CRUISE REPORT PRIVATE  

HUDSON 98023

LABRADOR SEA

WOCE LINE AR7W

22 June - 9 July, 1998


A.  CRUISE NARRATIVE
1.  Highlights

a.   WOCE Designation:		WOCE Line AR7W
					Atlantic Circulation Experiment

b.   Expedition Designation:	Hudson 98023

c.   Chief Scientist:		E. Peter Jones
					Ocean Sciences Division
					Department of Fisheries and Oceans
					Bedford Institute of Oceanography
					PO Box 1006
					Dartmouth, NS, Canada B2Y 2A4

					FAX 		902 426 7827
					Internet	jonesp@mar.dfo-mpo.gc.ca
		
d.   Ship:				CCGS Hudson

e.   Ports of Call:		June 22	BIO, Dartmouth, NS, Canada
					July 9	BIO, Dartmouth, NS, Canada


f.   Cruise Dates:		June 22 to July 9, 1998
		

2.   Cruise Summary Information

a.   Cruise Track 

A cruise track is shown in Figure 1.  Ship position at 0000Z on each day of the 
cruise is indicated with a date label.  


 

Figure 1.  Cruise track for 18HU98023/1.  The date labels indicate the ships 
position at 0000Z.

b.   Total Number of Stations Occupied

The CTD and ROS station positions are shown in Figure 2 (Scotian Shelf) and 
Figure 3 (WOCE Line AR7W).  Some station numbers are indicated for clarity.  The 
WHP stations are all contained in the box defined by 50-62_N and 43-60_W (Figure 
3).

Table 1 lists the science operations for 98023.

Cast	Number of	Detailed Division				Operation 
Type	Operations							Numbers

ROS	41		22 AR7W Sites				see Table 2
			7 Halifax Line Sites			see Table 3
			5 Biology Casts				22, 42, 55, 87, 103
			1 Chemistry Equipment Test		20
			1 Oxygen sampling Test			24
			1 Seacat Calibration			69
			1 13C cast					100
			1 no samples due to mistrips		82
			1 aborted					15
			1 Basin test				1
			
CTD	1		1 test of replacement CTD probe	83
			
FLT	2		51, 58
			
MOR	11		7 operations to recover 6 moorings	38, 45, 52, 63(98), 67, 79
			2 deployments				40, 71
			2 release tests				39, 70
			
BIO	49		41 shallow net tows	
			2 deep net tows				47, 76
			6 light meter 				43, 56, 68, 88, 101, 104

Table 1.  Science operations conducted on 18HU98023/1.


AR7W			98023 ROS 
Site Number		Operation Number

1			26
2			28
3			30
4			32
5			33
6			35
7			37
8			44
9			50
10			48
11			57
12			61
13			62
14			66
15			74
16			77
17			78
18			84
19			89
20			92
21			95
22			97

Table 2.  AR7W sites and rosette operation numbers for 18HU98023/1.


Halifax	98023 ROS 
Line Number	Operation Number
1	3
2	5
3	8
4	10
5	12
6	16
7	19

Table 3.  Halifax Line sites and rosette operation numbers for 18HU98023/1.




 


Figure 2.  CTD/ROS station positions on the Scotian Shelf for Hudson 
18HU98023/1.


Along AR7W, the stations were full depth WHP small volume rosette casts with up 
to 24 rosette bottles.  Depending on the station, water samples were analyzed 
for CFC's, carbon tetrachloride, methyl chloroform, total carbonate, alkalinity, 
oxygen, salinity, nutrients, oxygen isotopes, helium and tritium.


c.   Floats and Drifters deployed

The deployment sites for PALACE floats are shown in Figure 4.  Two profiling 
ALACE floats were launched at stations 51 and 58.



 

Figure 3.  CTD/ROS station positions on the WOCE Line AR7W for Hudson 
18HU98023/1.


 


Figure 4.  PALACE float deployment positions (_) and mooring positions (_) 
during Hudson 18HU98023/1.  The float serial numbers and BIO Mooring numbers are 
also indicated.


d.   Moorings deployed or recovered
				
A total of 11 mooring related operations, consisting of deployments, recoveries 
and release tests were conducted at various sites as shown in Figure 4.  The 
following summarizes the mooring operations and provides a legend for Figure 4.

