0 0.1 0.2 0.3 0.4 0.5 0.6NT Amplitude w* (mm/s)
0.00
0.05
0.10
0.15
0.20
0.25
NT Am
plitud
e O3 (
ppmv
)
MLS-v4 OMPS
SAGEII
MERRAERA-40
ERA-INT
Quan2fyingtransportaffectsonozoneseasonality
1. TwomodelsfromCCMVal-2project:WACCMandGEOSCCM2. DisDnguishedbetweenNT(0-18oN)andST(0-18oS)3.TransformEulerianMeananalysis(TEM)[Andrews,1987]:-toisolateroleofverDcaltransport(red),horizontaltransport(green),andchemistry(blue).
OlgaTweedy Introduc2onData ResultsConclusions
ProcessescontrollingtheNTandSTannualcycles
v NT–horizontalmixingisadominantcauseofseasonality
dO3/dt(P
pbv/day) GEOSCCM(85hPa) WACCM(86hPa)
v ST–upwellingisadominantcauseofseasonality
dO3/dt(P
pbv/day)
OlgaTweedy Introduc2onData ResultsConclusions
Zonalvaria2onsinannualcycleamplitude
v July:InflowofozonerichairfromNHextratropicsintothetropicsbyN.AmericanandAsianSummerMonsoon
v January:Ozoneismixed
intothetropicsoverAtlanDcandPacificoceansbyRossbywavebreaking
OlgaTweedy Introduc2onData ResultsConclusions
CONCLUSIONSv Paradigmofwell-mixedtropicshavetobereconsideredv ThemajorityoftheCCMsproducedtheobservedfeatureofalarger
annualcycleintheNTthanSTv ThespreadamongthemodelsmuchlargerthaninobservaDons
suggesDnglargedifferencesintransportamongthemodelsv NT-STcontrastisduetodifferencesinbalancebetweentransport
processes:v SeasonalityinupwellingismostimportantintheSTv Seasonalityinhorizontalmixing–intheNT.
OlgaTweedy Introduc2onData ResultsConclusions
ACKNOWLEDGEMENTS
ThismaterialisbaseduponworksupportedbytheNaDonalScienceFoundaDonGraduateResearchFellowshipProgram(NSFGRFP)AuthorsaregratefultoM.AbalosforprovidingthemwiththeWACCMdata
Thankyou!Ques2ons?
REFERENCES
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• Konopkaetal.(2010),Annualcycleofozoneatandabovethetropicaltropopause:ObservaDonsversussimulaDonswiththeChemicalLagrangianModeloftheStratosphere(CLaMS),Atmos.Chem.Phys.,10(1),121–132,doi:10.5194/acp-10-121-2010
• Pawson,etal.(2008),GoddardEarthObservingSystemchemistry-climatemodelsimulaDonsofstratosphericozone-temperaturecouplingbetween1950and2005,J.Geophys.Res.,113,D12103,doi:10.1029/2007JD009511.
• Stolarskietal.(2014),SeasonalvariaDonofozoneinthetropicallowerstratosphere:Southerntropicsaredifferentfromnortherntropics,J.Geophys.Res.Atmos.,119,doi:10.1002/2013JD021294
• Andrews,D.G.,Holton,J.R.,andLeovy,C.B.:MiddleAtmosphereDynamics,AcademicPress,Orlando,Florida,489pp,1987