Infrared Remote Sensing of Surf-Zone Eddies
Infrared Remote Sensing of Surf-Zone Eddies
复制标题
冲浪区涡流的红外遥感
DOI：
10.1109/jstars.2013.2257695
复制
发表时间：
2013
影响因子：
5.5
通讯作者：
W. David Miller
中科院分区：
文献类型：
--
作者：
G. Marmorino;Geoffrey B. Smith;W. David Miller
首次使用机载红外图像来调查沿沿着均匀海滩发生的冲浪区涡旋的特征。涡流被发现有直径为100至150米，沿岸间距约375米（冲浪区宽度的2.5倍），和寿命为40分钟或更长。漩涡以约0.3至0.5 m/s的速度沿海岸移动，距离海岸线约1.3冲浪带宽度。还观察到涡旋直接向离岸移动，距离海岸线两个冲浪区宽度。涡流内的细尺度热结构包括~ 6米宽的冷斑，可能是底部诱导湍流的表面印记，以及一个小的（<10米宽）“冷核”，可能是由径向向内的表面流积累的表面活性剂。通过表面活性剂浮油的流动变形增强了涡流的可视化。特别是，狭窄的浮油似乎被漩涡卷起，形成类似于自由漩涡的螺旋。从这个意义上说，这些近岸涡旋类似于在合成孔径雷达和太阳反辉图像中看到的海洋次中尺度“螺旋涡旋”。
Airborne infrared imagery is used for the first time to investigate characteristics of surf-zone eddies, occurring along an along-shore uniform beach. Eddies are found to have diameters of 100 to 150 m, an alongshore spacing of about 375 m (2.5 times the surf-zone width), and lifetimes of 40 min and longer. Eddies travel alongshore at speeds of ~ 0.3 to 0.5 m/s, at a distance from the shoreline of about 1.3 surf-zone widths. Eddies are also observed to move directly offshore, two surf-zone widths from the shoreline. Fine-scale thermal structure within an eddy includes ~ 6-m-wide cold patches, possibly the surface imprints of bottom-induced turbulence, and a small (<; 10-m wide) `cold core', likely from accumulation of surfactant by radially inward surface flow. Visualization of an eddy is enhanced through flow deformation of surfactant slicks. In particular, narrow slicks appear to be wound-up by an eddy into spirals similar in form to those of a free vortex. In this sense, these nearshore eddies resemble ocean sub-mesoscale `spiral eddies' as seen in synthetic-aperture radar and sunglint imagery.