The West’s declining snowpack: is global warming to blame? Philip Mote Climate Impacts Group University of Washington.

Slides:

Advertisements

Similar presentations

– Winter Ecology. Introduction  Global Climate Change  How microbs may be affected by snowpack depth  Temperature/precipitation trends.

Advertisements

1 Climate change and the cryosphere. 2 Outline Background, climatology & variability Role of snow in the global climate system Contemporary observations.

Human-induced changes in the hydrological cycle of the western United States Tim Barnett 1, David Pierce 1, Hugo Hildalgo 1, Tapash Das 1, Celine Bonfils.

The Role Of The Pacific North American Pattern On The Pace Of Future Winter Warming Across Western North America.

Long-term trends in snowpack in the Pacific Northwest Philip Mote, Alan Hamlet, and Dennis Lettenmaier.

Hydrologic Outlook for the Pacific Northwest Andy Wood and Dennis P. Lettenmaier Department of Civil and Environmental Engineering for Washington Water.

Climate recap and outlook Philip Mote, PhD University of Washington Center for Science in the Earth System - Climate Impacts Group Boise, ID October 17,

Climate Change in Idaho Philip Mote Climate Impacts Group University of Washington With contributions from Alan Hamlet, Nate van Rheenan, Richard Slaughter,

What we know about global climate change Philip Mote (206) University of Washington.

Alan F. Hamlet, Phil Mote, Martyn Clark, Dennis P. Lettenmaier Center for Science in the Earth System Climate Impacts Group and Department of Civil and.

Alan F. Hamlet JISAO/CSES Climate Impacts Group Dept. of Civil and Environmental Engineering University of Washington Hydrologic Implications of Climate.

Seasonal outlooks for hydrology and water resources in the Pacific Northwest Andy Wood Alan Hamlet Dennis P. Lettenmaier Department of Civil and Environmental.

Alan F. Hamlet Philip W. Mote Dennis P. Lettenmaier JISAO Center for Science in the Earth System Climate Impacts Group and Department of Civil and Environmental.

Dennis P. Lettenmaier Alan F. Hamlet JISAO Climate Impacts Group and the Department of Civil and Environmental Engineering University of Washington July,

Human-induced changes in the hydrological cycle of the western United States Tim Barnett 1, David Pierce 1, Hugo Hildalgo 1, Tapash Das 1, Celine Bonfils.

Declines in mountain snowpack Philip Mote, Alan Hamlet, Dennis Lettenmaier University of Washington With thanks to NRCS and Iris Stewart ftp://ftp.atmos.washington.edu/philip/SNOWPAPER/

Alan F. Hamlet Dennis P. Lettenmaier Center for Science in the Earth System Climate Impacts Group and Department of Civil and Environmental Engineering.

Alan F. Hamlet Andy Wood Dennis P. Lettenmaier JISAO Center for Science in the Earth System Climate Impacts Group and Department of Civil and Environmental.

What we know about global climate change Philip Mote (206) University of Washington.

Implications of 21st century climate change for the hydrology of Washington October 6, 2009 CIG Fall Forecast Meeting Climate science in the public interest.

Alan F. Hamlet Marketa McGuire Elsner Ingrid Tohver Kristian Mickelson JISAO/CSES Climate Impacts Group Dept. of Civil and Environmental Engineering University.

Global and Regional Climate Change during the 20 th and 21 st centuries January 13, 2011 ENVIR/SMA/ATMS/ESS585 Amy Snover, ATMS

High and Dry: Declining Precipitation in the Mountains of the Pacific Northwest Charles Luce US Forest Service Research. Boise, ID John Abatzoglou University.

Alan F. Hamlet Andy Wood Dennis P. Lettenmaier JISAO Climate Impacts Group and the Department of Civil Engineering University of Washington September,

Hydrologic trends in the West Philip Mote Climate Impacts Group University of Washington Alan Hamlet, Martyn Clark, Dennis Lettenmaier With thanks to Dave.

Alan F. Hamlet Philip W. Mote Martyn Clark Dennis P. Lettenmaier JISAO/SMA Climate Impacts Group and Department of Civil and Environmental Engineering.

Michael Dettinger US Geological Scripps Institution of Oceanography, La Jolla, CA Dan Cayan, USGS/SIO Iris Stewart, SIO Noah Knowles, USGS Recent.