Deployments:

	   1	M1276 standard mooring consisting of one current meter positioned 
20m off bottom was set across the Labrador Slope along AR7W (12 month 
deployment) along the 1000m isobath

	   1	M1275 multi-instrument mooring was set near OWS Bravo on AR7W 
replacing the mooring M1255 set in 1997 (WOCE Expocode 18HU97009/1).  The 
deployed mooring consisted of 7 Seacat temperature/conductivity recorders, 6 
Aanderaa current meters, and 3 SBE39 (two with temperature, and one with 
temperature and pressure)

Recoveries:

	   1	SSN (Sound Source North) mooring for RAFOS floats was recovered (not 
shown in Figure 4)

	   1	M1255 was partially recovered.  Retrieved 2 Seacats and 3 Aanderaa 
current meters.  Lost were 3 Aanderaa current meters, 4 Seacats, 1 WOTAN and 3 
WADAR (TSKA water data recorders).  

	   1	M1256 recovered consisting of 1 current meter moored at 20m off 
bottom along the 1000m isobath (same position as M1276 in Figure 4).

	   1	M1244 recovered all instruments, which consisted of 5 Aanderaa 
current meters.  

	   1	M1245 attempted to contact both releases.  Neither release 
responded.  This mooring consisted of 5 Aanderaa current meters.

	   1	M1246 was released at station 63.  The release indicated that it had 
released, but it did not move off the bottom.  We assume that the mooring line 
is tangled in the anchor.  The main float and top current meter had been 
previously found in Iceland.  Hudson returned to the mooring site at station 98 
and commenced dragging operations.  This was successful, with the retrieval of 2 
acoustic releases, 3 current meters and one current meter vane.




3.   List of Principal Investigators

Name					Affiliation 	Responsibility

Allyn Clarke			BIO			scientist
clarkea@mar.dfo-mpo.gc.ca				overall co-ordination
								
Glenn Cota				Old Dominion 	Bio-Optical properties of the
cota@ccpo.odu.edu			University		upper ocean 
								
Bob Gershey				BDR Research	alkalinity, carbonate, CFC's
rgershey@fox.nstn.ns.ca					

Glen Harrison			BIO, 			Co-ordinator biological program
harrisong@ mar.dfo-mpo.gc.ca				nitrate and ammonium utilization
								by phytoplankton
								
Erica Head				BIO			macrozooplankton distribution,
heade@ mar.dfo-mpo.gc.ca				abundance and metabolism

Robert Houghton			LDEO			oxygen isotopes
houghton@ldeo.columbia.edu	

Paul Kepkay				BIO			dissolved organic carbon,
kepkayp@ mar.dfo-mpo.gc.ca				colloid chemistry and plankton
								respiration

Peter Jones				BIO			senior scientist
jonesp@ mar.dfo-mpo.gc.ca				alkalinity, carbonate, CFC's

John Lazier				BIO			CTD data, moored instrument data
lazierj@ mar.dfo-mpo.gc.ca	

Bill Li				BIO			pico-plankton distribution and 
lib@ mar.dfo-mpo.gc.ca					abundance

Robert Pickart			WHOI			lowered ADCP
pickart@rsp.whoi.edu	

Peter Rhines			UW			moored instrument data
rhines@killer.ocean.washington.edu	

Fritz Schott			IFM Kiel		PALACE floats
fschott@ifm.uni-kie.de	

Table 4.  List of Principal Investigators.  See Section 7 for addresses.

4.   Scientific Program and Methods

4.1   Physical - Chemical Program

a. Narrative

This expedition was conducting  physical and chemical oceanographic operations 
in support of two ongoing scientific initiatives.

The first initiative is the Atlantic Circulation Experiment of the World Ocean 
Circulation Experiment (WOCE). One element of this experiment seeks to map the 
hydrographic and tracer fields of the subpolar gyre of the North Atlantic to 
provide a measure of the winter cooling and water mass transformations over the 
entire region. Hudson 98023 was planned to map the Labrador Sea part of the sub-
polar gyre as well as to deploy current meter moorings and profiling ALACE 
floats, which will measure the changes in the hydrographic structure and the 
gyre circulation over the coming 12 months. This cruise is the continuation of 
the program to occupy the WOCE line AR7W annually and seasonally to study deep 
convection and variability in the Labrador Sea in the context of thermohaline 
circulation in this key region of the North Atlantic subpolar gyre.

The second initiative is the Labrador Sea project of the Canadian Joint Global 
Fluxes Study (JGOFS). This project seeks to measure the vertical fluxes of 
carbon from the atmosphere to the deep ocean and its sediments. The biological 
program on Hudson 98023 was designed to characterize late spring-summer 
biological processes in the Labrador Sea and its shelf regions. The program also 
includes collecting light measurements, which will be used to develop the 
regional algorithms that will allow primary productivity estimates to be made 
using data from Ocean Color satellite sensors such as Sea WIFS. The physical 
oceanographic program is observing total carbonate, alkalinity and CFCs over the 
entire water column in support of these JGOFS objectives.

