Woods Hole Oceanographic Institution

Cruise Planning Synopsis


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KN200-02

Ship

R/V Knorr

Cruise Party

Dave Hebert: Chief Scientist, Principal Investigator
GSO, University of Rhode Island 215 South Ferry Road Narragansett, RI USA 02882
+1 902 426 1216
hebert@gso.uri.edu

Departure: Feb 27, 2011

Halifax

Arrival: Apr 4, 2011

Halifax

Operations Area

northeast of Flemish Cap. off Newfoundland, Canada
Lat/Lon: 50° 0.0′ N / 43° 0.0′ W
Depth Range: 100 / 2000
Will the vessel be operating within 200 NM of a foreign country? Canada
Are visas or special travel documents required? no

Science Objectives

The cruise track shows the area (300 km x 300 km) of the high-resolution (HR) eddy survey.  The actual location of the stations will be determine just before the cruise based on satellite altimeter data and on the transit to the first CTD station.   The survey would consist of north/south transects separated by 60 km along which the velocity field, using the shipboard acoustic Doppler current profiler (ADCP) will be measured continuously to about 700 m depth.  Every 50 km, a  CTD cast to 1000 m will be done.  Between CTD stations, an underway CTD system, operating in a tow-yo mode, will provide a CTD profile to 250 m at 10 kts every 10 minutes (3 km).   XBTs will be used as backup to provide temperature profiles to 800 m halfway between normal CTD casts.  These surveys will take 5.5 days each to complete.

Between the two HR surveys planned, a larger scale survey to map out the surrounding eddy field and fronts, the NAC from the south and the waters leaving the eddy formation region to the east. This large scale survey will allow us to detect whether previous eddies are located in the region. If so, we can determine their structure and whether it is consistent with our hypothesis of sinking or interacting with the continental shelf and producing cyclonic eddies.  CTD casts will be undertaken every degree of latitude (~110 km) along the transects which are separated by approximately 80 km.  This survey will take about 12 days to complete.  Underway CTD casts and XBTs will be done between the CTD stations.

Time permitting, we will occupy some of the CTD stations on a repeated Canadian hydrographic line from St. John’s tp Flemish Cap.  Also, as a favour to the Canadians (eg. NRCan), the multibeam will collected and provided to them.   Someone from NRCan will discuss settings, etc. when the ship is in Halifax.

In addition to the above work, ARGO floats and surface drifters will be deployed through the survey region.

Science Activities

The Gulf Stream travels along the eastern seaboard of the United States and Canada 

bringing warm water northwards. South of Newfoundland, the Gulf Stream separates

into two currents, one that moves around the Grand Banks and travels northward

until approximately 500N where it heads eastward across the North Atlantic. This

current is known as the North Atlantic Current (NAC).  In this region where the NAC

turns eastward, eddies are generated on a regular basis.  The mechanism for their

formation and their evolution is unknown. This National Science Foundation project

is to investigate these processes.

Our hypothetical conceptual dynamical model of the formation, growth and

separation of the NWC eddy would consist of the following processes:

(1) Gradual accumulation of kinetic energy in an anticyclonic loop east of Fleming

      Cap related to the momentum imbalance in the NAC turning from northeast to

      northwest along the continental slope and splitting into two branches.

(2) Shedding a warm-ÂÂÂÂÂA?core eddy after the recirculation loop increases to a size when

      the beta-effect is able to provide substantial self-propagation.

(3) Either substantial heat loss from the ocean to the atmosphere resulting in the 

      sinking the eddy core followed by a capping of the eddy or the eddy interacts 

      with the shallow shelf and continental slope resulting in submesoscale cyclonic

      eddies generation and enhanced decay of the anticyclonic eddy.

Satellite-based observations suggest that the life cycle for this process is 

approximately 2.5 months and the eddies, while present year round, are dominate in

the spring.

To address whether this model is realistic, we plan two ~30 day expeditions 

separated by approximately 1 month.  During each cruise, two high-ÂÂÂÂÂA?resolution

hydrographic surveys of the eddy region will conducted.  Between the two surveys,

a larger scale, coarse resolution survey of the region will be undertaken

 

Additional Info

Pre-cruise Planning Meeting: Visit WHOI
Meeting Notes: Will travel to WHOI week of Jan 17th.

