The three-dimensional structure of the nose of a buoyant coastal current.

Shipboard and moored observations in the vicinity of the nose of a coastally trapped river plume were obtained in the spring/summer of 2015 off the Virginia, North Carolina coast. Moored observations included a pair of wirewalkers equipped with CTD’s and Doppler current meters affixed to floats 5-m from the surface that together provided measurements of shear and stratification to within 75 cm of the surface. This was complemented with an extensive mooring array consisting of fixed CT’s and bottom mounted Dopplers at two cross-shore sections along the coast. Shipboard surveys included tow-yo’d CTD profiles and shipboard Doppler Current data that provided measurements of shear and stratification in the vicinity of the nose of the coastal current as it propagated through the mooring array and provided horizontal resolution (<<100m) both in the along shore and cross-shore directions. Together these observations will yield a detailed description of the 3-dimensional structure of a coastally trapped river plume. Analysis presented in this poster will focus on characterizing the structure of the nose region of a buoyant coastal current and assess the relative importance of lateral and vertical shear in driving buoyancy flux to the nose, the spatial structure of shear, stratification and Richardson Numbers in the cross shore and along shore directions and the extent to which vertical shears are in thermal wind balance.