PRIMER / Coastal Mixing & Optics (ONR-sponsored)
R/V Oceanus--Voyage #281
submitted by Murray Levine, Chief Scientist

I. Deployed moorings at the Central site -- 3 moorings were set along a 500 m line in a north-south direction (CENTRAL GUARD, OSU MAIN, AUXILLARY); 1 mooring (OSU MET) is 260 m to the west of AUXILLARY. (Figure of layout in ftp site.)

A. OSU MAIN-- 40 ° 29.50' N; 70 ° 30.46'W -- no scope

1. Taut subsurface mooring with tethered surface marker buoy (radar reflector & flashing light)


2. Instrumentation: Temperature recorders (15), T-C Seacats (5), Doppler profiler (RDI ADCP), Rotor current meters (2), Dickey's BIOPS (3), acoustic release

B. OSU MET-- 40 ° 29.37'N; 70 ° 30.64'W --max scope 70 m radius


1. Surface buoy with meteorological mast, radar reflector & flashing light
   
2. Instrumentation: Temperature recorders (5); Doppler profiler (Sontek ADP); Air temp, barometer, wind velocity, humidity, insolation, acoustic release

C. AUXILLARY-- 40 ° 29.38'N; 70 ° 30.46'W -- WHOI buoy --max scope 70 m radius


1. Surface buoy with radar reflector and flashing light
   
2. Instrumentation: Temperature recorders (5)

D. CENTRAL GUARD-- 40 ° 29.65'N; 70 ° 30.46'W --WHOI buoy-- max scope 70 m radius


1. Surface buoy with radar reflector and flashing light
   
2. Instrumentation: none

II. Vertical profiles with CTD (SBE 25) with transmissometer and fluorometer

A. North-south transect along 70 ° 30'W with sampling to 80% of depth or 200 m (A preliminary listing of these data will appear soon in the ftp site.)

Station	Latitude, N	Water depth, m
#1	40 ° 54'	51
#2	40 ° 49'	52
#3	40 ° 44'	54
#4	40 ° 39'	59
#5	40 ° 34'	63
#6	40 ° 29'	70
#7	40 ° 24'	80
#8	40 ° 19'	95
#9	40 ° 14'	115
#10	40 ° 09'	121
#11	40 ° 04'	180
#12	39 ° 59'	625
#13	39 ° 54'	1050

B. Time series at Central Site --profiles to 60 m

• Start time: 1400 UT 7/11/96
• Duration: 16 hours
• Sampling: 1 cast every 15 minutes; additional casts at 5 and 10 minutes after the hour

III. Bathymetric survey--using lab PDR--around central site. About 10 north- south lines 1 km apart between shipping lanes. No surprises--flat, gentle slope.

IV. Auxillary data

A. Ship system-- 1 minute averages-- GPS (P-code) position, IMET (wind velocity, air temperature, barometric pressure, humidity, short wave radiation, precipitation), surface temperature and salinity, ship heading and speed

B. ADCP --(quality uncertain)


1. 150 kHz --Narrowband
2. 300 kHz --Broadband

Comments:

1. There is much lobster gear in the water. Possible configuration, according to the Captain:

• At one end-- a weighted nylon line is attached to a small rubber float and a hard float with a pole (6') with a radar reflector ("high flyer" )
• At the other end-- a small rubber float (with or without "high flyer")
• In the middle-- maybe 50 lobster pots strung together with 3/4" poly line; separation between pots may be 100 feet; a lobster pot is about 3'x4'x5'

  These strings of pots are typically deployed along isobaths and often along Loran lines. Pots are recovered and redeployed at least weekly(?); hence positions will change. We did snag a line and dragged a float under water while towing a mooring into position for launch; just before attempting to retrieve mooring, the line came free. (An example copied from the radar screen near the central site will be located soon in the ftp site). Note that radar returns from moorings could not be distinguished from the "high flyers".

2. Deployment operations went smoothly--OSU MAIN and OSU MET were deployed during daylight on 9 July; AUXILLARY and CENTRAL GUARD were set on 10 July. Weather was great--little wind, swell and sea; some rain and heavy fog on 9 July; clear on 10 July. Hurricane Bertha stayed far south. CTD operations took place between mooring deloyments at night and continuously from midday on 10 July until the morning of 12 July. We returned to WHOI Friday afternoon 12 July, one day early.

3. Description of water column (caution: written by scientists at sea)

• Central site
  Upper layer--surface to 5 - 10 meters-- T=18.5 to 19.5 deg C; S= 32 psu
  Pycnocline--10 to 20 m-- Buoyancy frequency-- 15 to 25 cph
  Below 25 m -- Buoyancy frequency-- 4 to 5 cph
• Between stations #6 and #11 pycnocline depth varies in time/space between 10 and 20 m.

• Front near station #12 over slope.

4. Scientific party

• OSU -- Murray Levine, Timothy Boyd, Jay Simpkins, Walt Waldorf, Kieran O'Driscoll, Jose de Bettencourt
  
• UCSB -- Tommy Dickey, Derek Manov, David Sigurdson
  
• Merchant Marine Academy -- David Lytkowski
• SSSG Tech -- Laura Goepfert

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Last Modified: 1 October, 1996