ISSI International Team Meeting
Bern, Switzerland
April 20, 2006
Dynamical Response to the 11-Year
Solar Cycle (and the QBO) in the
Middle Atmosphere
Katja Matthes 1,2
1 Freie
Universität Berlin, Institut für Meteorologie, Berlin, Germany
Center for Atmospheric Research, Boulder, Colorado, USA
2 National
Marie Curie Outgoing
International Fellowship
Possible Ways for Solar Influence on Climate
Sun
Sun
Visible
UV
Ozone
Radiative
impact
Earth
Direct Influence
T, U
Strat.
Strat.
trop.
trop.
Dynamical
impact
?
Earth
Indirect Influence
Courtesy of Kuni Kodera (2005)
Thermosphere
Mesosphere
UV radiation
Mechanism – Influence
of the 11-Year Solar Cycle
Direct influence
on temperature
Stratopause
Influence on
ozone
Stratosphere
SAO
Change of meridional
temperature gradient
Gray et al. (2001a,b)
Gray et al. (2003, 2004)
Kodera and Kuroda (2002)
Circulation changes
(wind, waves, meridional
BD circulation)
Labitzke (1987), Labitzke and van Loon (1988)
QBO
?
Tropopause
Troposphere
?
Ocean
?
Change
of Hadley cell
Change
of Walker circulation
Tropical response
Labitzke 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)
Modeling
Matthes et al. (2004)
Indirect influence,
difficult to measure
NH polar response
?
Kodera (2002, 2003), Ogi
et al. (2004), Kuroda and
Kodera (2004, 2006) SH
Matthes et al. (2006a)
Some Observational Facts
Positive Correlations Sun - Stratospheric
Parameters
Labitzke
(1999)
Observed Solar Signal in Temperature
Annual Mean
48 km
NCEP/CPC (1980-1997)
+0.8 K
-1 K
16 km
+1 K
+0.25 K
Crooks & Gray (2005)
60N 60S
60N
SSU/MSU4 (1979-2003)
48 km ERA40 (1979-2001)
+ 1.75K
+ 0.9 K
16 km
60S
+ 0.5K
60N
Courtesy of W. Randel (2005)
60S
Scaife et al. (2002)
Hood (2004)
+2.5 K
SSU/MSU4 (1979-1997)
Observed Solar Signal in Ozone
Annual Mean
50km
SBUV (1979-1989)
Models vs. Observations - Tropics
16km
60S
50km
Calisesi and Matthes (2006)
updated from Shindell et al. (1999)
60N
SAGE (1984-1998)
21km
Lee and Smith (2003)
Observed Modulation of Polar Night Jet and Brewer-Dobson
Circulation
Anomalies
Early Winter
Confirmation of modulation
during NH winter and
tropospheric influence with
FUB-CMAM
(Matthes et al., 2004, 2006a)
‒ f v*∼ ∇•F
?
1000
Eq
Kodera and Kuroda (2002)
Development of Modeling Solar Influence on MA
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 changes
without QBO
(Haigh, 1999; Larkin et al., 2000, Shindell
et al., 1999, 2001; Rind et al., 2002;
Matthes et al., 2003)
2-D chemical transport
model studies
(Garcia et al., 1984; Brasseur, 1993; Huang
and Brasseur, 1993; Haigh, 1994; Fleming
et al., 1995)
GCM studies with realistic
radiation and ozone changes
and with QBO
(Matthes et al., 2004, 2006a; Palmer and
Gray, 2005)
Studies with Chemistry Climate Models
Intercomparison 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
15 years
Perpetual Solar Minimum
Ozone changes (%) Annual Mean
Irradiance changes max-min (%)
+3 %
Data from
Haigh (1994)
Solar cycle ozone variation
annual mean ozone (%)
5-8 %
IC
GISS
0.01
0.01
0.1
0.1
1
1
Data 10from Lean et al. (1997)
3
+2.5 %
10
Data from
Shindell et al.
