Wind drag in oil spilled ocean surface and its impact on wind-driven circulation  

作　　者：Hui Shen William Perrie Yongsheng Wu 

机构地区：[1]Bedford Institute of Oceanography,Fisheries and Oceans Canada,Dartmouth,NS B2Y4A2,Canada

出　　处：《Anthropocene Coasts》2019年第1期244-260,共17页人新世海岸(英文)

基　　金：supported by the Office of Energy Research and Development(OERD),CSA Data Utilization and Applications Program(DUAP),and Canada’s Ocean Frontier Institute.

摘　　要：The drag coefficient is a key parameter to quantify the wind stress over the ocean surface,which depends on the ocean surface roughness.During oil spill events,oil slicks cover the ocean surface and thus change the surface roughness by suppressing multi-scale ocean surface waves,and the drag coefficient is changed.This change has not been included in the current ocean circulation models.In this study,such change in sea surface roughness is studied by satellite remote sensing via synthetic aperture radar(SAR)data to quantify the changes in the wind effect over the oil-covered ocean surface.The concept of effective wind speed is introduced to quantify the wind work on the ocean.We investigate its influence on the wind-driven Ekman current at the ocean surface.Using observations from the Deepwater Horizon oil spill(2010)as an example,we find that the presence of oil can result in an effective wind speed of 50%∼100%less than the conventional wind speed,causing overestimates by 75%∼100%in the wind driven Ekman current.The effect of such bias on oil trajectory predictions is also discussed.Our results suggest that it is important to consider the effect of changes in the drag coefficient over oil-contaminated areas,especially for largescale oil spill situations.

关 键 词：roughness length drag coefficient oil spill synthetic aperture radar Ekman current 

分 类 号：P73[天文地球—海洋科学]