1. The Whole Atmosphere Community Climate Model: Overview, Current Research and Future Plans Rolando Garcia

2. CCSM June 20062 Outline 1.WACCM overview 2.Research with WACCM –Solar cycle impacts –1950-2003 trend simulations –21 st century prognostic simulations –Upper atmosphere dynamics (2-day wave) 3. Future work

3. CCSM June 20063 Acknowledgments… Doug Kinnison (ACD) Dan Marsh (ACD) Katja Matthes (Free University Berlin) Astrid Maute (HAO) Jadwiga Richter (CGD) Fabrizio Sassi (CGD) Stan Solomon (HAO) the following colleagues contributed to the work presented in this talk...

4. CCSM June 20064 and, of course, Byron Boville … … to whose memory this talk is dedicated

5. CCSM June 20065 1. Overview of WACCM

6. CCSM June 20066 NCAR Whole Atmosphere Community Climate Model MOZART-3 CAM3 WACCM-3 TIME-GCM Chemistry Dynamics + Physical processes MLT Processes + extensions Based on The Community Atmosphere Model (CAM3) 0-140 km (66 levels;  z =1.3 km in lower stratosphere to 3 km in thermosphere) Finite-volume dynamics 30 minute time step MOZART-3 chemistry package (55 species) Upper atmosphere extensions: –Lindzen GW parameterization –Molecular diffusion –NO cooling –non-LTE long-wave heating in the 15 µm band of CO 2 and the 9.6 µm band of O 3

7. CCSM June 20067 WACCM3 additions The following processes are now dealt with in a self- consistent manner in WACCM: –Solar variability –Chemical heating –Airglow –Ion chemistry (5 ion species & electrons) –EUV and X-ray ionization –Auroral processes Particle precipitation Ion drag Joule heating Chemistry is completely interactive with dynamics

8. CCSM June 20068 Current interdivisional collaborators Current external collaborations Mark Baldwin (NWRA) – annular modes Natalia Calvo (U. of Madrid) and Marco Giorgetta (MPI, Hamburg) – effects of ENSO on the middle atmosphere; comparison of models and reanalysis data Charlie Jackman (NASA/Goddard) – impacts of solar proton events on ozone Judith Perlwitz and Martin Hoerling (NOAA/Boulder) – climate impacts of changing chemistry and SST Cora Randall et al. (CU/LASP) [plus John Gille (ACD/HIRDLS) and Laura Pan (ACD/UTLS initiative)] – process-oriented evaluation of chemistry-climate models vs. observations

9. CCSM June 20069 Zonal-Mean T: JULY WACCM 140 K 270 K 200 K SABER: broadband IR radiometer onboard TIMED satellite; measures T, O3, H 2 O, CO 2

10. CCSM June 200610 Zonal-Mean U: JULY WACCM URAP/UKMO: UARS/UK Met Office reference atmosphere, based upon UARS satellite observations assimilated with the UK Met Office GCM

11. CCSM June 200611 Zonal-Mean O 3 : JULY 11 ppm WACCM SABER SABER: broadband IR radiometer onboard TIMED satellite; measures T, O3, H 2 O, CO 2

12. CCSM June 200612 2. Research with WACCM

13. CCSM June 200613 Solar min/max simulations Fixed solar minimum and solar maximum conditions (constant F10.7 and Kp typical of minimum/maximum)

14. CCSM June 200614 definition of solar variability 15 years ea. solar maximum and minimum conditions S max : F10.7 = 210, Kp = 4 S min : F10.7 = 77, Kp = 2.7 Photolysis and heating rates are parameterized in terms of f10.7 and Kp

15. CCSM June 200615 SSU/MSU4 (1979-2003) Courtesy of Bill Randel (2005) WACCM (annual mean) Stratospheric temperature response

16. CCSM June 200616 SAGE I/II ozone change 2.4% 3.6% % ozone change for 1% change in Mg II (~6% Mg II change over solar cycle) WACCM (annual mean) % ozone change over solar cycle