(1999)
100
100
850
90S
+3 %
60S
30S
0
Latitude
30N
60N
90N
850
90S
60S
30S
0
Latitude
30N
60N
90N
GRIPS (GCM Reality Intercomparison Project for
SPARC) Solar Intercomparison
Annual Mean
T (max-min) (K)
Low latitudes: good
agreement in stratospheric
temperature signal
 High latitudes: dynamical
signal very different

Main result: improvement of
model climatology = prerequisite for realistic solar
signal
Matthes et al. (2003), Kodera et al. (2003)
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)
FUB-CMAM vs. Observations (Max-Min) – NH Winter
NCEP/CPC (1979-1998)
ERA40 (1979-2001)
FUB-CMAM
Nov
„poleward-downward“
movement
 modulation of the
PNJ at high lats
 comparable with
observations (e.g.,
Kodera, 1995)

Dec
Jan
0.4
hPa
850
update of Kodera (1995)
Feb
0.1
80
1000
Gray et al. (2004)
km
Matthes et al. (2004)
0
Modulation of the Brewer-Dobson Circulation
Correlations: - Vertical Component of EPF (60N/10 hPa)
in December and January Temperature
Absolut (Min)
 less wave forcing at high lats
 lower temperatures at high lats & higher
temperatures at low lats => weaker BDC
Matthes et al. (2006a)
Impact on Tropospheric Circulation
Pattern
Kodera, in preparation (2006)
 Jo Haigh will talk about stratosphere-troposphere coupling
Observations: QBO-Solar Signal
Solar Minimum
QBO East
warm, disturbed
polar vortex
QBO
West
cold, undisturbed
polar vortex
Holton and Tan (1980, 1982)
Solar Maximum
cold, undisturbed
polar vortex
warm, disturbed
polar vortex
Labitzke (1987), Labitzke
and van Loon (1988)
• 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
°C
Solar Minimum
Solar Maximum
E
W
QBO east warmer
Matthes et al. (2004)
QBO west 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)
Model Description UKMO StratosphereMesosphere 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
Polar Temperature at 24 km
Experiment A: Varying
the Bottom Boundary
Experiment B: Varying the
Equatorial Winds
100 m
150 m
+40 ms-1
+20 ms-1
Time
200 m
250 m
0 ms-1
-20 ms-1
Identical
300 m
350 m
-40 ms-1
Courtesy of Lesley Gray (2005)
Changing the
tropospheric
forcing or the
equatorial winds
alters the timing
of the warmings
Stratosphere Mesosphere Model expt
Time-series of polar temperature
20-member ensemble
Easterly anomaly imposed in
subtropics at 40-50km to
mimic a solar minimum
anomaly
Timing of sudden warmings is
very variable in control run
Courtesy of Lesley Gray (2005)
Variance of NP temperature at 24 km in UKMO GCM exp.
SAO + deep QBO
control
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 QBO
Relaxation 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
WACCM Annual Mean Results - Differences
Ozone and Temperature (Max-Min): QBO East experiments
Ozone (%)
Temperature (K)
+0.75K
+3%
+0.2K
+0.5K
99%
+2.5%
+1%
+3%
95% significant
 Maxima in temperature and ozone comparable to observations
 relative minimum in the middle stratosphere
 secondary maximum in the lower stratosphere
Matthes et al. (2006b), to be submitted
Comparison NH Winter Response
WACCM versus FUB-CMAM
Difference
•WACCM: ozone calculated interactively
•FUB-CMAM: ozone prescribed
Zonal Mean Wind Differences - Models vs. Observations
WACCM 4x5 WACCM 1.9x2.5
FUB-CMAM
Observations
NCEP-CPC (1979-1998)
Nov
Dec
Jan
Matthes et al. (2006b)
Matthes et al. (2004)
WACCM NH Winter Signal
- Lower Stratosphere and Troposphere
+1K
Dec T max-min (K)
Jan T max-min (K)
60S 30S
Eq 30N 60N
Jan omega min (hPa/s)
Jan omega max-min (hPa/s)
60S
30S Eq 30N 60N
 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)
Jun omega min (hPa/s)
Jun omega max-min (hPa/s)
+0.5K
60S
30S Eq 30N 60N
60S 30S
Eq 30N 60N
 first model results that confirm observational study about influence on
Hadley and Walker circulation from e.g., van Loon et al. (2004), Kodera(2004)
WACCM - Impact of Different Horizontal
Resolution
T90N @ 10hPa
U60N @ 10hPa
4˚x 5˚
SMIN
Jul
Sep
Nov Jan Mar May
Jul
Sep
Nov Jan Mar May
more SSWs!
1.9˚x 2.5˚
SMIN
Jul
Sep
Nov Jan Mar May
Jul
Sep
Nov Jan Mar May
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 selfconsistent 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)
