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Project Title: |
Submesoscale Mixed-Layer Dynamics: Isolating the Sub- and Super-inertial |
Project Status: |
Submitted |
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Principal Investigator: |
James B. Girton, UW_APL |
Project Institution: |
UW_APL |
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Project ID: |
104724 |
Version #: |
2 |
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Date Submitted: |
2/11/2015 6:05:00 AM |
Created By: |
James B. Girton |
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Date Last Modified: |
8/19/2016 9:58:00 PM |
URI Serial #: |
None |
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Funding Agencies: |
NSF/OCE/PO - 1536314 - Funded |
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Summary of Field Work: |
The Submesoscale MIxed-Layer Experiment (SMILE) will be aimed at increasing our understanding of the role of lateral processes in mixed-layer dynamics through a series of ship surveys and Lagrangian array deployments targeting the upper-ocean’s adjustment to winter atmospheric forcing events. The SWIMS (shallow-water integrated mapping system) towed profiler will be used to make high-resolution surveys of upper-ocean temperature, salinity, oxygen, and fluorescence. EM-APEX (electromagnetic profiling explorer) profiling floats will measure temperature, salinity, temperature microstructure, and horizontal currents in clusters of up to 20 floats at a time. In addition, a drifting surface buoy will measure winds and atmospheric fluxes. The measurements will span 1–10 km scales, with floats making profiles every ½ hour to 100 m depth. We expect to make 5–7 deployments and recoveries, each 3–5 days in duration, over the course of a 28-day cruise in early 2017. The proposed location is the North Pacific Subtropical Front, approximately 800 km north of Hawaii. |
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Summary of Facility Requirements: |
We are requesting a global or ocean-class ship suitable for intensive over-the-side operations deploying and recovering EM-APEX profiling floats, cycling the SWIMS tow-body, and deploying and recovering the WHOI surface buoy. At a minimum, deck space for the surface flux buoy and for the SWIMS tow winch are required, in addition to the ability to deploy each while the other is on deck. Because both high-resolution and long-range ADCP currents are critical to the science, high-quality ADCP data quality is required, and the ability to install an additional ADCP (either 300 KHz Workhorse or 150 KHz broadband) in a spare transducer well is desired. Finally, EM-APEX recoveries are quicker and safer from a small boat than from the large vessel, so we are requesting a dedicated work boat (i.e., not needed for safety) for this purpose (to be used when weather permits). |
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Summary of other requirements and comments: |
Our initial request specified the R/V Thomas G. Thompson because of the availability of a multi-depth flow-through Temperature and Salinity measurement system installed by APL investigators Andy Jessup and Bill Asher. As the Thompson will be in dry dock during our field work, our second choice is the R/V Roger R. Revelle, which has a similar multi-depth CTD intake system. Third and fourth options include the R/V Oceanus and R/V Sally Ride (although the performance and suitability of the latter is not yet well known). Because of ADCP data quality concerns and the difficulty of over-the-side operations (respectively), we do not feel the R/V Sikuliak and R/V Kilo Moana to be viable alternatives for this project. |
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Type of Request: |
Primary Ship Use |
Request Status: |
Submitted |
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Request ID: |
1007547 |
Created By: |
James B. Girton |
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Date Last Modified: |
8/19/2016 9:58:00 PM |
Date Submitted: |
2/11/2015 6:05:00 AM |
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Year: |
2017
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Ship/Facility: |
Oceanus
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Optimum Start Date:
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3/1/2017 |
Dates to Avoid: |
March preferred (see below) |
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Earliest Start Date: |
1/1/2017 |
Multi-Ship Op: |
No |
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Latest Start Date: |
4/1/2017 |
Other Ship(s): |
Oceanus only |
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Operating Days Needed: |
Science Days |
Mob Days |
De-Mob Days |
Estimated Transit Days |
Total Days |
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24 |
3 |
1 |
4 |
32 |
Repeating Cruise?
(within same year) |
No |
Interval: |
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# of Cruises: |
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Description of Repeating cruise requirements: |
We are requesting 28 days at sea for this cruise. With an estimated transit of 2 days each way, this leaves 24 science days. |
Justification/Explanation for ship choice, dates,
conflicts, number of days & multi-ship operations: |
1) A 28 day cruise is requested to allow sufficient time to accomplish the scientific goals of observing multiple realizations of submesoscale mixed layer structures and adjustment to atmospheric forcing. Significant weather events are expected to occur every 3-5 days, and observations must be made over multiple inertial periods (1 day each). Thus we expect to be able to sample 5-8 events.