Alan F. Hamlet, Philip W. Mote, Nate Mantua, Dennis P. Lettenmaier JISAO/CSES Climate Impacts Group Dept. of Civil and Environmental Engineering University.

Global climate change and Oregon’s water resources Philip Mote Climate Impacts Group University of Washington Alan Hamlet (UW), Iris Stewart (UCSD) With.

Climate Change in the Pacific Northwest: Impacts and Planning Philip Mote UW Climate Impacts Group University of Washington Climate Science in the Public.

Alan F. Hamlet Philip W. Mote Martyn Clark Dennis P. Lettenmaier Center for Science in the Earth System Climate Impacts Group and Department of Civil and.

Alan F. Hamlet, Philip W. Mote, Nate Mantua, Dennis P. Lettenmaier JISAO/CSES Climate Impacts Group Dept. of Civil and Environmental Engineering University.

Introduction 1. Climate – Variations in temperature and precipitation are now predictable with a reasonable accuracy with lead times of up to a year (

Alan F. Hamlet, Philip W. Mote, Dennis P. Lettenmaier JISAO/CSES Climate Impacts Group Dept. of Civil and Environmental Engineering University of Washington.

Alan F. Hamlet, Philip W. Mote, Dennis P. Lettenmaier JISAO/CSES Climate Impacts Group Dept. of Civil and Environmental Engineering University of Washington.

Figure 1. Map of study area. Heavy solid polygon defines “Cascade Mountains” for the purposes of this study. The thin solid line divides the Cascade Mountains.

Long-term climate and water cycle variability and change Dennis P. Lettenmaier Department of Civil and Environmental Engineering University of Washington.

Opportunities for UCLA/JPL water-related collaborations: Western U.S. focus Dennis P. Lettenmaier Department of Geography University of California, Los.

Global Warming and Its impacts on the Pacific Northwest Dr. Nathan Mantua University of Washington Climate Impacts Group Dr. Nathan Mantua University.

Impacts of Climate Change on Water Resources in Idaho Prepared by Zion Klos PhD Student, College of Natural Resources …feel.

Assessing the Influence of Decadal Climate Variability and Climate Change on Snowpacks in the Pacific Northwest JISAO/SMA Climate Impacts Group and the.

Climate Change and Water Supply: Potential Hydrologic Consequences Guido Franco Technical Lead for Climate Change Research Public Interest Energy Research.

Hydrologic Forecasting Alan F. Hamlet Dennis P. Lettenmaier JISAO/CSES Climate Impacts Group Dept. of Civil and Environmental Engineering University of.

Is the Sierra Nevada going to lose its snow? Investigate how 21 st Century scenarios of climate change impact spring snowpack in California Dan Cayan(1,2),

Climate Change and Water Supplies in the West Michael Dettinger, USGS.

Long-term Trends in Water Supply Forecast Skill

UBC/UW 2011 Hydrology and Water Resources Symposium Friday, September 30, 2011 DIAGNOSIS OF CHANGING COOL SEASON PRECIPITATION STATISTICS IN THE WESTERN.

Alan F. Hamlet, Philip W. Mote, Dennis P. Lettenmaier JISAO/CSES Climate Impacts Group Dept. of Civil and Environmental Engineering University of Washington.

Use of Climate Forecasts in Hydrologic Prediction Applications Alan F. Hamlet Dennis P. Lettenmaier JISAO/CSES Climate Impacts Group Dept. of Civil and.

Alan F. Hamlet, Philip W. Mote, Dennis P. Lettenmaier JISAO/CSES Climate Impacts Group Dept. of Civil and Environmental Engineering University of Washington.

California’s climate. Sierra Nevada snow depth, April 13, 2005 April 1 snowpack was 3 rd largest in last 10 years cm snow Source:

Alan F. Hamlet, Philip W. Mote, Dennis P. Lettenmaier JISAO/CSES Climate Impacts Group Dept. of Civil and Environmental Engineering University of Washington.

Estimating Changes in Flood Risk due to 20th Century Warming and Climate Variability in the Western U.S. Alan F. Hamlet Dennis P. Lettenmaier.

JISAO Center for Science in the Earth System Climate Impacts Group

Hydrologic Implications of 20th Century Climate Variability and Global Climate Change in the Western U.S. Alan F. Hamlet, Philip W. Mote, Dennis P. Lettenmaier.

Challenges in western water management: What can science offer?

