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 2 National Center for Atmospheric Research, Boulder, Colorado, USA Marie Curie Outgoing International Fellowship

Courtesy of Kuni Kodera (2005) Possible Ways for Solar Influence on Climate Sun Sun Visible UV Ozone T, U Strat. Strat. trop. trop. Dynamical impact Radiative impact ? Earth Earth Direct Influence Indirect Influence Courtesy of Kuni Kodera (2005)

Mechanism – Influence of the 11-Year Solar Cycle Thermosphere UV radiation Mesosphere Direct influence on temperature Influence on ozone Change of meridional temperature gradient Stratopause QBO SAO Gray et al. (2001a,b) Gray et al. (2003, 2004) Labitzke (1987), Labitzke and van Loon (1988) Circulation changes (wind, waves, meridional BD circulation) Kodera and Kuroda (2002) Stratosphere Modeling Matthes et al. (2004) ? Change of Hadley cell 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) NH polar response Kodera (2002, 2003), Ogi et al. (2004), Kuroda and Kodera (2004, 2006) SH Matthes et al. (2006a) Tropopause Überleitung zur nächsten Folie: hervorheben des Einflusses äquatorialer Winde auf NH Winterentwicklung. Indirect influence, difficult to measure Troposphere Ocean ?

Some Observational Facts

Positive Correlations Sun - Stratospheric Parameters Reference checken Labitzke (1999)

Observed Solar Signal in Temperature Annual Mean NCEP/CPC (1980-1997) 48 km 16 km 60N 60S SSU/MSU4 (1979-1997) +2.5 K 60N 60S Hood (2004) Scaife et al. (2002) +0.8 K -1 K +1 K +0.25 K SSU/MSU4 (1979-2003) + 0.9 K Courtesy of W. Randel (2005) ERA40 (1979-2001) 60S 60N 48 km 16 km + 1.75K + 0.5K Crooks & Gray (2005) Umstrittenes beobachtetes Temperatursonnensignal! Schwierigkeit der Vergleichbarkeit mit Modell, da nur kleiner Teil komplett abgedeckt wird (Adams Bild!!)

Observed Solar Signal in Ozone Annual Mean Lee and Smith (2003) SBUV (1979-1989) SAGE (1984-1998) 16km 50km 21km 60N 60S Models vs. Observations - Tropics Calisesi and Matthes (2006) updated from Shindell et al. (1999)

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) 1000 Eq ‒ f v*∼ ∇•F ? Kodera and Kuroda (2002)

Development of Modeling Solar Influence on MA 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 changes without 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 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)

Perpetual Solar Maximum Experimental Design Perpetual Solar Maximum Perpetual Solar Minimum 15 years Ozone changes (%) Annual Mean Irradiance changes max-min (%) +3 % +2.5 % Data from Haigh (1994) 5-8 % Hervorheben, dass Modelle keine interne QBO haben Dazu wird Schwerewellenparametrisierung, ausreichende räumliche Auflösung, sowie eine realistische Simulation tropischer Konvektion benötigt (z. B. Giorgetta et al., 2002; Scaife et al., 2000a) Data from Shindell et al. (1999) Data from Lean et al. (1997)

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 = pre-requisite 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: Hochaufgeloestes Strahlungsschema (43 Baender))

FUB-CMAM vs. Observations (Max-Min) – NH Winter NCEP/CPC (1979-1998) ERA40 (1979-2001) Matthes et al. (2004) FUB-CMAM 80 km stratospheric response tropospheric Nov „poleward-downward“ movement modulation of the PNJ at high lats Dec comparable with observations (e.g., Kodera, 1995) Jan Feb 0.1 0.4 hPa 850 1000 update of Kodera (1995) Gray et al. (2004)

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 Warming in tropical lower stratosphere dynamically induced! Überleitung zur nächsten Folie Matthes et al. (2006a)

Impact on Tropospheric Circulation Pattern Ev. Nur diese Abb. Zeigen, um Zeit zu sparen! Koennte aber auch kritisch sein, da in WACCM nicht so ganz klar ist, woher Erwaermung der unteren Stratosphaere kommt…. VORSICHT! Kodera, in preparation (2006)  Jo Haigh will talk about stratosphere-troposphere coupling

Observations: QBO-Solar Signal QBO East warm, disturbed polar vortex QBO West cold, undisturbed Solar Minimum Solar Maximum warm, disturbed polar vortex cold, undisturbed Labitzke (1987), Labitzke and van Loon (1988) Holton and Tan (1980, 1982) 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) Salby und Callaghan eventuell erst spaeter am Ende erwaehnen, da hier sonst verwirrend, da das mit den jetzigen Modellstudien, die ich vorstelle nicht gezeigt werden kann…. Hmm, Palmer and Gray (2005) ev. Doch!!!!

QBO-Sun Interaction in the FUB-CMAM 10hPa north pole temperature +/-2σ Solar Minimum QBO west warmer Solar Maximum °C E W Sowohl LvL welche sich nur auf Winde in der unteren Stratosphaere beziehen als auch Gray, da Wind im Modell ueber die gesamte Stratosphaere erst dieses Ergebnis brachte!!! 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) 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 100 m 150 m +40 ms-1 +20 ms-1 Polar Temperature Time 200 m 250 m 0 ms-1 -20 ms-1 Identical 300 m 350 m -40 ms-1 Changing the tropospheric forcing or the equatorial winds alters the timing of the warmings Courtesy of Lesley Gray (2005)

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 FUB-CMAM: Hochaufgeloestes Strahlungsschema (43 Baender))

WACCM Annual Mean Results - Differences Ozone and Temperature (Max-Min): QBO East experiments Temperature (K)  Maxima in temperature and ozone comparable to observations +0.75K +3% +2.5%  relative minimum in the middle stratosphere +0.2K +1%  secondary maximum in the lower stratosphere +0.5K +3% 99% 95% significant 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 NCEP-CPC (1979-1998) WACCM 4x5 Matthes et al. (2006b) WACCM 1.9x2.5 FUB-CMAM Nov Dec Jan Matthes et al. (2004)

WACCM NH Winter Signal - Lower Stratosphere and Troposphere Dec T max-min (K) Jan omega min (hPa/s) Jan omega max-min (hPa/s) Eq 30N 60N 30S 60S +1K Jan T max-min (K) 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 omega min (hPa/s) Jun omega max-min (hPa/s) Eq 30N 60N 30S 60S Jun T max-min (K) +0.5K 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 Jul Sep Nov Jan Mar May more SSWs! 4˚x 5˚ SMIN 1.9˚x 2.5˚ SMIN 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 self- consistent QBO Test locking of QBO with annual cycle in mechanistic model

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)