Stations:

  Station 1
  Distance: 1050
  Days: 1 hr
  Latitude: 52° 0.0’ N
  Longitude: 40° 50.0’ W

Supporting documentation:

»Knorr_cruise_track_expanded.pdf
»Knorr_cruise_track.pdf

Funding

Funding Agency: NSF
Grant or contract number: OCE 1027573

Scientific Instrumentation for R/V Knorr

Shipboard Equipment

Bathymetry System 12 kHz
Sippican XBT System (Mark 21)
Bathymetry System 3.5 kHz
Multibeam
Science Underway Seawater System
ADCP 75 kHz

CTD/Water Sampling

911+ Rosette 24-position, 10-liter bottle Rosette with dual T/C sensors
SBE43 oxygen sensor
Wet Labs ECO-AFL fluorometer
Wet Labs C*Star transmissometer (660nm wavelength)

Critical CTD Sensors

MET Sensors

Barometric Pressure
Wind speed and direction
Air temperature
Relative Humidity
Precipitation
Short Wave Solar Radiation
Storage Notes:

Navigation

Will you be using Long Base Line (LBL) navigation? no
How many nets? 0
How many tansponders? 0
Will you be using Doppler/GPS navigation?yes
Navigation Notes:

Winches

CTD Winch with .322" Electro-mechanical wire
Winch Notes:
Wire Notes:

Standard Oceanographic Cables

Slip ring required? no Number of conductors: 
Non-standard wire required? no Type: 
Traction winch required? no Describe: 

Specialized Deck Equipment

Mooring Deployment/Recovery Equipment Required: no Type: 
Cruise Specific Science Winch Required: yes Type: 110V power for uCTD (see below
Nets Required: no Type: 

Over the Side Equipment

Will you be bringing any equipment (winches, blocks, etc.) that lowers instruments over the side? yes
Details:
Underway CTD (uCTD) system (Ocean Sciences)
This will deploy off stern / fantail.  Science will bring all parts and mounts. 

Special Requirements

Elecrical Power: yes Identify: for UCTD - 480V
Equipment Handling: no Identify: 
Inter/intraship Communications: no Identify: 
Science Stowage: no Identify: 
Water: no Identify: 

Additional Cruise Items/Activities

Explosive Devices:no
Portable Air Compressors:no
Flammable Gases:no
Small Boat Operations:no
SCUBA Diving Operations:no

Hazardous Material

Will hazardous material be utilized?no
Describe deployment method and quantity:

Radioactive Material

Radioiosotopes:no

Additional Information

Is night time work anticipated on this cruise?yes
Specialized tech support (Seabeam, coring, other):
Seabeam used for tech training, etc.
Other required equipment and special needs:
Deck mounted XBT launcher

Checklist & Notes

Checklist

U.S. Customs Form: yes
Diplomatic Clearance: yes
Date Submitted: Nov 27, 2010
Date Approved:
Agent Information:

Master R/V KNORR
Attn: Scientist's Name / KN200-2
IN TRANSIT
c/o Mathers Logistics Ltd
1525 Birmingham Street
Halifax, Nova Scotia
B3J 2J6, Canada

Phone: (902) 429-5680 (24 hrs)
Fax: (902) 429-5221
Telex: 019-21771 
Email:operations@matherslogistics.com

Contacts:  Gus Webb 
                Cory Tanner

Large shipments should be sent to the following address.   Please submit all pre-alert documents to the agent prior to the shipment's arrival.

Master, R/V Knorr
Attn:  Scientist's Name
c/o Mathers Freight Management
165 Burbridge Avenue
Dartmouth, Nova Scotia
Canada, B3B 0G6

Phone: (902) 468-6544

Note: Agent and WHOI contacts should be copied on all communications. It is requested that shipment information of any equipment be communicated to the Agent and to WHOI contacts.
Countries:
Canada
Notes:
4455's for gear loaded at WHOI Jan 20, 2011.
Isotope Use Approval: no
Isotope Notes:
SCUBA Diving: no

Checklist

SSSG Tech:
Some items loaded on Knorr Jan 20 2011. 
Rest loaded in Halifax.