Intensive surveys of the Azores Front: 1. Tracers and dynamics

DL Rudnick, JR Luyten - Journal of Geophysical Research …, 1996 - Wiley Online Library
DL Rudnick, JR Luyten
Journal of Geophysical Research: Oceans, 1996Wiley Online Library
The hypothesis that fronts are sites of active subduction is examined using density,
temperature, salinity, and horizontal velocity data from a trio of surveys of the Azores Front
done in May 1991 and March 1992. These surveys were made using a SeaSoar equipped
with a conductivity‐temperature‐depth profiler and a shipboard acoustic Doppler current
profiler. The potential density and potential voracity indicate that dense water from the north
side of the front may be sliding down beneath the surface outcrop. This apparently …
The hypothesis that fronts are sites of active subduction is examined using density, temperature, salinity, and horizontal velocity data from a trio of surveys of the Azores Front done in May 1991 and March 1992. These surveys were made using a SeaSoar equipped with a conductivity‐temperature‐depth profiler and a shipboard acoustic Doppler current profiler. The potential density and potential voracity indicate that dense water from the north side of the front may be sliding down beneath the surface outcrop. This apparently subducting isopycnal has a great deal of temperature and salinity variability. Horizontal velocity is nearly parallel to isopycnals, indicating that the time rate of change and vertical advection must be small. The thermal wind balance is observed to be valid, especially in the region of the largest horizontal density gradients. Shear at the base of the mixed layer is likely due to near‐inertial motions. The potential vorticity is dominated by the planetary vorticity, except at the front, where vertical shears (the tilting term) become large. The tilting term acts to reduce the magnitude of the potential vorticity at the front, in agreement with simple theoretical models. The magnitude of the tilting term is similar to the total vorticity in the seasonal thermocline.
Wiley Online Library
以上显示的是最相近的搜索结果。 查看全部搜索结果