Deep ocean observatories

Background

The global Ocean is constantly changing. Much of this is due to natural variability, but there is evidence that man is tipping the delicate balance of this complex system. This is likely to change oceanic nutrient inventories with adverse effects on the functioning of marine ecosystems and global circulation patterns. We need to monitor closely the changing properties of the oceans if we are to understand the consequences of these shifts. This demands a continuous stream of high quality data on climatically and ecologically relevant variables at a number of key locations. A high temporal resolution of the data set is essential to:

• Understand short-term variation and ecosystem dynamics

• Capture episodic events such as phytoplankton blooms that have profound effects on the functioning of the oceans

• Understand long-term variation and climatic trends

This Fact Sheet introduces the importance of deep ocean observatories in the current international effort to monitor the oceans. The EUR-OCEANS network supports the integration of 9 deep ocean observatories and promotes co-ordinated research between member states. This work will be continued and enhanced by a FP7 European project EuroSITES. All deep ocean observatories identifiedwithin EuroSITES are part of an international programme called OCEANsites which monitors key regions of the globe from the sea floor to the atmosphere.

Map to show the location of 9 deep-ocean observatories forming the EuroSITES network. The background shows SeaWIFS satellite chlorophyll distribution. See www.eurosites.info for more information.

Deep ocean observatories: taking the pulse of the ocean

Ocean observatories form an integral part of monitoring the marine environment. They record key variables at fixed geographical locations in the ocean and provide in situ measurements from the surface to the seafloor every few hours over long periods. This gives a perspective of time to the ocean data and allows scientists to factor out everyday variation and detect both episodic events such as phytoplankton blooms and long-term trends in the ocean such as increasing temperatures over a decadal time scale. The high resolution data allows more accurate models to be produced to understand the short-term variability in the oceans including ecosystem dynamics and nutrient cycling. Such models will help predict future changes in the oceans and their feedback effects on our climate.

EuroSITES: A step towards integration

EuroSITES is a FP7 Collaborative Project which focuses on in situ long-term time series ocean observatories (www.eurosites.info). EuroSITES aims to integrate and enhance 9 existing deep (>1000 m) ocean observatories into a coherent European network, coordinated by 7 member states and Cape Verde. The network will encompass the ocean interior, seafloor and subseafloor and establish a pre-operational network with the vision of an operational network in the future. All selected sites have minimal coastal input and can be considered as a model for many open-ocean processes. The integration of these sites is currently supported by EUR-OCEANS but will be continued through EuroSITES.

What are ocean observatories?

Ocean observatories measure properties of the seawater such as temperature, salinity and carbon dioxide. They can continuously record data every few hours for weeks, months and even years. Observatories are typically made of a single column of strong wire stretching from the sea surface to the sea floor. Scientific instruments, sensors, are attached in clusters like mini constellations all the way down the wire. The equipment remains submerged in seawater transmitting information by satellite or storing information inside the sensor until it is picked up by scientists venturing out to sea.

Why do we need long-term monitoring of the oceans?

Observing the oceans is one of the most basic and yet vital ways to understand how our oceans function and how they are changing in order to be able to predict future trends. We need these measurements because the global Ocean is a powerful force in regulating our climate. Ocean data that is transmitted in ‘real-time’ by satellites can allow scientists to detect changes as they happen. This is vital to provide early warning of phenomena such as hurricanes and tsunamis. Data from ocean observatories also provide information on longer-term trends in the climate. For example, some of our global emissions of carbon dioxide get locked away in deep ocean water masses helping to slow down global warming. Measuring the changing levels of carbon dioxide in the oceans over long periods of time gives us clues to how much carbon dioxide the waters can hold, and for how long. Data for variables such as temperature and salinity can also provide information on how the distribution of fish stocks may change and how our fishery strategies change as a result.

What is the future for observing the ocean?

The future for ocean observation in Europe is to provide coordinated, representative monitoring at selected sites/regions from the ocean interior to the seafloor and subseafloor. Research and development must also continue to create more sophisticated sensors to measure more complex properties of the oceans along with adaptive sampling of environmental events. This is essential so that data can be provided to users on time scales from instantaneous real-time hazard warning to long term archiving of data for tracking global change. These data will ensure that the correct management, conservation and mitigation of global change is carried out. This has implications for policy makers, production industries (e.g. fisheries, agriculture) service industries (e.g. insurance) and society at large.

See Also

For other links on deep ocean observatories www.noc.soton.ac.uk/doo/

The main author of this article is Souza Dias, Francisco Please note that others may also have edited the contents of this article. Citation: Souza Dias, Francisco (2012): Deep ocean observatories. Available from http://www.coastalwiki.org/wiki/Deep_ocean_observatories [accessed on 23-11-2024] For other articles by this author see Category:Articles by Souza Dias, Francisco For an overview of contributions by this author see Special:Contributions/Francisco