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Transcript of 1 Planetary Wave-Induced Ozone Heating and its Effect on Troposphere-Stratosphere Communication...
1
Planetary Wave-Induced Ozone Heating and itsEffect on Troposphere-Stratosphere Communication
Terry NathanAtmospheric Science ProgramUniversity of California, Davis
Eugene CorderoDepartment of MeteorologySan Jose State University
John AlbersAtmospheric Science ProgramUniversity of California, Davis
OUTLINE
Motivation / Goal
Model and Equations
Conceptual Framework
“New” Pathway for Communication
Ozone-Modified “Downward Control”
Ozone-Modified Wave-Mean Flow Interaction
Conclusions
2
Motivation / Goal
Motivation
Goal
Stratosphere-troposphere communication is an integral part of the climate system. Essential to this communication is a faithful representation of the interactions between dynamics, radiation and chemistry in the stratosphere.
Yet it remains unclear how natural and human-caused changes in these interactions are communicated to the troposphere.
To determine to what extent planetary wave-induced ozone heating serves as a feedback mechanism eedback mechanism and pathway fpathway for amplifying and communicating natural and human-caused changes in stratospheric ozone to the troposphere.
3
Wave-Induced Ozone Heating StudiesStudy Wave Type Remarks
Leovy (1966) inertio-gravity waveradiative-photochemical destabilization of inertio-gravity waves near the mesopause
Lindzen (1966) baroclinic waveradiative-photochemical destabilization of a baroclinic zonal current to baroclinic waves in the mesosphere (2-level model)
Zhu and Holton (1986, JAS) inertio-gravity wavesignificant radiative-photochemical damping of inertio-gravity waves in the stratosphere and lower to mid mesosphere
Nathan (1989, JAS) free Rossby waveanalytical study showing how wave-induced ozone heating can alter the damping rates of free Rossby waves
Nathan and Li (1991, JAS) free Rossby wavenumerical study showing how wave-induced ozone heating can alter the damping rates of free Rossby waves
Nathan et al. (1994, GRL) free Rossby wavewave-induced ozone heating destabilizes traveling waves during summer
Echols and Nathan (1996, JAS) Kelvin wavewave-induced ozone heating modifies the wave fluxes that drive the semi-annual oscillation
Cordero and Nathan (2000, JAS)Kelvin and Rossby-gravity
waves wave-induced ozone heating modifies the wave fluxes that drive the quasi-biennial oscillation
Xu, Smith, Brasseur (2001) inertio-gravity waveconfirmed Leovy’s (1966) study using a more sophisticated radiative-photochemical model
Cordero and Nathan (2005, GRL)Kelvin and Rossby-gravity
waves
wave-induced ozone heating provides a pathway for communicating the effects of solar variability to the quasi-biennial oscillation
Nathan and Cordero (2007; JGR) forced Rossby wavederivation of a refractive index for vertically propagating planetary waves that accounts for wave-induced ozone heating
Gabriel et al. (2007; GRL) GCM MEACHAM5“… important influence of ozone-dynamics interaction…” “…shift of upward and eastward directed stationary wave train…”
4
Model(Nathan and Li 1991, JAS; Cordero and Nathan 2007, JGR)
Dynamics Radiative-Photochemical
Quasigeostrophic
Bottom forcing
Linear mechanistic
Analytical (WKB)
Wave-Mean Flow Interaction
Mechanistic: Holton-Mass (1976) with ozone transport and photochemistry
Newtonian Cooling
Ozone transport
Ozone photochemistry
Solar spectral irradiance accounted for in ozone production / destruction
Catalytic loss processes involving hydrogen, nitrogen and chlorine compounds are parameterized by adjusting pure oxygen reaction rate (Hartman 1978)
Ozone shielding effect
5
Governing Equations
1
Qz
c
xq
xu
t e
Fyy
Q
z
c
z
u
z
u
z
c
t
u RT
1
L
2
21
2
z RR dQ
0
21
)(
Perturbation Equations Zonal-Mean Equations
zR
HfdS T
z
'
')(
' 0
021
z
HfdQ T
z
'
')(
' 00
21
Swz
vyz
wy
vt
1
Sz
wyxx
ut
z RTRR TTdS
0
21
)(
HEATING/COOLING
PRODUCTION/DESTRUCTION
OZONE
QGPVE ZONAL MEAN FLOW
Plus Mean-Meridional Circulation Equation
6
m2<0
m2=0
022
2
Amdz
Ad
...),,,;( 3OTuzm
m2>0
EVANESCENT
PROPAGATING REGION
= Complex Refractive
Index*
Conceptual Framework
REFLECTING SURFACE
* Nathan, T. R., and E. C. Cordero, 2007: An ozone-modified refractive index for vertically propagating planetary waves. J. Geophysical Research - Atmospheres, 112, D02105, doi:10.1029/2006JD007357. Cordero, E., and T. R. Nathan, 2005: A new pathway for communicating the 11-year solar cycle
signal to the QBO. Geophys. Res. Lett., 32, No. 18, L18805, 10.1029/2005GL023696.
