Fresh WAys of Targeting and Employing Robotic Systems (FreshWATERS)

Ocean observations are key to understanding the present climate, and improving future predictions. While satellite observations can estimate ocean surface circulation at broad scales, the smaller scale dispersal and transport in narrow regions (e.g., of freshwater in coastal areas around Greenland) are difficult to observe. These regions, however, can have a remarkably large effect on the global ocean circulation, particularly as Greenland and the Arctic appear to be melting at accelerating rates. Surface drifters are small, autonomous floats which travel with ocean currents and transmit their location to a base station via communications satellites. These drifters give an accurate, local measurement of ocean currents.

While drifters themselves are relatively inexpensive, deploying them to remote regions requires the use of global class research vessels. These ships are expensive to operate, and are prohibitively expensive for repeated deployment over longer periods (e.g., an annual cycle). This limits the effectiveness of the mapping, particularly as the currents in many regions of the oceans vary seasonally.

This project proposes an alternative: the concept of the balloon-borne drifter. Attaching each drifter to a gas balloon (similar to the commonly used latex weather balloons) means that it can be launched from land, fly to a target area (taking advantage of high-altitude winds), and then make a gentle splashdown at a target location. Using forecasts of high-altitude winds several days in advance, can give us a close approximation of where a simple balloon (and its drifter payload) will splash down. Moreover, adding an altitude control system to a balloon will enable an automated flight planning system to select the altitude to fly at, thus steering the balloon. The on-board altitude control system will also allow a controlled descent for gentle release of the payload (the drifter). The aim of FreshWATERS is to design the on-board altitude control system and the flight simulator/planner for the balloon.

To maximize the scientific effectiveness of the FreshWATERS system, we will simulate the release of a fleet of drifters over a target region in the ocean. By testing these deployments in an ocean simulation, we can better prepare for subsequent 'real' deployments. In this case, the Labrador Sea, between Greenland and Canada, is a site of special interest: it is both remote and difficult to access by global class ships, is a region where satellite measurements of ocean currents are insufficient to capture the scales at which the ocean varies, and where climate simulations have predicted that freshwater influx can have an impact on North Atlantic and, indeed, global ocean circulation. With this case study, we will be able to fine tune the FreshWATERS system, putting into place all the ingredients of the next stage: the development of a commercially viable and scientifically powerful new way of understanding the physics of the world ocean.

The major impact of FreshWATERS will be on the future potential of the developed technology.

FreshWATERS has future potential for economic and societal impacts with more effective disaster response.

Oil spills, such as the Deepwater Horizons disaster in the Gulf of Mexico, have, in the past, seen extensive deployments of drifters and they have proven their effectiveness in terms of monitoring and predicting the spread of surface contaminants. It is envisaged that FreshWATERS will offer benefits here in terms of the most important aspect of such operations: deployment speed. Whether launches take place from oil platforms, ships participating in the relief effort or from land, balloon-borne delivery has to potential to cover very large areas very quickly (with the the optimization algorithm built into the campaign planner running under a set of constraints designed to ensure flight path deconfliction with aircraft participating in the disaster response). Such time savings translate into increases in the effectiveness of response measures, reducing the environmental impact of the spill.

FreshWATERS also provides potential for a better understanding of future climate. The broad class of science questions FreshWATERS proposes to answer has a direct link to understanding future climate, with its well-known immense societal implications. With discontinuities and high sensitivities to forcings commonly encountered in ocean circulation models, even marginal improvements in accuracy could have a significant impact on predicting the most serious effects of climate change.

On the immediate timescale (that is, the 12 months of the proposed project) the key non-academic beneficiaries will be commercial providers of oceanographic observation equipment, who will gain a perspective into the potential of this new technology, with the outcomes of FreshWATERS allowing them to make technology investment decisions for the main (TRL 4 to 9) development phase. It is in this spirit that we welcome the involvement of Planet Ocean Ltd throughout the duration of the proposed project.

During and immediately following the FreshWATERS programme, we will have immediate impact on the public by publicising visual details of the virtual balloon-launch campaigns on the UoS physical oceanography blog (available to the public) and the UoS oceanography Facebook page. In addition, we plan to publicise the technological potential both to the oceanographic community through presentations at conferences, e.g. the EGU general assembly, and also to the offshore industry at the next Ocean Business (a conference for ocean technology and offshore survey), to be held in 2017 at the National Oceanography Centre. We will also use the National Oceanography Centre Ocean and Earth Day (held annually in March) to provide an interactive display (typically over 1000 visitors including school children and the general public).