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Internal and external variability of MOC in the Kiel Climate Model (ECHAM5/NEMO) Wonsun Park & Mojib Latif Leibniz Institute of Marine Sciences, Kiel. Internal MOC variability Multidecadal to Multicentennial scales External solar forced variability Idealized experiments. - PowerPoint PPT Presentation
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Internal and external variability of MOC in the Kiel Climate Model (ECHAM5/NEMO)
Wonsun Park & Mojib LatifLeibniz Institute of Marine Sciences, Kiel
THOR Annual Meeting, Paris, 25-26 November 2009
• Internal MOC variability•Multidecadal to Multicentennial scales
• External solar forced variability•Idealized experiments
The Kiel Climate Model (KCM)ECHAM5 (T31L19), NEMO (0.5-2°)
Park et al. 2009 J. Clim.
Atlantic MOC(ctrl, 4000yrs)
Park and Latif 2008 GRL
MOC mode separation
LP 90yrs
BP 30-90yrs
SAT response to MOCMulticentennial vs. Multidecadal
Sea ice response to MOC
SH ice vs. MOC
SH Ice extent vs. MOC
LP 90yrs:
centennial to multicentennial
LP 185yrs
BP 90-185
Freshwater and Sea ice threshold
Park et al. in preparation
SSS
Climate impacts
Surface temperature SLP and wind stress
Park et al. in preparation
Millennial solar forcing experiments1. Solar forcing integration (4200a)
: periodic (P=1000a, ±2W/m2)2. ECHAM5/MLO simulation (2000a)
1000 years
4W/m2
Northern Hemisphere temperatureresponse to external solar forcing
Jones and Mann (2004) reconstruction
Latif et al. 2009 Met. Zeit.
Jones and Mann (2004)
MOC feedback onto NH-SAT
North Atlantic response
Summary1.Multidecadal variability is originated in the
North Atlantic, whereas multicentennial variability is driven in the Southern Ocean.
2.Multicentennial Southern Ocean variability is related to the convective activities associated with sea ice capping threshold.
3.SO multicentennial signal is advected the North Atlantic, and provides stabilization (salinity) effect.
4.The MOC is strongly phase-locked to the external solar forcing, and provides a strong negative feedback on the NH-SAT.