Given its relative proximity to major metropolitan areas (Seattle, Vancouver and Portland), the shelf of the Washington Coast has been surprisingly under-sampled and is, consequently, less clearly understood than other coastal regions such as the California, Oregon and New England continental shelves. This is at least partly due to the extreme weather conditions encountered in winter months on the Washington shelf, with storm winds regularly hurricane-force and waves occasionally topping 10 m (33 ft). Yet, the Washington Coast holds some of the most commercially-important fishing grounds in the lower 48, and is home to or provides critical habitat to a wide range of marine species. The presence of the Olympic Coast National Marine Sanctuary reflects this ecological importance.
In an effort to close the gap in observations and understanding, we have designed, fabricated and deployed a long-term, real-time mooring system off the Washington Coast---collectively referred to as NEMO (Northwest Enhanced Moored Observatory). This project has been largely possible because of a grant from the Murdock Charitable Trust as well as both funding and field support from NOAA. This real-time mooring system is a novel integration of various sampling platforms to achieve unprecedented observations. The primary mooring is a heavily-instrumented 3500-lb surface mooring (Cha Ba or Quileute for "whale tail") which samples both meteorology (winds, air temperature, rainfall) in addition to ocean properties (salinity, temperature, oxygen, nitrate, chlorophyll, pH, currents, etc.) at various depths. Cha Ba is also instrumented with a pCO2 system to help us better understand changes of CO2 in the ocean and atmosphere.
A second component of this mooring system is a nearby subsurface mooring equipped with a "crawler" or an instrumented platform that travels up and down a cable at regular intervals (2 hours) measuring ocean profiles of velocity, nitrate, oxygen, density, salinity, temperature, chlorophyll and turbidity. Though profiles are conducted less frequently than the rapid measurements on Cha Ba, they have excellent resolution with depth.
One drawback of fixed moorings is that they provide little to no information on spatial variability unless deployed in large numbers. To address this issue, the third component of the mooring system is a Seaglider operated by C. Lee’s Instrumented Observation Platform (IOP) Group at APL. The glider, which does well at capturing spatial variability, is typically programmed to run about 190 km long onshore-offshore transects ending at the two moorings at the onshore endpoint. Although the original glider used to collect these data was lost in March of 2016 due to a vessel strike, we hope to obtain a new glider by 2018.
With funding through the NOAA IOOS Ocean Technology Transfer program, in the summer of 2016 we deployed a harmful algal bloom detection instrument called the Environmental Sample Processor on the subsurface mooring. We have been funded to deploy the ESP again in 2017, with deployments in the spring/early-summer (May-July) and late summer/early fall (August-October). More info at NANOOS Real-time HABS Website.
In October 2016 we deployed a new surface mooring called Winter Cha Ba, which will enable us to carry out year-round observations, field swapping summer and winter buoys in the fall and spring.
- Collect near-continuous, high-quality oceanographic and atmospheric data that will enable us to:
- better understand variability and long-term trends of water properties
- investigate the dominant physical and biogeochemical processes on the shelf
- ground-truth on-going modeling efforts
- Provide real-time data to waterways users, stakeholders and resource managers so they can make informed, timely decisions. This includes:
- providing supporting observations for health and fisheries management decisions, such as real-time DO and HABs observations, and
- providing operational oceanographic observations (e.g. wave height measurements) for waterways users such as recreational and commercial fisheries and the U.S. Coast Guard
- What is the seasonal, inter-annual, and decade-scale variability of water properties on the northern Washington shelf and what are the dominant factors controlling this variability? Specifically, what are the dominant processes controlling seasonal and inter-annual DO and pH variability.
- What are the dominant processes driving the enhanced productivity on the mid Washington shelf.
- What is the role of summertime wind reversals in supplying nutrients to the Washington Shelf?
- What are the sources of water that comprise the mid-shelf water in upwelling and downwelling seasons?
- What is the role of internal waves (waves that travel along the ocean’s density surfaces) in re-distributing nutrients, oxygen and low-pH water?