Re (m) ~ propagation
Im (m) ~ attenuation
7CIRCULATION AND CLIMATE
(MEAN FIELDS)REFRACTIVE INDEX
PWD
TU ,',',',','3 TwvuO
(WAVE FIELDS)
REFRACTIVE INDEXPWD
“TRADITIONAL” PATHWAY
INCOMPLETE VIEWZonal-Mean Pathway
“NEW” PATHWAY
MORE COMPLETE VIEWWave-Ozone Pathway
plus Zonal-Mean Pathway
3O
ExternalForcing
(e.g., solarCFCs etc)
“New” Pathway for Ozone-Modulated Troposphere-Stratosphere Communication
8
Wave-Ozone Pathway
The planetary wave-induced
ozone heating (wave-ozone
feedback process) pivots on
wave-like perturbations in the
wind and temperature fields
producing wave-like
perturbations in the ozone field. ',',',' TwvuVertically
Propagating Wave
'3O
Wave Perturbation in Ozone
9
The phasing and structure of the
wind, temperature and ozone fields --
which are coupled to each other as
well as to the background
distributions of wind, temperature
and ozone -- directly affect wave
transience and wave dissipation,
processes vital to the driving of the
zonal-mean circulation.
Any perturbation to the wave-ozone feedbacks, natural or human-caused,
will be imparted to the zonal-mean field.
PHASE DIFFERENCE
T’
O’
10
Ozone-Modified Downward Control
Adapted from Holton 2004
z
dzXfy
w ')(* 01
01
0 F
Residual Vertical Velocity“Downward Control”
To what extent is the divergence of Eliassen-Palm flux (i.e., PWD) affected by the planetary wave induced ozone heating?
F
“Downward influence from a radiative perturbation can only arise through changes in reflection and meridional propagation of planetary waves.”
Shepard and Shaw (2004; JAS)
11
WKB Solution for EP-Flux Divergence
cclyikxdZZmiZBZAZZ
Z
sin)exp(')'(exp)](),([)](ˆ),(ˆ[
0
z
iri dmAmm0
2 '2exp|| F
nAttenuatio
i
nPropagatio
r ZmiZmZm )()()( Ozone-Modified Vertical Wavenumber (Refractive Index)
Ozone-Modified Planetary Wave Drag
12
Ozone-Modified Propagation and Attenuation
advectionozoneMeridional
r
advectionozoneVertical
NC
r ykufHM
zHfkuHmZm
21
01
0T0 2
Γ1
2
1)(
“CLASSIC” REFRACTIVE INDEX
LOWER STRATOSPHERE – DYNAMICAL CONTROL
AdvectionOzoneMeridional
advectionozoneVertical
NC
Ti
i ykumHfzHfku
MmZm
20
12
01
00 2
)(
UPPER STRATOSPHERE – PHOTOCHEMICAL CONTROL
CoolingcalPhotochemi
T
NC
Tr
r Rku
MmZm
110)(
CoolingcalPhotochemi
T
NC
Ti
i Hfku
MmZm
11
00)(
13
Results
*w *w0*w 0*w
SOUTH NORTH
Zonal Wave 2Zonal Wave 2
Based on climatological distributions of wind, temperature and ozone (winter).
No Ozone
With Ozone
Normalized Vertical Structure of Latitude-Height Cross-Section of *w
Reflecting Surface
*w
smm /10 210-15% decrease in troposphere
Factor of 2 increasein stratosphere
14
Holton-Mass Model with Wave-Induced Ozone Heating
Holton and Mass (1976) -- No Ozone FeedbacksCurrent Study – With Ozone Feedbacks
Mea
n Z
on
al W
ind
(m
s−
1) @
z=
15 k
mM
ean
Zo
nal
Win
d (
m s
−1)
@ z
=50
km
Mea
n Z
on
al W
ind
(m
s−
1) @
z=
15 k
mM
ean
Zo
nal
Win
d (
m s
−1)
@ z
=50
km
Holton and Mass (1976) -- No Ozone FeedbacksCurrent Study – With Ozone Feedbacks
Holton and Mass (1976) -- No Ozone FeedbacksCurrent Study – With Ozone Feedbacks
Holton and Mass (1976) -- No Ozone FeedbacksCurrent Study – With Ozone Feedbacks
Time (days)
Time (days) Time (days)
Time (days)
Wave 2, hb= 270 m Wave 1, hb= 50 m
15
Conclusions
The combined effects of planetary wave-induced ozone
heating, “downward control,” and wave reflection may communicate – and amplify – both natural and human-caused
perturbations in stratospheric ozone to the troposphere.
A more complete pathway
for communicating solar cycle-induced changes in
stratospheric ozone to the climate system is proposed. The pathway incorporates the effects of planetary wave- induced ozone heating.
ExternalOzone
Forcing
16
Sun-ClimateFocused Science Team
TEAM MEMBERS
Terry NathanEugene Cordero
Linton FloydRolando Garcia
Lon HoodCharles Jackman
Judith LeanJohn McCormack
Jeff MorrillCora RandallDavid Rind
Sponsored by NASA’s Living with a Star ProgramSponsored by NASA’s Living with a Star Program
“SENSITIVITY of REGIONAL and GLOBAL CLIMATE to SOLAR FORCING”
http://sun-climate.lawr.ucdavis.edu/