240 figure 1The coastal ocean is an intricate system that forms the boundary between the land and the deep ocean. This environment consists of tightly linked chemical and biological processes that coexist in a causal relationship with complicated flow dynamics. As the water depth decreases, physical forcing shifts from density gradients to turbulent mixing and frictional forcing along surface, bottom, offshore, and inshore boundaries. While the deep ocean experiences independent air-ocean and ocean benthos interactions, the benthos of the shallow ocean affects the surface layer and in turn alters exchange processes with the atmosphere. In addition, tidal oscillations interacting with low frequency features along the offshore boundary influence cross-shelf exchange with the deep ocean. The near shore boundary is subject to freshwater outflow that produces time-dependent buoyant flows and coastal fronts. Wind forcing is critical to coastal ocean flow and can quickly change the dynamics resulting in the generation of large wave disturbances greater than or of the same magnitude as the underlying low frequency current. The physical habitat characteristics of the coastal ocean are highly variable in space and time and play a critical role in coupled biological and chemical processes that define the ecosystem itself.

 

240 figure 2Within the context of this highly variable system are processes that have significant implications on the hydrographic and oxygen characteristics of the water column. The spatial and temporal variability of these fields can cause dramatic changes to water quality and in turn the health of the entire ecosystem. Both the New Jersey Department of Environmental Protection (NJDEP) and the Environmental Protection Agency (EPA) – Region II have prioritized monitoring the coastal waters off New Jersey in their long-term strategic plans as an essential component of the decision-making process. Of particular interest are the spatial and temporal characteristics of dissolved oxygen (DO). Hypoxic and anoxic conditions ripple through the entire ecosystem causing fish kills and potentially large disruptions to local and remote food webs. In response to this need, we have put together a program to augment existing monitoring with targeted deployments of glider Autonomous Underwater Vehicles (AUVS) equipped with sensors to map coastal hydrography and dissolved oxygen conditions in near-real time along the New Jersey inner-shelf.