Impactsofregionalseasurfacetemperature(SST)anomaliesontheinterdecadalvariationofthecross-equatorialflows(CEFs)inEasternHemispherearestudiedusingnumericalsimulationswithaglobalatmosphericcirculationmodel(NCARCAM3)drivenwith1950-2000monthlySSTsindifferentmarineareas(theglobe,extratropics,tropics,tropicalIndianOcean-Pacific,andtropicalPacific)andERA-40reanalysisdata.Resultsshowthatallsimulations,excepttheonedrivenwithextratropicalSSTs,cansimulatetheinterdecadalstrengtheningofCEFsaroundSomali,120oE,and150oEthatoccurredinthemidandlate-1970s.AmongthosesimulatedCEFs,theinterdecadalvariabilityinSomalianditsinterdecadalrelationshipwiththeEastAsiansummermonsoonareinbetteragreementwiththeobservations,suggestingthatchangesintheSSTsoftropicaloceans,especiallythetropicalPacific,playacrucialroleintheinterdecadalvariabilityofCEFsinSomali.TheinterdecadalchangeofCEFsinSomaliishighlyassociatedwiththeinterdecadalvariationoftropicalPacificSST.Astheinterdecadalwarmer(colder)SSThappensinthetropicalPacific,a'sandwich'patternofSSTanomalies,i.e.'+,-,+'('-,+,-'),willoccurintheeasterntropicalPacificfromnorthtosouthwithapairofanomalousanticyclone(cyclone)atthelowertroposphere;thepairlinkstoanotherpairofanomalouscyclone(anticyclone)inthetropicalIndianOceanthroughanatmosphericbridge,andthusstrengthens(weakens)theCEFsinSomali.
