| The article analyses the influence of the surface wave on the mixed layertemperature variation through adding the effect of wave into the mixed layertemperature equation and the ocean circulation model HYCOM as a boundarycondition. And analysed the effect’s temporal and spatial distribution characteristicsand its significance.Based on the analysis of mixed layer temperature equation and the conclusions ofthe Stokes drift that induced by the wave affecting the mean current, mass transportand energy transfer process, the article points that the Stokes drift has contribution tothe convection-heat transport term in the mixed layer temperature equation.Therefore, the mixed layer equation is modified in this article, the convection-heattransport term induced by the wave is input to the temperature equation. Accordingto the modified temperature equation, the dimensional analysis method is used toanalyze the convection-heat transport term induced by mean current, theconvection-heat transport term induced by wave, the heat flux term and the verticalturbulence term in the equation. From that, the importance of the wave effect ondimension is clear, the effect of wave in high and mid latitude area in north andsouth hemisphere is significant, which can get the equal magnitude with theconvection-heat transport term induced by mean current and the heat flux term. Thenthe data simulated by the model HYCOM and WW3are used to make thequantitative calculation for four terms in temperature equation and use the results toanalyse the spatial distribution characteristic, the seasonal variations feature ofevery terms and study the importance of wave effect. In area of high latitude insouth and north hemisphere （40°N-60°N，40°S-60°S）, the value of wave effect arebigger then the low latitude area. In the area of Antarctic Circumpolar Current thebiggest positive value of wave effect termTs can reach to 0.23×10-6℃/s（0.6℃/month）, the biggest negative value can reach to0.22×10-6℃/s（0.57℃/month） and the annual mean value of global meanTs is0.0992×10-6℃/s（0.26℃/month）. The global meanTs have clear season variation,that in summer and autumn that for the north hemisphere the value ofTs are morebigger than in winter and spring. The studying reveals that in the high latitude areain south and north hemisphere, the convection-heat transport induced by the wave isvery significant compare to that induced by the mean current in the upper ocean. Thebiggest ratio ofTs andTc （the mean current effect term） is present on the64°Slatitude line, the value reach to50%, that mean the effect of wave can reach to halfof the effect of the mean current. In40°S-60°S areas the mean ratio is40%, in40°N-70°N area the mean ratio is30%. In the low latitude area the ratio ofTsandTc is small compare to that in high latitude area, but the mean value also canreach to20%. After adding the wave effect into the temperature equation, the globalmean change of temperature variation rate in the mixed layer is bigger than6%andin the area of ACC the mean variable quantity almost reach10%. In July andOctober the mean variable quantity in area of ACC can reach to15%. The resultsprove the importance of wave for the mixed layer temperature. Although the effectof wave is not the dominant role in the mixed layer temperature field, but theconvection-heat transport term induced by wave can not be ignored during themixed layer temperature variation.Furthermore, the article adds the Coriolis-Stokes force that induced by theStokes drift into the model HYCOM as a boundary condition to simulate the SSTand test the influence of wave on the temperature in the upper ocean. Theexperiment include two sets: the first experiment does not include the effect of wave;the second experiment includes the effect of wave. The Argo data in2001in fivedifferent space location in the Pacific are used to make compare with the results oftwo experiment. The comparison reveals that the SST simulated by the HYCOM with the wave effect are more close to the observed data than that without the waveeffect, that prove the authenticity and the importance of the wave effect on thetemperature in the upper ocean.The ECMWF ERA-40data set is used to study the low frequency variance ofthe significant wave height anomalies in the area of ACC. The results demonstratethat the wave field in the area of ACC have the low frequency signal like theACW（Antarctic Circumpolar Wave）, which have obvious4-5years period and showclear eastward propagation in1985-1995time series. In addition, the significantwave height anomalies and the SST anomalies are correlative, the wave signal leadthe SST signal, which reveal the possible effect of surface wave on the long periodSST anomalies variation. |
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