New Horizons in Paleoclimatology Toby Ault 5.6.2008

1. New Horizons in Paleoclimatology Toby Ault 5.6.2008

2. Overview:  Proxy-model integration  Experiment design  Results  Future work

3. Overview:  Proxy-model integration  Experiment design  Results  Future work

4. Overview:  Proxy-model integration  Experiment design  Results  Future work

5. Overview:  Proxy-model integration  Experiment design  Results  Future work

6. Overview:  Proxy-model integration  Experiment design  Results  Future work

7.  Proxy-Model Integration

8. GCM Data: Proxy Data: 10’s of km 100’s of km Image from: http://ipcc-wg1.ucar.edu/wg1/Report/AR4WG1_Print_Ch11.pdf

9. 1°x1° (~111 km)

10. Case example: the Monsoon

11. August, 2006 PRISM mean precip. (mm/day) http://www.prism.oregonstate.edu/products/viewer.phtml?file=/pub/prism/us/graphics/ppt/2000-2009/us_ppt_2006.08.png&year=2006&vartype=ppt&month=08&status=final&zoom=yes

12. Observational Monsoon 0.5˚x 0.5˚ JJA mean precip. (mm/day) *Mitchell, T. D., and P. D. Jones (2005), An improved method of constructing a database of monthly climate observations and associated high-resolution grids, International Journal of Climatology, 25(6), 693-712.

13. CCSM3’s Monsoon JAS mean precip. (mm/day)

14. CCSM3’s Monsoon What about the future? JAS mean precip. (mm/day)

15. CCSM - No change GFDL - Weaker UKMO - Stronger *Joellen Russell, Pers. comm.

16. CCSM - No change No good consensus… Absent in other models… Turn to proxies! GFDL - Weaker UKMO - Stronger *Joellen Russell, Pers. comm.

17. Mid-Holocene climate http://geochange.er.usgs.gov/sw/impacts/biology/pastclim/

18. Proxies in N. America

19. http://www.swaebr.org/images/Packrat.jpg

20. Wetter summers… OR …drier winters!

21. Playa Lakes: Occasionally filled during Mid-Holocene Likely monsoon related… http://en.wikipedia.org/wiki/Playa

23. Speleothems: Stronger Monsoon Connection to North Atlantic ITCZ shifted northward?

24. Modeling 6ka climates

25. PMIP (Paleoclimate Model Intercomparison Project) Mean JJA precipitation for CCSM 6ka simulation http://www.ncdc.noaa.gov/paleo/modelvis.html

26. Harrison et al., 2003 CCSM3-JJA: 6ka-0ka (mm/day)

27. Harrison et al., 2003 No Change? CCSM3-JJA: 6ka-0ka (mm/day)

28. GCM Data: Proxy Data: 10’s of km 100’s of km Image from: http://ipcc-wg1.ucar.edu/wg1/Report/AR4WG1_Print_Ch11.pdf

29. GCM Data: Proxy Data: Can regional downscaling bridge this gap? 10’s of km 100’s of km

30.  Experiment Design

31. Model: WRF Nesting: None Physics: Defaults X-domain: 119˚W to 110˚W Y-domain: 20˚N to 34˚N Resolution: ~30km Time: Aug. 2-25, 2006 T: 3hrs

32. Boundary Conditions: NCEP/NCAR Reanalysis 2.5˚x 2.5˚ resolution

33.  Results

34. Means NNRP WRF Precipitation (mm/day)

35. Variance NNRP WRF Precipitation variance (mm/day)2

36. August 2006 - NNRP Link to animation

37. August 2006 - WRF Link to animation

38. Smaller scale Better representationof mechanisms

39.  Future Work

40. 1. Comparison with observations 2. Better analysis of dynamics 3. Cumulus parameterization scheme 4. Downscaling modern CCSM3 runs 5. Paleoclimate downscaling

41. 1. Comparison with observations 2. Better analysis of dynamics 3. Cumulus parameterization scheme 4. Downscaling modern CCSM3 runs 5. Paleoclimate downscaling

42. 1. Comparison with observations 2. Better analysis of dynamics 3. Cumulus parameterization scheme 4. Downscaling modern CCSM3 runs 5. Paleoclimate downscaling

43. 1. Comparison with observations 2. Better analysis of dynamics 3. Cumulus parameterization scheme 4. Downscaling modern CCSM3 runs 5. Paleoclimate downscaling

44. 1. Comparison with observations 2. Better analysis of dynamics 3. Cumulus parameterization scheme 4. Downscaling modern CCSM3 runs 5. Paleoclimate downscaling

45. 1. Comparison with observations 2. Better analysis of dynamics 3. Cumulus parameterization scheme 4. Downscaling modern CCSM3 runs 5. Paleoclimate downscaling

46. Acknowledgements: Jason Criscio, Andy Penny, and CCIT - THANKS!