2) While a large Thompson/Revelle-class ship would be advantageous to allow switching among the multiple science activities planned: EM-APEX float deployment and recovery; drifting surface flux buoy deployment and recovery; and SWIMS tow-yo surveys, the ocean-class R/V Oceanus has adequate berthing and deck space to accommodate our needs in this experiment.
3) An additional advantage of the low-freeboard swell-following Oceanus is the easier access to small floating instruments (EM-APEX profiling floats) for recovery via a lifting line attached to a snap-hook on a pole. We anticipate conducting approximately 100 of these recoveries over the course of the experiment.
4) The experiment dates are motivated principally by the expected amplitude of atmospheric forcing and restratification processes in the Subtropical Front north of Hawaii. Late winter (Jan-April) is the best time to observe these processes. March is optimal because of the additional probability of calmer periods to allow array recovery and redeployment. |
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Short Description of Op Area
for use in schedules: |
N Pacific STF |
| Description of Op Area: |
The Subtropical Front is roughly 800 km north of Hawaii. The specific experiment location will be selected on the basis of satellite data in the region 147-159 W, 25-33 N immediately prior to the cruise, then refined on the basis of in-situ observations. We expect to operate within a roughly 200 km square region over the course of the cruise. |
| Op Area Size/Dia.: |
100 |
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Lat/Long |
Marsden Grid |
Navy Op Area |
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Beginning
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Ending
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Show Degrees Minutes |
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Foreign Clearance Required? |
No |
Coastal States:
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 Important Info on Foreign Research Clearances
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Are you or any member in your science party bringing in any science equipment items which are regulated for export by the International Traffic in Arms Regulations (ITAR) and/or the Export Administration Regulations (EAR)?
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No |
If yes, have you applied for the necessary permits through your export control office?
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No |
| Questions about ITAR/EAR regulations?
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Comments about foreign clearance requirements or
description of any other special permitting requirements
(e.g., MMPA, ESA, IHA, Marine Sanctuaries, etc.) |
none |
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Requested Start Port |
Intermediate Port(s) |
Requested End Port |
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Honolulu, HI, USA |
None, , None, |
Honolulu, HI, USA |
Explanation/justification for requested
ports and dates of intermediate stops
or to list additional port stops |
Honolulu is the closest, most capable port |
Important Info on Working in Foreign Ports
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Chief Scientist: |
James B. Girton, UW_APL |
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# in Science Party |
13 |
# of different science teams |
1 |
# Marine Technicians to be
provided by ship operator:
(include in science party total)
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1 |
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Explanation of Science Party Requirements and Technician Requirements |
We expect to conduct round-the-clock EM-APEX and SWIMS operations, working in shifts. SWIMS launch and recovery requires approximately 6 people, as does launch and recovery of the drifting surface buoy. The 12-person science party will be made up of personnel from APL-UW, WHOI, and NWRA. Assistance from a shipboard technician will be needed for maintenance and quality control of shipboard instrumentation (ADCP, CTD, Thermosalinograph), as well as for launch and recovery of profiling floats. EM-APEX operations will use a small crane or A-frame block and the science party's quick-release and recovery hooks. |
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 Dynamic Positioning |  ADCP | Multibeam | Seismic |
| Dredging/Coring/Large Dia. Trawl Wire | Stern A-frame | Fiber Optic (.681) | 0.680 Coax Wire |
| SCUBA Diving | Radioisotope use - briefly describe | NO Radioisotope use/Natural level work | Other Operator Provided Inst. - Describe |
| 0 PI-Provided Vans - briefly describe | MOCNESS | | |
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Explain Instrumentation or Capability
requirements that could affect choice
of ship in scheduling. |
Because EM-APEX recoveries are quicker and safer from a small boat than from the large vessel, we request the use of a work boat that can be dedicated for this purpose (i.e., not required standing by for safety). The small boat will be used for EM-APEX recoveries whenever weather and sea state permit.
We also are likely to want to install our own 150 KHz broadband ADCP in a spare transducer well for higher resolution currents in the upper water column than available from the 75 KHz ship system (and longer range than the 300 KHz). If necessary, this could be swapped for the 300.
Finally, we anticipate a small number of CTD casts (roughly 1 per day) with a rosette water sampler for calibration of the SWIMS sensors.
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Explain Major Ancillary Facilities
Requirements and list description
and provider for "other" systems. |
SWIMS winch will need to be installed |
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