18 September 2015 Volume 1 Issue 24

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1 18 September 2015 Volume 1 Issue 24 THE SNOWMAN, THE KID AND SOL Water resources in the western United States are an intersection of climate, precipitation and temperature. In good years, each plays well together and we end up with plentiful rainfall and a large snowpack that stays well into the early summer gradually replenishing our reservoirs and aquifers. Under those conditions, we can happily continue our day-to-day lives without change. In off years, the reduced availability of water begins to hamper our activities. In really off years, we get the conditions that result in extreme dryness exacting its toll: significantly reduced water availability, significantly decreased soil moisture, increased wildfire activity, increased temperature impacts on fish and wildlife, and increased anxiety for everyone. THE SNOWMAN As climate variability increases, we are SNOW WATER EQUIVALENTS (RECONSTRUCTED) 2 increasingly living at the extremes of the norm. A recent analysis by the University of Arizona s Laboratory of Tree- Ring Research finds the most recent snowpack accumulation in California s Sierra Nevada Mountains at 5 percent of the historic average. More importantly, the study places this low value in the context of history: Our study really points to the extreme character of the winter. This is not just unprecedented over 80 years it s unprecedented over 500 years, said Valerie Trouet, an associate professor of dendrochronology at the University of Arizona Laboratory of Tree-Ring Research. 1 The University of Arizona study also reinforces the impact that temperature can have on the short and long-term availability of water in the Southwest: The 2015 record low snowpack coincides with record high California January March temperatures and highlights the modulating role of temperature extremes in Californian drought severity. Snowpack lows, among other drought metrics, are driven by the cooccurrence of precipitation deficits and high temperature extremes, and we find that the exacerbating effect of warm winter temperatures is stronger at low than at high Sierra Nevada elevations. 3

2 THE KID Extrapolating from the implications of the University of Arizona study, the current development of a strong El Niño condition may have a compounding effect on water resources. Strong El Niño conditions usually result in increased precipitation that are good for drought conditions. The impact, however, is quite variable. The National Oceanographic and Atmospheric Administration (NOAA) has observed: EL NIÑO CLIMATE PATTERN Over California and the Southwest, the relationship between El Niño and above-average precipitation is weaker, and it depends significantly on the strength of the El Niño. The stronger the episode (i.e., the larger the sea surface temperature departures across the central equatorial Pacific are), the more reliable the signal in this region has been. 4 The predicted El Niño for indicates that the next two years may be the hottest on record, 5 resulting in a warming pattern providing the beneficial effects of El Niño s precipitation. The downside to this is that as the temperature increases, less of this precipitation will fall and be stored as snow. The result could be that despite being inundated with rain, the parched soil conditions in the Southwest (a result of the region registering a full year s water deficit 6 ), will result in much of that precipitation generating floods and run-off conditions, as opposed to replenishing regional storage. SEA SURFACE TEMPERATURE (SST) ANOMALY (NOAA) 7

3 Reducing the availability of snowpack results in water that cannot be stored for future use. So despite the potential heavy rains from El Niño, we could still exit this climatic condition with a deficit in storage. SOL Another climatic driver is the source of all our energy here on Earth the sun. Through a number of mechanisms, the sun s output drives weather and climate, including our annual seasons. But there are longer term cycles that also impact us. Solar energy output from the sun varies with regular frequency over an eleven year cycle (roughly proportional to the number of sunspots observed 8 ) but fluctuating amplitude. Changes in this output can have dramatic impacts here on Earth, particularly in those areas that are on the edges of climatic stability. Areas like the southwest United States. Paleoclimate analyses have aligned anthropologic events with climate and solar events. One of the most notable is the abandonment of the Four Corners regions of the United States in the late 13th and early 14th centuries (CE). Archaeological, climate and solar data all point to a significant drying of the region, which drove a process of civil upheaval resulting in a mass exodus from the area. At the height of these events, solar output was high 9, resulting in lower Colorado River levels 10, reduced agricultural growing periods and increased conflict. 11 ANTHROPOLOGIC IMPACTS OF DROUGHT The questions then are:»» Can we anticipate how the sun s output may impact our climate over the next few years?»» Will we see a sympathetic alignment of low snowpack, high temperatures and high solar output?

4 The good news is that based on data collected by NASA s Ames Research Center, the sun is exiting a maximal output condition period which should reduce the impacts of solar irradiance. We are still a few years out from the minimum condition, though, and the climate impact lags the solar irradiance by one to two years. As such, we re unlikely to see the full benefit of reduced solar output for another five years. CORRELATION OF NORTH ATLANTIC OSCILLATION WITH SOLAR ACTIVITY 13 ADAPTATION As we know from history, climatic variability can have dramatic impacts on civilization. Whether it is too much water, too little water or too much instability, the failure to adapt can be terminal. With the availability of high frequency, high resolution data, we can make choices that improve our odds of adapting. With respect to water, that means getting smarter in how, why, where and when we use it. FATHOM not only provides for the economical adoption of advanced metering infrastructure, meter data management, customer information and customer presentment, it provides the repository of highly granular consumption data that can form the basis for management practices that increase the longevity of supply. And this data can also form the basis for predictions of the impact of external factors like the Snowman, the Kid and Sol. REFERENCES 1 University of Arizona. Sierra Nevada snowpack lowest in five centuries. ScienceDaily. releases/2015/09/ htm (accessed September 15, 2015). 2 S. Belmecheri, F. Babst, E. Wahl, D. Stahle, V. Trouet, Multi-century evaluation of Sierra Nevada snowpack, Supplementary Information, Nature Climate Change (2015) doi: /nclimate2809 Published online 14 September S. Belmecheri, F. Babst, E. Wahl, D. Stahle, V. Trouet, Multi-century evaluation of Sierra Nevada snowpack, Nature Climate Change (2015) doi: /nclimate2809 Published online 14 September (accessed 15 September 2015) 5 (accessed 15 September 2015) 6 FATHOM Drought Watch, Vol. 1, Issue 18, 7 August 2015 ( Drought-Watch-v1.18.pdf) Charles A. Perry, Kenneth J. Hsu, Geophysical, archaeological, and historical evidence support a solar-output model for climate change, Proc. Natl. Acad. Sci. USA, November 7, 2000 vol. 97 no , ypnas

5 10 D.M. Meko, et al World Data Center for Paleoclimatology, Upper Colorado River Flow Reconstruction. IGBP PAGES/World Data Center for Paleoclimatology, Data Contribution Series # NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. 11 D. Roberts, In Search of the Old Ones: Exploring the Anasazi World of the Southwest, Simon & Schuster (April 9, 1997) 12 R. Thiéblemont, K. Matthes, N. Omrani, K. Kodera, F. Hansen, Solar forcing synchronizes decadal North Atlantic climate variability, Nature Communications 6, doi: /ncomms September GEOMAR Helmholtz Centre for Ocean Research Kiel (