CROSSING SWELL AND ORIGINS: GLOBAL VIEW FROM ASAR WAVE MODE FIREWORKS

摘要

Crossing swell, is a complicated sea state characterizedrnby the co-existence of swell systems generating fromrndifferent swell origins. Although many investigationsrnhave focused on the global swell climatology, ourrnunderstanding of global statistical distribution for therncrossing swell is still limited. In this paper, we present arnglobal view of crossing swell using 10-years SyntheticrnAperture Radar (SAR) derived directional swell spectrarnfrom Envisat ASAR in Wave Mode from 2003 to 2011.rnIn contrast to analyze the directly but occasionally SARrncaptured sea state of crossing swell, we employ anrnapproach of propagating observed swell takingrnadvantage of the internal consistency of swells. Resultsrnreveal three dominated crossing swell areas termedrn“crossing swell pools”, in Pacific, Atlantic and IndianrnOceans. The pool in Atlantic Ocean shows a relativernstable behaviour for all seasons, in contrast to the one inrnIndian Ocean with seasonal occurrence and the one inrnPacific Ocean shrinking during boreal summer. Thernsources of the crossing swell are also inferred fromrnASAR wave mode data, and its global distributionrnanalysis results indicate good agreement with thernseasonal variation of crossing swell pools.