1. Climate Variability and Climate Change in the U.S.-Mexico Border Region Upper San Pedro Partnership Technical Committee Meeting Cochise College – Sierra Vista, Arizona – July 26, 2007 Gregg Garfin Climate Assessment for the Southwest Institute for the Study of Planet Earth University of Arizona

2. Atmospheric Circulation: Winter H Mike Crimmins, University of Arizona

3. Atmospheric Moisture: Winter DRY MOIST Mike Crimmins, University of Arizona

4. Atmospheric Circulation: Winter H Mike Crimmins, University of Arizona

5. Atmospheric Circulation: Summer Bermuda High H Mike Crimmins, University of Arizona

6. Atmospheric Moisture: Summer DRY MOIST Mike Crimmins, University of Arizona

8. Redistribute energy, moisture Persistent changes: Duration 1-3 years Recur every 2-7 years El Niño-Southern Oscillation (ENSO) warm cool warm ~~ Slide courtesy of Greg McCabe, USGS

9. El Niño: Winter Effects U.S. Increased ephemeral channel recharge Source: NOAA Climate Prediction Center http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensocycle/winter25%25.gif

10. La Niña: Winter Effects U.S. Drought circulation pattern Source: NOAA Climate Prediction Center http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensocycle/winter25%25.gif

11. Climate Division 7 Southeastern Arizona 1895-2002

12. Pacific Decadal Variability Discovered in 1990s Occurs every 20-30 years Mechanism likely –ENSO –Kuroshio Current –Aleutian Low Courtesy of N. Mantua – University of Washington Mantua et al., 1997 Bulletin of the American Meteorological Society

13. 91 84 82 87 7978 Negative PDO 113 117 131 115 123119 120 Positive PDO AZ PDO (Oct.-Sept.) Precipitation % Average Based on Maxwell and Holbrook, NWS Tucson

14. http://www.ncdc.noaa.gov/oa/climate/research/teleconnect/teleconnect.html

15. Shift to Low Index?

16. Positive AMO Phase Atlantic Multidecadal Oscillation - AMO Slide courtesy of Greg McCabe, USGS West: Warm, dry, high pressure Associated with 1950s and late-1500s droughts

17. Pacific negative + Atlantic positive. McCabe et al., 2004 Proceedings of the National Academy of Sciences. Drought Frequency % (25 = expected) high drought frequency low drought frequency

18. OBSERVED CHANGES

19. Global Energy Balance From http://www.bom.gov.au

20. http://www.grida.no/climate/vitalafrica/english/09.htm

21. 380 Most rapid change in the last 10,000 years 280 CO 2 Changes http://www.grida.no/climate/vital/02.htm

22. http://lwf.ncdc.noaa.gov/oa/climate/research/anomalies/anomalies.html

23. Western Regional Climate Center June-May Temperature Cochise County

24. Western Regional Climate Center June-May Precipitation Cochise County

25. Courtesy of Noah Knowles, USGS Trends in Nov-Mar Snowfall Fraction More Rain, Less Snow More Snow, Less Rain

26. Dramatic Warming Episodes Losses of 30-60%

27. Stewart et al. 2005 Journal of Climate

30. PROJECTIONS

31. GCM Models, based on physics –Atmosphere, ocean Some processes must be estimated, scaled to large regions Processes tuned and validated using historical data Models driven by forcing factors –Solar, volcanic, GHGs, aerosols (particles)

32. Scenario descriptions Global integrationRegionalism Economic emphasis A1B Balanced energy A2 fragmented A1FI Fossil-fuel Intensive A1T high-Tech renewables Environmental emphasis B1B2 local IPCC 3 rd Assessment Report

33. Data: IPCC 4 th Assessment

34. IPCC 4 th Assessment: Working Group I, Chapter 11, Regional Projections Annual Temperature: End of 21 st Century

35. Annual Precipitation: End of 21 st Century IPCC 4 th Assessment: Working Group I, Chapter 11, Regional Projections

36. Atmospheric Circulation: Winter H

37. H

38. A1B

42. Heat Waves Diffenbaugh et al., 2005 Proceedings of the National Academy of Science Increased Length of Average Heat Wave (days) 4 models and A2 “Business as Usual” emissions scenarios in a Regional Climate Model 2071-2095 Minus 1961-1985

43. Diffenbaugh et al., 2005 Proceedings of the National Academy of Science Annual Evapotranspiration A2

44. Diffenbaugh et al., 2005 Proceedings of the National Academy of Science Increased Fraction of Extreme Precipitation A2

45. What does global warming have in store for El Niño? Latest word: Study comparing 20 different climate models No clear consensus! Models still do not simulate El Niño well… “Best” models showed smallest changes More La Niña-like More El Niño-like Collins, 2005, Climate Dynamics

46. Climate Change Water Challenges in the Arizona-Sonora Border Region Increased temperatures: very likely Decreased precipitation: likely Potential direct impacts and concerns: Decreased surface water supply reliability Increased evaporation Reduced minimum flows for fish Earlier peak flow timing Greater likelihood of extreme events: drought, flood

47. Incorporating Climate Into Streamflow Prediction Statistical models (PPT, SWE, Streamflow) Historical data are assumed to be a sample of future events Ensemble streamflow prediction (ESP) Conceptual hydrologic models Soil moisture accounting, Snow model Current basin initial states Multiple meteorological inputs TEM, PPT, Estimated Upstream flow Probabilistic distribution of future events, daily data aggregated to seasonal water volume

48. Franz et al., Journal of Hydrometeorology, 2005

49. Incorporating Climate Into Streamflow Prediction Force models with data adjusted for seasonal outlook terciles, or ENSO, PDO, AMO phases Assumptions Historical data are representative of future states Accurate understanding of processes and their sensitivities to climate variations

50. Dennis Lettenmaier, University of Washington

51. Gregg Garfin Climate Assessment for the Southwest Institute for the Study of Planet Earth gmgarfin@email.arizona.edu 520-622-9016 www.ispe.arizona.edu/climas http://www.climate.noaa.gov/cpo_pa/risa/