By incorporating the wave-induced Coriolis-Stokes forcing into the classical Ekman layer,the wave-modified ocean surface currents in the northwestern Pacific Ocean were estimated.Thus,the ocean surface currents are the combination of classical Ekman current from the cross-calibrated multi-platform(CCMP)wind speed,geostrophic current from the mean absolute dynamic topography(MADT),and wave-induced current based on the European Centre for Medium-Range Weather Forecasts(ECMWF)Interim Re-Analysis(ERA-Interim)surface wave datasets.Weight functions are introduced in the Ekman current formulation as well.Comparisons with in-situ data from Lagrangian drifters in the study area and Kuroshio Extension Observatory(KEO)observations at 32.3°N,144.6°E,and 15-m depth indicate that wave-modified ocean surface currents provide accurate time means of zonal and meridional currents in the northwestern Pacific Ocean.Result shows that the wave-modified currents are quite consistent with the Lagrangian drifter observations for the period 1993-2017 in the deep ocean.The correlation(root mean square error,RMSE)is 0.96(1.45 cm/s)for the zonal component and 0.90(1.07 cm/s)for the meridional component.However,wave-modified currents underestimate the Lagrangian drifter velocity in strong current and some offshore regions,especially in the regions along the Japan coast and the southeastern Mindanao.What's more,the wave-modified currents overestimate the pure Eulerian KEO current which does not consider the impact of waves,and the zonal(meridional)correlation and RMSE are 0.95(0.90)and 11.25 cm/s(12.05 cm/s)respectively.These comparisons demonstrate that our wave-modified ocean surface currents have high precision and can describe the real-world ocean in the northwestern Pacific Ocean accurately and intuitively,which can provide important routes to calculate ocean surface currents on large spatial scales.

Zhenli HUI;Ying LI;Jia SUN;Long YU;Xia JU;Xuejun XIONG

Shandong Key Laboratory of Marine Science and Numerical Modeling,Qingdao 266061,China;First Institute of Oceanography,and Key Laboratory of Marine Science and Numerical Modeling,Ministry of Natural Resources,Qingdao 266061,China;Laboratory for Regional Oceanography and Numerical Modeling,Pilot National Laboratory for Marine Science and Technology(Qingdao),Qingdao 266237,China

海洋湖沼学报（英文版）

[1]Zhenli HUI;Ying LI;Jia SUN;Long YU;Xia JU;Xuejun XIONG-.Validation and error analysis of wave-modified ocean surface currents in the northwestern Pacific Ocean)[J].海洋湖沼学报（英文版）,2022(04):1289-1303

MADT,drifters,KEO,drifter,Mindanao

Validation,error,analysis,modified,ocean,surface,currents,northwestern,Pacific,Ocean,By,incorporating,induced,Coriolis,Stokes,forcing,into,classical,Ekman,layer,were,estimated,Thus,combination,from,cross,calibrated,multi,platform,CCMP,wind,speed,geostrophic,absolute,dynamic,topography,European,Centre,Medium,Range,Weather,Forecasts,ECMWF,Interim,Analysis,ERA,datasets,Weight,functions,introduced,formulation,well,Comparisons,situ,Lagrangian,study,area,Kuroshio,Extension,Observatory,observations,depth,indicate,that,provide,means,zonal,meridional,Result,shows,quite,consistent,period,deep,correlation,root,square,RMSE,component,However,underestimate,velocity,strong,some,offshore,regions,especially,along,Japan,coast,southeastern,What,more,overestimate,pure,Eulerian,which,does,not,consider,impact,waves,respectively,These,comparisons,demonstrate,our,have,high,precision,can,describe,real,world,accurately,intuitively,important,routes,calculate,large,spatial,scales

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