Upper Ocean Climate and Variability in the CCSM2

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Upper Ocean Climate and Variability in the CCSM2

• Michael Alexander
• Antonietta Capotondi and James Scott
• NOAA-CIRES
• Climate Diagnostics Center

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Overview A Broad Survey

• Long term means
• Qnet, MLD, SSS, Surface Currents
• Large suite of diagnostics on web page
• http//www.cgd.ucar.edu/csm
• Follow control run link
• Variability
• Standard deviation of SST z20
• Survey of Upper Ocean Processes
• Reemergence
• Subduction
• ENSO Teleconnections
• Indian Ocean variability

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Annual Mean Net Surface Heat Flux (Wm-2)
CCSM
CCSM-NCEP
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March Mixed Layer Depth (m)
CCSM
Levitus (Obs)
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Annual Mean Sea Surface Salinity (ppt)
CCSM
CCSM-Levitus
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Annual Mean Zonal Surface Currents (cm s-1)
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Annual Mean Zonal Current at 151ºE
CCSM
Depth (cm)
NCEP Pacific Ocean Data Assim
Depth (cm)
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Thermocline Depth VariabilityStandard Deviation
of 20ºC Isotherm
CCSM
NCOM 1958-1997
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Monthly SST Standard Deviation (C)
CCSM
NCEP
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Annual Cycle of Monthly Mean Standard
Deviation of SST along 42ºN
CCSM
NCEP
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Annual Cycle of Temperature (ºC) MLDCentral N.
Pacific Region 26ºN-42ºN,164W-148W
CCSM
Levitus
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Reemergence Lead-lag Correlations between the
Temp(month,depth) with Temp at the Base Point
(Aug-Sep,50-90m)
Central North Pacific Region
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Local Lead-lag Correlations along 42ºN between
SST and Temp anomalies at the Base point
SST Lags
SST Leads
Basepoint Aug-Sep, 55-85M
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Subduction in the Central North
PacificTemperature Anomalies Ave 170ºW-150ºW
Contours LTM Annual Temperature
Shade Annual Anomalies 3-Year Ave
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ENSO TeleconnectionsSLP(NDJ) SST(FMA)
Regressed on Niño Index (NDJ)
CCSM
NCEP
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Indian Ocean Variability SST EOFs 12
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Summary

• Many upper ocean process are simulated reasonably
  well
• e.g. Reemergence
• Other processes while present differ somewhat
  from the real world
• e.g. Atmospheric Bridge (ENSO Teleconnections)
• Hope these preliminary findings will motivate you
  to have a closer look.

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Annual Mean SST (ºC)
CCSM
CCSM-NCEP