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Impacts of past and future climate change on Northwest sk


Impacts of past and future climate change on Northwest ski areas. Products ... Region wide increases in area burned are characterized by antecedent drought ... – PowerPoint PPT presentation

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Title: Impacts of past and future climate change on Northwest sk

What weve done the large scale context
  • ENSO
  • A new stable mechanism for ENSO (Thompson
    Battisti 2000, 2001)
  • Observing network studies (Morss and Battisti
  • Review papers (Wallace et al. 1998 Harrison and
    Larkin 1998 Sarachik 1999, 2001 Mote, Sarachik
    Dequé 2000)
  • Mechanisms for termination of events have been
    proposed (Harrison and Vecchi 1999 Vecchi and
    Harrison 2003)
  • Statistical methods for ENSO prediction were
    developed (Johnson et al. 2000

What weve done the large scale context
  • Pacific Decadal Climate Variability
  • Documented the characteristics of tropical
    interannual versus extratropical interdecadal
    Pacific climate variability (Zhang, Wallace and
    Battisti 1997)
  • Established and synthesized strong links between
    interdecadal changes in Pacific salmon production
    and Pacific climate, and in the process named the
    Pacific Decadal Oscillation (Mantua et al. 1997)
  • PDV Review papers (Mantua 2001, Mantua and Hare
    2002, Sarachik and Vimont 2003)
  • Mechanisms for PDV in a coupled climate model
    (Vimont et al. 2001, 2003) and the Seasonal
    Footprinting Mechanism (Vimont et al. 2003)

What weve done the large scale context
  • Named the Arctic Oscillation AO (Thompson
    Wallace 2000)
  • Identified AO links to extreme weather events and
    North Americas climate predictability (Thompson
    et al. 2002 Wallace and Thompson 2002 Thompson
    and Wallace 2001)
  • Identified mechanisms that weaken the
    thermohaline circulation and THC links to the
    Pacific thermocline and ENSO (Kamenkovich et al.
    2003 Kamenkovich and Sarachik 2004 Huang et al.
    2000 Goodman and Sarachik, in review)
  • Established links between tropical intraseasonal
    variability and west coast precip (Bond and
    Vecchi 2003 Vecchi and Bond, in press)

What weve done regional foci
  • Trends in NW temperature, precipitation, and snow
  • Mote, 2003, Can. Wat. Res. J. Mote, 2003,
    Northwest Science
  • Trends in Western North Americas snow,
    temperature and precipitation
  • Mote et al., (in press), Bull. of the Amer.
    Meteorol. Soc.
  • Climate and Western Wildfire
  • McKenzie et al.,2004, Cons. Biol. Gedalof et al.
    (in press), Ecol. Appl.
  • Paleoclimate
  • Gedalof et al. (2003) Paleo PDO reconstruction.
  • Gedalof et al. (in press) Columbia R. flow
    since 1750. JAWRA
  • Strom et al. (2004) NE Pacific SSTs (from
    Geoduck shell growth) to 1850s. Geophys. Res.

Area-weighted Regional Avg1.5 F/century
USHCN stations Circles significant at plt0.05
signs warming but not statistically
significant Area Averaged warming 1.5F/100 yrs
Extrapolations are based on IPCC CO2 scenarios
and observed sensitivity
Relative trends in April 1 snow water equivalent
To appear in BAMS, January 2005
What we plan to do
  • Support regional climate impacts studies
  • Regionally focused climate diagnostics
  • Better quantify links between tropical
    intraseasonal weather and NW precipitation
  • Quantify statistics of extreme temperature (heat
    waves and cold spells), precipitation, and very
    low summer streamflow periods
  • Regional climate modeling and downscaling
  • Downscaling NCEP/CPC seasonal forecasts in
    collaboration with the Scripps ECPC
  • Downscaling IPCC climate change scenarios

What we plan to do
  • Improve hydrologic forecasts
  • Link PNA forecasts to precipitation forecasts
  • Improve 2-week streamflow forecasts with enhanced
    skill in precipitation predictions
  • Improve seasonal streamflow forecasts with
    improved methods for 1st 2 weeks precipitation
  • Examine the predictability of watershed-scale
    hydrologic extremes
  • Do SST-based large-scale drought forecasts have
    skill at regional scales?

What we plan to do
  • Examine Hydroclimate trends for the west from
    data and from a simulation model (VIC) at 1/8
    degree resolution for 1916-2003.
  • Examine timing of snowmelt and streamflow changes
    using VIC and observations
  • Determine causes for observed changes How much
    trend is explained by precipitation changes? How
    much is explained by temperature change? What are
    the local/regional sensitivities to T and P?
  • Impacts of past and future climate change on
    Northwest ski areas

  • Downscaled Data products
  • Historical, seasonal forecasts, and future
    climate change scenarios (access via our Live
    Access Server)
  • Seasonal ENSO forecasts
  • http//
  • PNA-based risk-assessment maps to be used with
    NCEPs long-lead ensemble PNA forecasts

The function of the State Climatologist is to
collect, disseminate, and interpret climate data.
  • Making the global/large scale climate connection
    to regional resource impacts
  • S/I forecasts stream flows and reservoir
    inflows, coho ocean survival rates
  • Climate change scenarios basin-specific
    runoff changes, salmon survival changes, drought
    and fire risk, hydropower, irrigation, fish flow,
    changes in municipal water supplies and demands
  • Paleoclimate and paleo-resource reconstructions
    to better understand natural variability in NW
    climate and resources

Extreme Events Risk Forecasting
  • Experimental 7-14 day extreme weather event risk
    assessment forecasts available for the PNW.
  • Based on observed relationships between the
    probability of certain extreme weather events in
    the US and variations in Pacific North American
    atmospheric circulation pattern.
  • Forecasts include probabilities for
  • Extreme warm/cold days, days with extremely high
    precip, heavy snowfall events
  • Benefit aids extreme events management

High snow events are 2-4 times more likely
during negative PNA than positive PNA, depending
on location
Changes in Simulated April 1 Snowpack for the
Cascade Range in Washington and Oregon
Current Climate
2020s (1.7 C)
2040s ( 2.5 C)
April 1 SWE (mm)
  • Transient SWE simulation from HadCM3 (A2) GCM run
    (with running 10 year average smoothing)
  • Simulated from observed climate shows a declining
    trend of 3KAF per decade (1935-2000)
  • HadCM3 simulated declines 4KAF per decade

Figure courtesy of Matt Wiley and Richard Palmer
at CEE, UW
Climate and Wildfire
  • 1. Climate Matters
  • Region wide increases in area burned are
    characterized by antecedent drought accompanied
    by persistent blocking events
  • 2. Ecology Matters
  • Underlying ecology appears to modulate the
    response to drought and circulation
  • 3. Relationships are non-linear
  • Small changes in mean climate may lead to
    dramatic changes in wildfire activity

Big NW fire year composites