Brief descriptionTwo 'Pulse' mooring platforms were deployed on the 5/10/2008, a 'Light' model and a 'Heavy' model mooring.
Instruments on the mooring collect the parameters listed in the lineage field, below.
Attached are the data files of those readings, as well as graphed results and some animations of the movement of the PULSE over time.
Moored instruments are deployed by the IMOS SOTS facility for time-series observations of physical, biological, and chemical properties, in the Sub-Antarctic Zone southwest of Tasmania , with twice-yearly servicing.
These time-series observations are crucial to resolving ecosystem processes that affect carbon cycling, ocean productivity and marine responses to climate variability and change, ocean acidification and other stresses.
This is one of only 29 high temporal resolution sites identified globally and 1 of 3 proposed for the Southern Ocean.
Pulse is a platform still under development. The design challenge for Pulse is not only to create a surface mooring that can endure the Southern Ocean but one that dampens the accelerations the surface float experiences enough so that the water sampler and biogeochemical sensors can function and survive long deployments.
LineageMaintenance and Update Frequency: daily
For this reason, and to meet shiptime constraints the mooring was deployed along the WOCE/CLIVAR SR3 line south of Tasmania in ~3500m of water. The surface buoy transmits its GPS position, which varies with wind and currents, as shown in Figure 1. The mooring (was?) recovered from Southern Surveyor in early April 2008, inspected for wear and damage, and prepared for a more completely instrumented deployment in spring 2008.
The main difference between Pulse Light and Pulse Heavy is that Pulse Heavy has an extra 450 m of wire and a water filled damper at bottom of top section. To make up for this Pulse Light has a taller bottom section. The water damper on Pulse Heavy adds inertial mass to the lower part of the top section, and because of the rubber elements higher up this mass helps to further isolate the instrument package from accelerations due to wave action on the surface float. The other benefit of having the the extra weight in the bottom of the top section is that it keeps the mooring more upright. As you can see by the figures below Pulse Light runs the risk of being completely stretched out due to current. If a wave slams surface float in when the mooring is stretched out completely the rubber elements could fail.
Pulse light's advantages are; less drag (as it has a smaller subsurface profile), and less stress on the rubber element due to not having that inertial mass.
Australia’s Integrated Marine Observing System (IMOS) is enabled by the National Collaborative Research Infrastructure Strategy (NCRIS). It is operated by a consortium of institutions as an unincorporated joint venture, with the University of Tasmania as Lead Agent.
University of Tasmania (UTAS)
Issued: 24 10 2008
Data time period: 05 10 2008
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DataFile:"TrackerPulseLight.csv" from LightPulse (format: csv) (TrackerPulseLight.csv)
DataFile:"TrackerPulseHeavy.csv" from HeavyPulse (format: csv) (TrackerPulseHeavy.csv)
DataFile:"StatisticsPulseHeavy.csv" -statistics of Modem for HeavyPulse (format:csv) (StatisticsPulseHeavy.csv)
DataFile:"StatisticsPulseLight.csv" -statistics of Modem for LightPulse (format: csv) (StatisticsPulseLight.csv)
DataFile:"StatusPulseHeavy.csv" -status of Modem for HeavyPulse (format: csv) (StatusPulseHeavy.csv)
DataFile:"StatusPulseLight.csv" -status of Modem for LightPulse (format: csv) (StatusPulseLight.csv)
- global : 10729bf5-fadb-49e5-a775-4d2546946fe1