Australian National Facility for Ocean Gliders ANFOG: Australian National Facility for Ocean Gliders

Basics of an Ocean Glider Related to ARGO floats – but with wings Powered by batteries (C or D cells) Buoyancy engine – pumping oil or water into and out of a bladder changes density of vehicle which causes glider to sink or float Wings provide forward momentum – motion through the water is a saw tooth pattern Control via a rudder or movement of battery pack fore to aft and side to side

Ocean Gliders Description Operation depth ratings 200, 1000, 5000 m Designed for launch, monitor, recover or launch, forget, recover missions Mission duration 15 days – 6 months Speed < 1 kn - typically 0.2-0.5 knts Weight – 50-75 kgs in air Monitored and programmed at surface from control stations located on your desktop. R/T communications at surface via radio link, Iridium, cell, Argos Easily deployed and recovered from small boats or docks by 1 or 2 persons Operations in all weather

Typical Glider “saw tooth” motion

Glider Manufacturers 3 groups in US building vehicles Webb Research – Slocum Glider, Thermal Glider UofW/APL – Seaglider Scripps Institute - Spray Glider (now Bluefin)

Slocum Electric Glider Manufactured by Webb Research, USA

Slocum Gliders – Webb Research

Seaglider UofW / APL

Spray Glider – Bluefin Scripps

Spray Glider - Scripps

Development Timeline 1989 “The Slocum Mission” appears in Oceanography 1990 Office of Naval Technology (ONT) awards Webb Research Corporation contract for development of Slocum prototype 1991 Tests of Slocum prototype and thermal engine in Wakulla Springs FL and Lake Seneca NY 1992 First deployment of the ALBAC glider, a shuttle type glider developed at the University of Tokyo in the lab of Tamaki Ura. The ALBAC design uses a drop weight to drive the glider in a single dive cycle between deployment and recovery from ship. It uses a moving internal mass to control pitch and roll. 1993 Autonomous Oceanographic Sampling Networks paper appears in Oceanography

Development Timeline 1999 Slocum gliders tested at LEO-15 Observatory NJ 1999 Autonomous Ocean Sampling Network (AOSN) I conducted in Monterey Bay, CA to make oceanographic surveys. A prototype Spray operates for 11 days. Three Seagliders were also deployed in the bay. 2000 By this time all three gliders, Spray, Slocum, and Seaglider, have completed 10 day missions 2001 Spray glider makes 280 km section from San Diego 2002 Seaglider travels 1000+ km off Washington Coast. Another Seaglider is deployed for month in storms off shelf near Seward Alaska 2003 January. Deployment of three Slocum gliders in the Bahamas by WHOI. Trials of prototype thermal Slocum conducted by WRC on same cruise

Development Timeline 2003 February. SPAWAR and the Canadian Navy conduct tests in the Gullf of Mexico of 3 Slocum electric gliders. 2003 August – September. AOSN II conducted in Monterey Bay CA. Gliders are used to make extensive oceanographic surveys over a six week period. Twelve Slocum and five Spray gliders are deployed during the experiment, to date the most gliders deployed for one project. 2004 September – November. A Spray glider travels across the Gulf Stream, beginning about 100 miles south of Nantucket, MA and arriving near Bermuda about one month later. The glider travels 600 miles, at a speed of about 0.5 miles per hour or 12 miles per day. 2004 Sea Gliders operate through a typhoon off east Asia 2005 Two Sea Gliders fly from Washington coast to Hawaii – 6 month mission 2005 Gliders launched from US Submarine

Ocean Glider Census – ~150 vehicles* Seaglider Spray Slocum No. in use 22 8 35 No. used in-house No. on order 15-20 12 50 * June 2006

Length 180cm, Diameter 30cm, Wingspan 100cm, Antenna 150cm   Slocum Seaglider Spray Dimensions Length 150cm Diameter 21.3cm Length 180cm, Diameter 30cm, Wingspan 100cm, Antenna 150cm Length 200cm, Diameter 20cm, Wingspan 110cm Speed ~40 cm/s ~25 cm/s ~25-30 cm/s Depth 4-200 meters 1000 meters 1500 meters Endurance 30 days 1-6 months 815 cycles to surface Power Alkaline Battery LiSoCl2 battery, 10MJ, 24/10V packs 52 Li CSC cells Weight 52 kg 51.8 kg Range 1,500 km 6,000 km 3500-4700 km

Slocum Seaglider Spray ~35 degrees 8-70 degrees (1:5 - 3:1 slope)   Slocum Seaglider Spray Data Transmission RF Modem, Iridium satellite, ARGOS, Telesonar modem Iridium satellite data telemetry, AMPS Cellular Range 1,500 km 6,000 km 3500-4700 km Navigation GPS, internal dead reckoning, altimeter GPS-based dead reckoning, GPS, Iridium satellite Glide Angle ~35 degrees 8-70 degrees (1:5 - 3:1 slope) 19-25 degrees

Slocum Gliders

Benefits ‘cheaper’ to operate when cf with shipborne observations Operations in all weather Designed for launch, monitor, recover or launch, forget, recover missions Telemetry rates via low earth orbit satellites are sufficiently inexpensive in both energy (~30 J/kilobyte) and cost (~$0.20/kilobyte) that the data return from a single glider (~120 kilobytes/day) is nearly that originally envisioned for the entire 3000-float Argo fleet using ARGOS while being a factor of ~200 less expensive.

Gliders are tools for appropriate Missions Need to balance quality of data spatial requirements temporal requirements costs to select best overall performance and value Glider mission can be changed at any time

Sensor Capabilities Real-time data available through the web Temperature Conductivity Salinity Depth Wavelength backscatter Fluorescence sensor Beam attenuation Passive Acoustics Real-time data available through the web Delayed mode calibrated, QC data available

Slocum Electric Glider Manufactured by Webb Research, USA

Slocum Electric Glider SENSORS CTD (conductivity, temperature, depth) - SeaBird Dissolved oxygen – Aanderaa Optode Fluorescence: Chlorophyll-a, CDOM (coloured dissolved organic matter), Phycoerythrin - Wetlabs Optical Backscatter:: turbidity through backscattered light at 470nm (blue), 530 nm (Green), 660nm (red).

Slocum Electric Glider

Glider Path: 22 days, 486 km, 2420 profiles

Depth-mean currents from glider

Glider cross-section: Sepia depression

Glider cross-section: Temperature

Glider cross-section: Temperature

Glider cross-section: Density

Glider cross-section: Backscatter

Glider cross-section: Temperature

Glider cross-section: Salinity

Glider cross-section: Temperature

Glider cross-section: Salinity

Glider cross-section: Density

Glider cross-section: Density

Investment plan Glider Purchase: 5 shallow (200m) and 5 deep (1000m) (30%) People: 3 people: glider preparation; Glider deployment and control; data provision (QC) Glider deployments: Data transmission costs, shipping Schedule: 2 shallow water gliders to be delivered in June 2007 2 deep water gliders to be delivered in November 2007 Others to come onboard in 2008.