17. CCSM June 200617 Ozone column vs. f10.7 regressions: WACCM and observations WACCM 1950-2003WACCM 1979-2003

18. CCSM June 200618 An ensemble of “retrospective” runs, 1950-2003, including solar variability, observed SST, observed trends in GHG and halogen species, and observed aerosol surface area densities (for heterogeneous chemistry) 1950-2003 trends simulation

19. CCSM June 200619 Calculated and Observed Ozone Trends SAGE-I 1979-1981 and SAGE-II 1984-2000 Red inset on left covers approximately same region as observations on right Agreement is quite good, including region of apparent “self-healing” in lower tropical stratosphere

20. CCSM June 200620 Total Column Ozone Trends (Global)

21. CCSM June 200621 Calculated and Observed Temperature Trends SSU + MSU 1979-1998 Red inset on left covers approximately same region as observations on right Note comparable modeled vs. observed trend in upper stratosphere, although model trend is somewhat smaller

22. CCSM June 200622 Temperature Trends (Global), K / Decade Courtesy of Bill Randel (NCAR )

23. CCSM June 200623 Whole-atmosphere zonal-mean T trend 1950-2003 Note lack of trend at 80-90 km Ozone decrease and CO 2 increase CO 2 increase (greenhouse effect) Antarctic O 3 hole CO 2 decrease

24. CCSM June 200624 An ensemble of prognostic runs, 1975-2050, to look at climate change and ozone recovery in the 21 st century. Follows WMO A1B scenario. An additional ensemble assumed constant CO 2, CH 4, N 2 O to assess the role of stratospheric cooling by these gases. 21 st century prognostic simulations

25. CCSM June 200625 Global-mean ozone column 1950-2003 sim 1980-2050 sim (A1B scenario) column minimum ~2000-2010 recovery to 1980 values ~2040 smoothed with 12-month running mean 21st century prognostic simulation (red) shown together with the results of the 1950–2003 simulation (black) discussed earlier

26. CCSM June 200626 Global-mean ozone column all smoothed with 12-month running mean A1B scenario “no-climate change” scenario A1B scenario produces “super-recovery” compared to “no climate change” simulation wherein CO 2, N 2 O, CH 4 are held at 1995 values. This is due to colder stratospheric T in A1B scenario.

27. CCSM June 200627 Stratospheric “age of air” is also affected by changing GHG 1950-2003 1980-2050 A1B 1980-2050 fix GHG

28. CCSM June 200628 Apart from the tides, the 2-day wave dominates high-frequency variability in the MLT Has large amplitude at solstice, especially in the summer hemisphere Has been interpreted as a normal mode (e.g., Salby, 1981), a result of baroclinic instability (e.g., Plumb, 1983), and a combination of both (e.g., Randel, 1994) Comparison of WACCM simulations and observations by the SABER instrument on the TIMED satellite Upper atmosphere dynamics: The 2-day wave

29. CCSM June 200629 SABER T Spectrum Similar spectral behavior in WACCM calculations as in SABER data Wavenumber/frequency T spectra at 36°N and 80 km (July) Note concentration of variance along line of constant c in both data and model WACCM T Spectrum

30. CCSM June 200630 Components of 2-day wave in SABER data and WACCM simulation k=3, ~2-day SABER k=4, ~1.8 day SABER SABER observations and WACCM results for July WACMM

31. CCSM June 200631 … more components of 2-day wave in SABER data and WACCM k=2, ~3 day SABER k=2, ~ 2 day SABER WACCM

32. CCSM June 200632 3. Future Work Climate sensitivity to doubling CO 2 : CAM vs. WACCM Impact of ozone hole and changing tropical SST on Arctic/Antarctic surface climate Climatology of stratospheric sudden warmings: impacts of resolution, gravity wave parameterization, SST variability; relationship to annular modes Process-oriented evaluation of model chemistry (comparisons with EOS/Aura observations) Impact of solar proton events on mesospheric and stratospheric composition Energy budget and dynamics of the MLT – comparison with SABER observations

33. CCSM June 200633 To keep in touch …. WACCM website and new model release WACCM website is being hosted under ACD (http://waccm.acd.ucar.edu/index.shtml) Website has been updated and reformatted 2006 CSL proposal posted on site WACCM3 description to be completed Release WACCM3 in summer 2006