Hydrologic implications of 20th century warming in the western U.S.

JISAO Center for Science in the Earth System Climate Impacts Group

Hydrologic Implications of 20th Century Warming in the Western U.S.

Alan F. Hamlet Prof. Dennis P. Lettenmaier (Chair) Phd Final Exam

Hydrologic Implications of 20th Century Warming in the Western U.S.

Climate impacts on the Pacific Northwest environment: Hydrology and water resources Dennis P. Lettenmaier Department of Civil and Environmental Engineering.

Trends in Runoff and Soil Moisture in the Western U.S

Hydrologic Forecasting

Long-Lead Streamflow Forecast for the Columbia River Basin for

Effects of Temperature and Precipitation Variability on Snowpack Trends in the Western U.S. JISAO/SMA Climate Impacts Group and the Department of Civil.

Long-Range Hydropower Forecasts for the Columbia River, Colorado River, and Sacramento/San Joaquin Systems Alan F. Hamlet, Andrew Wood, Nathalie Voisin.

Hydrologic Changes in the Western U.S. from

Evaluating Recent 20th Century Changes in Cool Season Precipitation and Hydropower Variability in the Western U.S. in the Context of Paleoclimatic Reconstructions.

UW Hydrologic Forecasting: Yakima R. Discussion

Presentation transcript:

The West’s declining snowpack: is global warming to blame? Philip Mote Climate Impacts Group University of Washington

20th century decline in NH snow cover R.D. Brown, J. Climate, 2000

Trends in snowpack Use VIC and met data to evaluate trends, roles of temperature and precipitation

Snow course data Collected primarily ~April 1 beginning in 1915 (most in 1940s), added other months Purpose: streamflow forecasting Administered by USDA Natural Resource Conservation Service Mostly discontinued, some replaced by SNOTEL

Snow course ???

Courtesy USDA NRCS Data: NRCS CA DWR BC SRM

Courtesy USDA NRCS

decrease increase Trends in April 1 SWE, snow courses 73% – trends Large – trends PNW Some + trends SW

decrease increase Trends in April 1 SWE, Relative to 1950 value

Former snow course location

Relating SWE to climate data US Historical Climate Network (USHCN) Use nearest 5 stations to form reference time series T(t) and P(t) Regression: SWE(t)=a T T(t) + a P P(t)+  (t)

At almost every USHCN station, winters warmed + signs: warming but not statistically significant

Winters wetter in much of the West Drier in some of Northwest (PDO)

Correlations between Nov-Mar climate and Apr 1 SWE X-direction: precip Y-direction: temp Coldest locations insensitive to temperature Cascades very sensitive

April 1 SWE trends, a P a T

April 1 SWE trends, a P a T

SNOTEL data: cold-season melt events vs Apr 1 SWE

Relative trends

Declining snowpack in the Cascades From a simulation with a hydrology model

relative trends vs DJF temperature Obs VIC

Trends in April 1 SWE in VIC simulation with fixed precipitation

As the West warms, winter flows rise and summer flows drop Figure by Iris Stewart, Scripps Inst. of Oceanog. (UC San Diego)

Simulation of future snowpack with VIC hydrologic model Trend in total April 1 snowpack, : -11% Courtesy Andrew W. Wood, University of Washington

SNOTEL data: cold-season melt events vs Apr 1 SWE Figure by Martyn Clark, Univ. of Colorado

Regional average April 1 SWE Obs o VIC x

Changes in SWE vs changes in precip 1930s to 1990s to 1990s Obs SWEVIC SWEPrecipObs SWEVIC SWEPrecip Cascades-14%+1%+4%-29%-16%-5% Rockies+11%+2%+9%-16%-9%+1% California+3%-14%+10%-2%-25%-1% Interior+9%-6%+10%-22%-18%+2%

Trends/15yr in snow days in Switzerland From Scherrer et al., GRL 2004

Trends in Swiss snow days attributed to temperature and precipitation precip and temp attributions; contour lines indicate the sum. Attribution of trends shown by pseudo vectors; altitude and latitude From Scherrer et al., GRL 2004 days/42 yrs.

Conclusions Observations show substantial declines in western snowpack; corroboration with VIC suggests they are real and largely temperature-driven Cascades, N. Calif most temp-sensitive Large increases in precipitation have offset warming in some places Is global warming causing the decline? Too soon to tell.