The Mid-Atlantic Bight Cold Pool, Part-1: Glider Observations

During summer, distinctive, bottom-trapped, cold water mass of remnant local and remote winter water called Cold Pool Water (CPW) resides as a swath over the mid to outer continental shelf throughout much of the Middle Atlantic Bight (MAB). This evolving CPW is important because it strongly influences the ecosystem, including several important fisheries.  Thus, there is a priority to better understand the relevant ocean processes and develop CPW forecast capability.  Over the past decade, repeated high-resolution Slocum glider measurements of ocean water properties along a New Jersey cross-shelf transect have helped to define the variability of the CPW structure off New Jersey. More recently the Mid-Atlantic Regional Association Coastal Ocean Observing System-supported ocean gliders have occupied a series of along-shelf zigzag trajectories from Massachusetts to New Jersey and New Jersey to Maryland. The comprehensive set of March through November 2007 glider measurements has been used to define the annual evolution of the 10^oC Cold Pool in terms of its distribution and water properties. Here we highlight July through October 2007 general warming and salting of the Cold Pool at rates of approximately 1^oC per month and 0.06 psu per month. The nominal 100m lateral resolution of the glider measurements enabled us to define the footprint of the 10^oC Cold Pool. Assuming a 30m upper layer depth, we estimated Cold Pool volumes varying from 4099 km³ in summer 2007 to 2391 km³ in autumn 2007.