Predictability and Diagnosis
of Low-Frequency Climate Processes
in the Pacific
Arthur J. Miller
Tim P. Barnett
Daniel R. Cayan
David W. Pierce
Scripps Institution of Oceanography
University of California, San Diego
Niklas Schneider
International Pacific Research Center
University of Hawaii
Department of Energy
Climate Change Prediction Program
Grant DE-FG03-01ER63255
Progress Report
Seattle, Washington
October 19, 2004
Predictability and Diagnosis
of Low-Frequency Climate Processes
in the Pacific
Research Topics
1) The fundamental dynamics of decadal climate variability in the Pacific Ocean,
including predictability and the expected effects of anthropogenic forcing.
2) The techniques of making and evaluating climate predictions,
including initial conditions, surface boundary forcing, and
statistical techniques for diagnosing state-of-the-art GCMs.
3) Regional predictability of natural and forced climate changes over
western subcontinental North America including the coastal ocean.
Addresses a major scientific objective of the BER CCRD:
“accurate prediction of future climate
on decadal to centennial timescales.”
Predictability and Diagnosis
of Low-Frequency Climate Processes
in the Pacific
Recent publications supported by DOE:
Barnett, T. P., D. W. Pierce, M. Latif, D. Dommenget, R. Saravanan, 1999:Geophys. Res. Lett., 26, 615-618.
Barnett, T. P, D. W. Pierce, R. Schnur, 2001: Science, 292, 270-274.
Di Lorenzo, E., A. J. Miller, N. Schneider, J. C. McWilliams, 2004: J. Phys. Oceanogr., in press.
Hidalgo, H.G., D. R. Cayan, M. D. Dettinger, 2004:J. Hydrometeorol., submitted.
Mestas-Nunez, A. M., A. J. Miller, 2004: Progr. Oceanogr., in press.
Miller, A. J., A. J. Gabric, J. R. Moisan, F. Chai, D. J. Neilson, D. W. Pierce, and E. Di Lorenzo, 2004:
In: Global Climate Change and Response of the Carbon Cycle in the Equatorial Pacific and Indian
Oceans and Adjacent Land Masses, Elsevier Oceanography Series, submitted.
Pierce, D. W., 2001: Prog. Oceanogr., 49, 331-352.
Pierce, D. W., 2002: J. Climate, 15, 1295-1308.
Pierce, D. W., 2004: Climatic Change, 62, 389-418.
Pierce, D. W., 2004: Computing in Science and Engineering, in press.
Schneider, N., 2000:.Geophys. Res. Lett., 27, 257-260.
Schneider, N., 2004: J. Climate, 17, 1083-1095.
Schneider, N. and A. J. Miller, 2001: J. Climate, 14, 3997-4002.
Schneider, N. and B. D. Cornuelle, 2004: J. Climate, submitted.
Schneider, N., A. J. Miller and D. W. Pierce, 2002: J. Climate, 15, 586-605.
Schneider, N., E. Di Lorenzo and P. P. Niiler, 2004: J. Phys. Oceanogr., submitted.
Stewart, I., Cayan, D. R., and M.D. Dettinger, 2004: Climatic Change, 62, 217-232.
Stewart, I., Cayan, D. R., and M.D. Dettinger, 2004: J. Climate, submitted.
Yulaeva, E., N. Schneider, D. W. Pierce and T. Barnett, 2001: J. Climate, 14, 4027-4046.
Zhu, C., D. W. Pierce, T. P. Barnett, A. W. Wood, and D. P. Lettenmaier, 2004:Climatic Change, 62, 45-74.
Selected Research Highlights
Since Last DOE CCPP Meeting
• Forcing of the Pacific Decadal Oscillation
(Schneider, also see poster)
• Validating climate model higher-order statistics
(Pierce/Barnett, also see poster)
• Trends in the onset of western U.S. streamflow
and relationship to PDO (Cayan)
• Future changes in California Current circulation
under global warming scenario (Miller)
What Forces the Pattern and Timescales
of the Pacific Decadal Oscillation?
Nov-Mar
PDO: a response of North Pacific SST to
• El Nino
• Aleutian Low
• Transport of the Kuroshio/Oyashio Extension
Schneider and Cornuelle, J. Climate, submitted
Hindcast of annual averaged values of SST: the PDO
Tn = Tn-1 + i Fi,
PDO
Obs.
Reconst.
Autoregressive
model forced by
n
El Nino
Aleutian Low
KOE adjustment to Ekman pumping
Observed
PDO
Observed
NPI
Reconstructed
KOE
NINO3.4
Schneider and Cornuelle, J. Climate, submitted
Validating climate models by comparing
distributions of daily temperature
Colors indicate the
(transformed) skew of
the distribution of daily
average temperature
anomalies, Dec-Jan-Feb
From Pierce, Computing in
Science & Engineering, 2004
See poster for further details.
Trends in Onset of the
Spring Pulse of
Streamflow
• Pulse onset occurs
1-4 weeks earlier in
recent period
• Date of the “center of
mass” of streamflow
also earlier (red) in
snowmelt streams…
• …but later (blue) in
rainfall streams along
the coast (inset)
Stewart, Cayan and Dettinger
J. Climate, 2004
What Controls the
Streamflow Changes?
PDO vs. Local
Temperatures
• Correlation between
streamflow “center of
mass” (minus spring
temperature index) and
PDO index is weak
• Correlation between
streamflow “center of
mass” (minus PDO index)
and spring temperature
index is high
• Local temperatures appear
to control the streamflow
Stewart, Cayan and Dettinger
J. Climate, 2004
Streamflow and temperature anoms: All Stations
Did the 1999 PDO
Reversal Affect
Streamflow Timing?
Epoch differences
• Warm period (1977-1998)
minus early cool period
(1948-1976) streamflow
“center of mass” shows
earlier timing
• Recent cool period
(1999-2000) minus warm
period (1977-1998) also
shows earlier timing
• PDO reversal does not
appear to affect
streamflow timing
Stewart, Cayan and Dettinger
J. Climate, 2004
California Current Circulation
in a Global Warming Scenario
Baseline: NCEP 50-yr climatology
of wind stress and curl
Perturbation: ACPI PCM 2040-2050 climate
minus 1986-1996 climate
downscaled with RSM
California Current Circulation
in a Global Warming Scenario
Baseline: NCEP 50-yr climatology
of surface heat flux
Perturbation: ACPI PCM 2040-2050 climate
minus 1986-1996 climate
downscaled with RSM
Regional SST Changes
in a Global Warming Scenario
Baseline: 1 deg C warming over last Perturbation: Forced by 2040-50 winds and
50 years of CalCOFI data surface heat fluxes, but not BC changes:
SST warmed 0.4 - 0.7 deg C
(Auad, Miller, Pierce, Di Lorenzo, in prep)
Mesoscale Eddy Variance Changes
in a Global Warming Scenario
Baseline: Offshore variance max
increased after 1976-77 shift
(Di Lorenzo et al., 2004)
Perturbation: Forced by 2040-50 winds and
surface heat fluxes, but not BC changes:
variance generally reduced (only 6 yr long run)
(Auad, Miller, Pierce, Di Lorenzo, in prep)
Selected Research Highlights
Since Last DOE CCPP Meeting
• Forcing of the Pacific Decadal Oscillation
(Schneider, also see poster)
• Validating climate model higher-order statistics
(Pierce/Barnett, also see poster)
• Trends in the onset of western U.S. streamflow
and relationship to PDO (Cayan)
• Future changes in California Current circulation
under global warming scenario (Miller)
Department of Energy
Climate Change Prediction Program
Grant DE-FG03-01ER63255
Thanks!