Dynamical Response to the 11-Year Solar Cycle (and the QBO)

in the Middle Atmosphere

Marie Curie Outgoing International Fellowship

ISSI International Team MeetingBern, SwitzerlandApril 20, 2006

Katja Matthes 1,2

1 Freie Universität Berlin, Institut für Meteorologie, Berlin, Germany

2 National Center for Atmospheric Research, Boulder, Colorado, USA

Courtesy of Kuni Kodera (2005)

Sun

UV

Earth

Ozone T, U

Indirect Influence

Dynamical impact

trop.

Strat.

Visible

Earth

Direct Influence

Radiative impact

trop.

Strat.

Sun

?

Possible Ways for Solar Influence on Climate

Mechanism – Influence of the 11-Year Solar Cycle

Mesosphere

Change of meridionaltemperature gradient

Circulation changes(wind, waves, meridional

BD circulation)

UV radiation

StratosphereKodera and Kuroda

(2002)

Troposphere

Direct influence on temperature

Influence on ozone

QBO

SAO

Gray et al. (2001a,b)Gray et al. (2003, 2004)

Labitzke (1987), Labitzke and van Loon (1988)

Tropopause

Stratopause

Indirect influence, difficult to measure

ModelingMatthes et al.

(2004)

Ocean?

Thermosphere

??

?

Change of Hadley cell

Change of Walker circulation

Tropical responseLabitzke and van Loon (1988), Kodera (2004), Gleisner and Thejll (2003), Haigh (2003), Haigh et al. (2005), van Loon et al. (2004, 2006),

Matthes et al. (2006a)

NH polar responseKodera (2002, 2003), Ogi et al. (2004), Kuroda and Kodera (2004, 2006) SHMatthes et al.

(2006a)

Some Observational Facts

Positive Correlations Sun - Stratospheric Parameters

Labitzke (1999)

60N60S

NCEP/CPC (1980-1997)48 km

16 km60N60S

SSU/MSU4 (1979-1997)

Observed Solar Signal in TemperatureAnnual Mean

Scaife et al.

(2002)

Hood

(2004)

+2.5 K

+0.8 K

+0.25 K

SSU/MSU4 (1979-2003)

+ 0.9 K

Crooks & Gray

(2005)

ERA40 (1979-2001)

60S 60N

48 km

16 km

+ 1.75K

+ 0.5K

-1 K

+1 K

Courtesy of W. Randel (2005)

Calisesi and Matthes (2006)updated from Shindell et al. (1999)

Observed Solar Signal in OzoneAnnual Mean

Models vs. Observations - Tropics

Lee and Smith (2003)

SBUV (1979-1989)

SAGE (1984-1998)

16km

50km

21km

50km

60N60S

Observed Modulation of Polar Night Jet and Brewer-Dobson Circulation

1000Eq

‒ f v*∼ •F∇

AnomaliesEarly Winter

Kodera and Kuroda (2002)?

Confirmation of modulationduring NH winter and tropospheric influence with FUB-CMAM(Matthes et al., 2004, 2006a)

2-D chemical transport model studies

(Garcia et al., 1984; Brasseur, 1993; Huang

and Brasseur, 1993; Haigh, 1994; Fleming

et al., 1995)

GCM studies without realistic radiation and

ozone changes (e.g., Wetherald and Manabe, 1975; Balachandran and Rind,

1995; Balachandran et al., 1999; Kodera et al., 1991)

GCM studies with realistic radiation and

ozone changeswithout QBO

(Haigh, 1999; Larkin et al., 2000, Shindell et al., 1999,

2001; Rind et al., 2002; Matthes et al., 2003)

GCM studies with realistic radiation and

ozone changesand with QBO

(Matthes et al., 2004, 2006a; Palmer and Gray, 2005)

Development of Modeling Solar Influence on MA

Studies with Chemistry Climate ModelsIntercomparison within SOLARIS (Solar Influence for SPARC)

(Tourpalie et al., 2003, 2005; Rozanov et al., 2004; Egorova et al., 2005; Langematz et al., 2005; Schmidt and Brasseur, 2006; Marsh et al.,

2006; Matthes et al., 2006b)

Experimental Design

Perpetual Solar Maximum

Perpetual Solar Minimum

15 years

5-8 %

Data from Lean et al. (1997)

Irradiance changes max-min (%)

Data from Haigh (1994)

Ozone changes (%) Annual Mean

Solar cycle ozone variation

IC GISS

annual mean ozone (%)

