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)

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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

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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

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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

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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

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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/