Ice Tethered Profiler (ITP) Moorings WHOI Principle Investigators John Toole Rick Krishfield Andrey Proshutinsky WHOI Principle Investigators John Toole Rick Krishfield Andrey Proshutinsky

Goal: Document/understand interannual change through sustained observations of the Arctic ice pack, the overlying atmosphere, and the upper ocean water properties Ice-Based Observatories

System Specifications Capable of returning in real time, high accuracy daily (or semi daily) temperature and salinity profiles to 750m depth for 2 years. Deployable from light aircraft and/or helicopters through a conventional 10.5” (.26 m) ice-augured hole. Modestly priced, allowing them to be deployed in large numbers and be considered expendable. Capable of supporting plug-in modules for additional surface and/or subsurface instrumentation. Capable of returning in real time, high accuracy daily (or semi daily) temperature and salinity profiles to 750m depth for 2 years. Deployable from light aircraft and/or helicopters through a conventional 10.5” (.26 m) ice-augured hole. Modestly priced, allowing them to be deployed in large numbers and be considered expendable. Capable of supporting plug-in modules for additional surface and/or subsurface instrumentation.

Ice-Tethered Profiler Schematic Profiling Interval: 10m m or less Profiling range: 1,500,000 m Duration: years at one profile / day Temperature specification: -35° C Data telemetry: up to 50 kbytes / day Sensors: Seabird 41-CP CTD (same as ARGO floats) Telemetry: Seabird inductive link from profiler to surface unit; Iridium link to shore Power: lithium “DD” battery packs Size: Profiler fits through an 10.5” hole in the ice Profile speed:.2 meters/sec. (2 hours RT)

ITP Sensor Payload Options CTD DO – Dissolved Oxygen MAVS – Modular Acoustic Velocity Sensor Biohead – PAR Sensor, Fluorometer CTD DO – Dissolved Oxygen MAVS – Modular Acoustic Velocity Sensor Biohead – PAR Sensor, Fluorometer

Clamp on Inductive Instruments SAMI - PH SAMI (CO2) – CTD and PAR Microcat SAMI - PH SAMI (CO2) – CTD and PAR Microcat

ITP Deployment Operations

Finding an Ice Floe Multi year preferred 1.5 – 4.5 meters thick. Medium height ice ridges surrounding the site for protection Few cracks. If a suitable ice floe can’t be located, ITP system can be deployed in open water. Multi year preferred 1.5 – 4.5 meters thick. Medium height ice ridges surrounding the site for protection Few cracks. If a suitable ice floe can’t be located, ITP system can be deployed in open water.

Ice Thickness Survey

Set up on an ice floe helo assist

Staging Equipment

Set up deployment tripod

Drill ice hole

Ice hole

Mooring anchor

Start deployment with wire weight

Wire payout

ITP installed on mooring wire

Final Assembly of ITP electronics and mooring

Electro / Mechanical Inductive Hose Assembly

Success!

Can an ITP be Recovered?

Preferred Method - Smash it out!

Recovery of ITP 42

ITP 36 Deployed 08/29/2009 at N, E on NABOS cruise. Found in Iceland 2/2012

Data Examples

Double-diffusive Staircase Stratification Expanded views of the potential temperature profiles and potential temperature - salinity diagrams. Above the Atlantic Layer, temperature and salinity both decrease with height: a stratification subject to the diffusive layering form of double diffusion that is manifested by the staircase profile resolved by the ITP (left). Over plotted potential temperature-salinity curves at the level of the Atlantic Layer (right) clearly document intrusions that erode this warm salty water mass.

ITP1 Atlantic eddy profile

Expanded view of Atlantic water eddy

ITP3 engineering data

The End Thank You