3 10

850

0.01

100

0.1

1

60N30S 30N90S 90N060S

10

850

0.01

100

0.1

1

60N30S 30N90S 90N060SLatitude Latitude

Data from Shindell et al. (1999)

+3 %+3 %

+2.5 %

Low latitudes: good agreement in stratospheric temperature signal

High latitudes: dynamical signal very different

Annual MeanT (max-min) (K)

Matthes et al. (2003), Kodera et al. (2003)

Main result: improvement of model climatology = pre-requisite for realistic solar signal

GRIPS (GCM Reality Intercomparison Project for SPARC) Solar Intercomparison

Model Description FUB-CMAM

• Freie Universität Berlin Climate Middle Atmosphere Model (FUB-CMAM) (Langematz and Pawson, 1997; Pawson et al., 1998, Langematz et al., 2003, Matthes et al., 2004)

– T21L34 (5,6 x 5,6 ), top: 80km (mesosphere)– Ozone climatology– Based on ECHAM model family

No self-consistent QBO

=> Relaxation of the zonal mean wind in the model toward rocketsonde data from Gray et al. (2001)

Gray et al. (2004)

FUB-CMAM vs. Observations (Max-Min) – NH Winter

Nov

Dec

Jan

Feb

NCEP/CPC (1979-1998)ERA40 (1979-2001)

0.4

850

0.1

hPa

Matthes et al. (2004)

FUB-CMAM

0

80

km1000

„poleward-downward“ movement

modulation of the PNJ at high lats

stratospheric

response

tropospheric

response

update of Kodera (1995)

comparable with observations (e.g., Kodera, 1995)

Modulation of the Brewer-Dobson Circulation Correlations: - Vertical Component of EPF (60N/10 hPa)

in December and January Temperature

less wave forcing at high lats lower temperatures at high lats & higher temperatures at low lats => weaker BDC

Absolut (Min)

Matthes et al. (2006a)

Impact on Tropospheric Circulation Pattern

Kodera, in preparation (2006)

Jo Haigh will talk about stratosphere-troposphere coupling

QBO East warm, disturbed polar vortex

QBO West cold, undisturbed polar vortex

Holton and Tan (1980, 1982)

Solar Minimum Solar Maximum

warm, disturbed polar vortex

cold, undisturbed polar vortex

Labitzke (1987), Labitzke and van Loon (1988)

Observations: QBO-Solar Signal

• Importance of upper stratospheric winds on NH winter evolution: Gray et al. (2001a,b), Gray et al. (2003), observations and mechanistic model study, Gray et al. (2004), Palmer and Gray (2005), Pascoe et al. (2006) GCM study• Observed 11-year solar cycle in QBO itself: Salby and Callaghan (2000, 2006), Soukharev and Hood (2001), QBOw longer during solar max• QBO modulation confirmed with 2D model (McCormack, 2003) and GCM (Palmer and Gray, 2005)

QBO-Sun Interaction in the FUB-CMAM

10hPa north pole temperature +/-2σ

QBO east warmer confirms observations from Labitzke und van Loon as well as Gray et al.! also confirmed with Unified Model with self-consistent QBO (Palmer and Gray, 2005)

W

E

Solar Minimum

QBO west warmer

Solar Maximum°C

Matthes et al. (2004)

Model Description UKMO Stratosphere-Mesosphere Model

(SMM)• UKMO Mechanistic primitive-equation model of the middle atmosphere (SMM); Midrad radiation scheme, Rayleigh friction

• 100-0.01 hPa (16-80 km)• 5° x 5° x 2 km• constant amplitude wavenumber 1 forcing at lower boundary

• initial conditions = August• perpetual January conditions• experiments = 300 day long• 20-ensembles in each experiment

Courtesy of Lesley Gray (2005)

Polar Temperature at 24 km

Experiment A: Varying the Bottom Boundary

Experiment B: Varying the Equatorial Winds

TimePolar

Temperature

100 m 150 m

200 m 250 m

300 m 350 m

+40 ms-1 +20 ms-1

0 ms-1 -20 ms-1

-40 ms-1

Identical

Changing the

tropospheric

forcing or the

equatorial winds

alters the

timing of the

warmings

Courtesy of Lesley Gray (2005)

Easterly anomaly imposed in subtropics at 40-50km to mimic a solar minimum anomaly

Stratosphere Mesosphere Model exptTime-series of polar temperature

20-member ensemble

Timing of sudden warmings is very

variable in control runCourtesy of Lesley Gray (2005)

