Extratropical control of recent tropical Pacific decadal climate

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Extratropical control of recent tropical Pacific decadal climate Powered By Docstoc
					  Atlantic-Pacific Teleconnection in
  Response to a weakening of the
   Atlantic Meridional Overturning
             Circulation
                       Lixin Wu
           Physical Oceanography Laboratory
               Ocean University of China
                    Qingdao, China

Collaborators:
Chun Li, Chunxue Yang, Changfang Fang, OUC
Shang-Ping Xie, IPRC
     Atlantic-Pacific
Extratropical and Tropical
     Teleconnection
    Winter(JFM) Geopotential Height




      H
                                  H
L
                              L

      H                           H



Z850                          Z250
Surface Wind and Air Temp.             Precipitation




                 Mild and Wet Winter
Early Winter (OND) Atmospheric Response




            L

    H


        L



    Z850                         Z250
FOAM Experiment




(Lixin Wu, Feng He and Zhengyu Liu, 2005, GRL)
Tropical Atlantic-Pacific Bridge

           FMA




            JJA




            OND
South Atlantic Forcing



                         FMA




                         JJA




                         OND
Predictability


                 FMA




                 JJA




                 OND
Tropical Atlantic-Pacific Bridge


                       Low
                              warm
  Water-Hosing Experiment:
Atlantic-Pacific Teleconnection
            CTRL         Water-Hosing

             AMOC “ON”      AMOC “off”
     10Sv




                   ON
SV




      Collapse            Recovery

                 OFF

                          Year
 Seasonality
 Of Atlantic
 Response

Two questions:

(1) NA-TA Atmos. Tele.

(2) Ocean Heat Transport
Seasonal Response of Extratropical Atmospheric Circulation




 Quasi-
baratropic




Baroclinic
Extratropical influence on the tropics through Atmospheric teleconnection

       No Coupling in the NA                   Coupling in the NA
          Heat Flux, SST and Surface Wind




year1   year2     year3       year4    year5         year6




          year7      year8     year9        year10
MJJ




ASO




NDJ
Eqautrorial
Pacific
Annual
Cycle



              No coupling in the tropical Atlantic
          Seasonal response of North Pacific




No coupling in the NA      No Northern hemispheric atmospheric Tele.
Does tropical Atlantic matter for the Northern hemispheric teleconnection?
Extratropical-tropical Pacific Teleconnection
      Coupled Propagation Mechanism:
          Coupled equatorward propagation
          due to wind-evaporation feedback




                                                T
                      U

                                                         ITCZ

                                                           EQ
       West                                       East
Xie and Philander 1994; Wu et al. 2006 (Climate Dynamics, in press)
                     +NAO
Arctic Oscillation

				
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posted:4/13/2013
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