1. Recent variability of the solar spectral irradiance and its impact on climate modelling - TOSCA WG1 Workshop, May 2012, Berlin Stratospheric and tropospheric effects of solar activity K. Tourpali Lab. Of Atmospheric Physics Aristotle University of Thessaloniki, Greece CCMVal-2 PIs

2. Questions  How does the Sun influence natural climate variability?  What is the role of the stratosphere - how does the exchange with the troposphere work?  Which mechanisms (top-down, bottom-up) are important for solar influences on climate?  Can climate models represent the observed signals? Recent variability of the solar spectral irradiance and its impact on climate modelling - TOSCA WG1 Workshop, May 2012, Berlin

3. Observations: Solar cycle variations in  Stratosphere: Temperatures and geopotential heights (Labitzke and van Loon)  Sea surface: temperatures, mean sea level pressures  Winds: Zonal, Vertical  Tropical circulations : Hadley, Walker circulation  Mid / high latitude ‘annular modes’  Clouds / precipitation Recent variability of the solar spectral irradiance and its impact on climate modelling - TOSCA WG1 Workshop, May 2012, Berlin

4. Observations: Solar cycle variations in  Stratosphere: Temperatures and geopotential heights (Labitzke and van Loon)  Sea surface: temperatures, mean sea level pressures  Winds: Zonal, Vertical  Tropical circulations : Hadley, Walker circulation  Mid / high latitude ‘annular modes’, especially Arctic Oscilaltion  Clouds / precipitation Recent variability of the solar spectral irradiance and its impact on climate modelling - TOSCA WG1 Workshop, May 2012, Berlin

5. SPARC CCMval Activity Solar signal in CCMVal-2 runs Recent variability of the solar spectral irradiance and its impact on climate modelling - TOSCA WG1 Workshop, May 2012, Berlin Simulation Ref-B1: Reproducing the past transient run from 1960 - to the present All forcings taken from observations

6. Recent variability of the solar spectral irradiance and its impact on climate modelling - TOSCA WG1 Workshop, May 2012, Berlin

7. SPARC Report -Solar signal in CCMVal-2 runs 25N-25S The signal in upper stratosphere is reasonably represented in models However, there are large differences between CCMs But also between observation data sets! possible aliasing of signal – ENSO, volcanoes Recent variability of the solar spectral irradiance and its impact on climate modelling - TOSCA WG1 Workshop, May 2012, Berlin

8. SPARC Report - Solar signal in CCMVal-2 runs Recent variability of the solar spectral irradiance and its impact on climate modelling - TOSCA WG1 Workshop, May 2012, Berlin

9. Climate Chemistry Models Ref-B1 of CCMVal-2  AMTRAC3  CAM3.5  CCSRNIES  CMAM  CNRM-ACM  E39CA ?? Gpz not available  EMAC  LMDZrepro  MRI  NiwaSOCOL  SOCOL  UMSLIMCAT  WACCM To compare:Era-40 reanalysis No solar cycle! GEOSCCM ULAQ UMUKCA-METO UMUKCA-UCAM UMETRAC

10. Recent variability of the solar spectral irradiance and its impact on climate modelling - TOSCA WG1 Workshop, May 2012, Berlin Data and method of analysis  Inputs from CCMs (monthly averages) : Geopotential heights (3D) Zonal winds and temperature profiles (zonal means) Ozone total column and profile  Analysis: Regression analysis on zonal wind focus on northern hemisphere winter Annular mode in the Northern hemisphere winter (DJF) geopotential heights : 850hPa, 500hPa, 10hPa

11. Linear regression Regression analysis on zonal wind focus on northern hemisphere winter Recent variability of the solar spectral irradiance and its impact on climate modelling - TOSCA WG1 Workshop, May 2012, Berlin The autoregressive linear model in general form: Courtesy of Markus Kunze

12. Annular mode analysis EOF analysis was performed on: - detrended series of geopotential heights - separated in solar maximum and minimum years the 1 st EOF pattern represents the Arctic Oscillation variability AO-index is the normalised leading PC Winter mean fields regressed onto this AO-index Correlation between the AO-index and zonal mean wind and zonal mean temp I have not touched ozone yet! Recent variability of the solar spectral irradiance and its impact on climate modelling - TOSCA WG1 Workshop, May 2012, Berlin

13. zonal wind response AMTRAC3 CMAM SOCOL WACCM Nov Dec Jan Feb Mar

14. Solar signal in AO mode winter 850 hPa geopotential height Era-40 AMTRACCMAM meters

15. Solar signal in AO mode winter 850 hPa geopotential height Era-40 SOCOLWACCM meters

16. Solar signal in AO mode winter 500 hPa geopotential height Era-40 AMTRACCMAM meters

17. Solar signal in AO mode winter 500 hPa geopotential height Era-40 SOCOLWACCM meters

18. Solar signal in winter AO mode winter 10 hPa geopotential height Recent variability of the solar spectral irradiance and its impact on climate modelling - TOSCA WG1 Workshop, May 2012, Berlin Era-40 Amtrac waccm meters

19. Recent variability of the solar spectral irradiance and its impact on climate modelling - TOSCA WG1 Workshop, May 2012, Berlin Arctic Oscillation  Reanalysis: clear difference between solar max and min years.  A number of models with solar cycle variability reproduce this

20.  What does a model with no SC show? Recent variability of the solar spectral irradiance and its impact on climate modelling - TOSCA WG1 Workshop, May 2012, Berlin 850 hPa

21. Recent variability of the solar spectral irradiance and its impact on climate modelling - TOSCA WG1 Workshop, May 2012, Berlin

22. Extension of the signal in the stratosphere Era-40 Correlation to zonal wind 850 mb AO index

23. Extension of the signal in the stratosphere amtrac3 Correlation to zonal wind Recent variability of the solar spectral irradiance and its impact on climate modelling - TOSCA WG1 Workshop, May 2012, Berlin

24. Summary (Conclusions – not there yet!)  Chemistry-Climate Models do represent the solar max vs min changes in the shape of AO  How about the vertical extension of the signal?  Do volcanic eruptions (or ENSO) disrupt the signal?

25. Recent variability of the solar spectral irradiance and its impact on climate modelling - TOSCA WG1 Workshop, May 2012, Berlin And, more Questions!  What are the differences in ozone and temperature if a new SSI forcing is used?  Will the stratospheric-tropospheric signals show up if another SSI forcing is used? Stronger or weaker?  Will we find a better comparison to observations?  Will our current perception of mechanisms (top-down, bottom- up) change?

26. Recent variability of the solar spectral irradiance and its impact on climate modelling - TOSCA WG1 Workshop, May 2012, Berlin Thank you!