Variance of NP temperature at 24 km in UKMO GCM exp.

control

SAO + deep QBO

SAO-only

Pascoe, Gray and Scaife, 2006 (GRL)

Courtesy of Lesley Gray (2005)

Model Description NCAR-WACCM

• NCAR Whole Atmosphere Community Climate Model (NCAR-WACCM) (Collins et al., 2004; Sassi et al., 2005)

– 4 x 5 L66, top: 140km (thermosphere)– Interactive chemistry– Based on NCAR Community Climate Model family

No self-consistent QBORelaxation of the zonal mean wind in the model toward rocketsonde data from Gray et al. (2001) Very similar experiments as with the FUB-CMAM, perpetual solar and QBO simulations

Matthes et al. (2006b), to be submitted

WACCM Annual Mean Results - Differences

Ozone and Temperature (Max-Min): QBO East experiments

99% 95% significant

Maxima in temperature and ozone comparable to observations

+0.75K+3% +2.5%

Temperature (K) Ozone (%)

relative minimum in the middle stratosphere

+0.2K +1%

secondary maximum in the lower stratosphere

+0.5K +3%

Comparison NH Winter Response

WACCM versus FUB-CMAMDifference

•WACCM: ozone calculated interactively•FUB-CMAM: ozone prescribed

Zonal Mean Wind Differences - Models vs. Observations

ObservationsNCEP-CPC (1979-1998)FUB-CMAM

Nov

Dec

Jan

WACCM 1.9x2.5WACCM 4x5

Matthes et al. (2006b)

Matthes et al. (2004)

WACCM NH Winter Signal - Lower Stratosphere and

Troposphere

Dec T max-min (K)

Jan T max-min (K)

Eq 30N 60N30S60S

Jan omega min (hPa/s)

Jan omega max-min (hPa/s)

Eq 30N 60N30S60S

+1K

confirms recent observational study about influence on Hadley and Walker circulation from van Loon et al. (2006)!

WACCM NH Summer Signal - Lower Stratosphere and

Troposphere

May T max-min (K)

Jun T max-min (K)

Eq 30N 60N30S60S

Jun omega min (hPa/s)

Jun omega max-min (hPa/s)

Eq 30N 60N30S60S

first model results that confirm observational study about influence on Hadley and Walker circulation from e.g., van Loon et al. (2004), Kodera(2004)

+0.5K

4˚x 5˚SMIN

1.9˚x 2.5˚SMIN

Jul Sep Nov Jan Mar MayJul Sep Nov Jan Mar May

T90N @ 10hPa U60N @ 10hPa

Jul Sep Nov Jan Mar MayJul Sep Nov Jan Mar May

WACCM - Impact of Different Horizontal Resolution

more SSWs!

Summary• Direct 11-year solar signal in the upper stratosphere

leads to modulation of PNJ and BDC that induce indirect circulation changes in the lower stratosphere (Matthes et al., 2004) and down to the troposphere at polar and equatorial latitudes (Matthes et al., 2006a)• Solar cycle and QBO both have anomalies in the subtropical upper stratosphere that can reinforce each other and determine the timing of stratospheric sudden warmings - a frequency modulation (Gray et al., 2003, 2004; Matthes et al., 2004; Salby and Callaghan, 2006)• Results obtained with the FUB-CMAM are confirmed with more complex interactive WACCM model (Matthes et al., 2006b)

• WACCM shows for the first time lower stratospheric temperature signal in Dec/Jan and during summer (modulation of the BDC)!• Prescribed QBO in FUB-CMAM and WACCM is necessary for a more realistic solar signal

• vertical structure of temperature and ozone signal captured for the first time in CCM (WACCM)

• finer horizontal resolution represents interannual variability better and is needed for better wave-mean flow interactions

Outlook

• 110-years time varying solar cycle with and without time varying QBO • intercomparison of recent solar experiments with CCMs within SOLARIS (SPARC initiative)• intercomparison of prescribed versus self- consistent QBO

Thank you to Karin Labitzke Ulrich Cubasch

Ulrike Langematz (FU Berlin) Kunihiko Kodera

Yuhji Kuroda (MRI, Japan) Lesley Gray (Reading University, UK)

WACCM group (Byron Boville, Rolando Garcia, Fabrizio Sassi, Dan Marsh, Doug Kinnison, Stacy Walters)

(NCAR, USA) Anne Smith (NCAR, USA)