During this cruise, an ADCP was added to the CTD/rosette package to provide a 
estimate of the full depth velocity profile at each CTD station.  This data will 
be useful for the detection and definition of various subsurface currents such 
as the deep western boundary undercurrents.

A total of 2 PALACE floats were deployed throughout the Labrador Sea.  These 
instruments should provide weekly information on the changes in the heat and 
salt distributions of the upper 1500 m of the water column throughout the 
cooling season.


4.2   Biological Program

a.	Narrative

The biological program studied the distribution and physiology of the major 
plankton groups; bacterioplankton, phytoplankton and zooplankton. The spectral 
distribution of light in the water column was also examined. 

b.	Phytoplankton Program

All stations on the Halifax line and some of the stations on the Labrador Sea 
line were sampled every 10 m to 100 m for chlorophyll, nutrients, and CO2 (Table 
5).  Integrated collections through the upper 50m were also taken for 
phytoplankton and microzooplankton.  

Station	Operation	Lat.	Long.
HL 1		3		44.40	63.47
HL 2		5		44.27	63.32
HL 3		8		43.88	62.88
HL 4		10		43.48	62.45
HL 5		12		43.18	62.10
HL 6		16		42.85	61.68
HL 7		19		42.53	61.40
SABLE	2	2		44.83	60.27
GULF		24		49.85	58.72
Site 1	26		53.68	55.55
Site 2	28		53.80	55.44
Site 3	30		53.99	55.25
Site 4	32		54.22	55.02
Site 6	35		54.76	54.49
Site 7	37		54.95	54.29
Site 8	42		55.11	54.14
Site 11	55		55.61	53.63
Site 15	69		56.95	52.24
Site 19	87		58.64	50.42

Table 5.  Phytoplankton sampling.


When it was possible to obtain larger volumes of water during the daylight hours 
Photosynthesis-Irradiance experiments (Table 6) were conducted on populations 
from two depths.

Station		Operation	Lat.	Long.
NE SABLE IS.	22		44.83	60.27
GULF			24		49.85	58.72
Site 8		42		55.11	54.14
Site 11		55		55.61	53.63
Site 15		69		56.95	52.24
Site 19		87		58.64	50.42

Table 6. Photosynthesis-Irradiance experiments.


c.	Zooplankton Sampling							L. Harris

The zooplankton sampling is part of an ongoing program, the aim of which is to 
investigate the distribution, abundance and life history of the major 
zooplankton groups found in the Labrador Sea and its associated shelf systems. 
Particular emphasis is placed on the copepod species of the Calanus genus , who 
dominate the zooplankton in this region.

Vertical net tows were taken at 28 stations ( 8 on or near the Scotian Shelf, 1 
in the Gulf and 19 from the Labrador Shelf/Labrador Sea) using a 3/4 m 200 _m 
mesh ring net. At all stations, tows were made from 100 m to the surface. 
Additional deep tows (2500 m to the surface) were taken at two of the stations 
in the Labrador Sea . Samples will be analyzed for species composition, copepod 
stage structure and biomass.


d.	Measurements Of Copepod Metabolic Rates

Respiration rates (CO2 production) of the copepod communities were determined at 
6 stations in the Labrador Sea.


e.	Microbiological Samples
	Bob Whalen, Michael Hanson and Robin Anderson

Microbiological samples were collected and experiments were conducted at 
stations on the AR7W line.  Depth profiles were collected at 9 sites.  Samples 
for bacteria enumeration were collected from 11 depths (1, 10, 20, 30,...100m) 
for a total of 99 samples.

Microzooplankton dilution grazing experiments were conducted at sites 2, 8, 14A, 
and 19.Samples for Total Chl A, 5 _m  Chl A, bacteria, and protozoa were 
collected prior to the experiment.  Samples taken at time points include total 
Chl A, bacteria, and picoplankton.  The total  number of grazing experiments was 
4.

A total of 6 experiments on temperature dependent and nutrient dependent 
bacteria growth were carried out at the sites of the grazing experiments.


f.	Dissolved Organic Carbon (DOC) and Microbial Community Respiration	
	Jay Bugden and Paul Kepkay

Samples for DOC profiles, size fractionation of DOC (ultrafiltration) and 
microbial community respiration were collected at 15 stations on the AR7W line 
(see Table 7).  Ultrafiltration and rates of respiration of seawater samples 
were carried out at the time of collection (the ultrafiltration samples were 
frozen for later laboratory analysis), while samples for the DOC profiles were 
filtered and frozen for later analysis.

Station			Respiration	Ultrafiltration	DOC Profile
Site 1 (AR7W Line)	X		X			X
Site 4			X		X			X
Site 6								X
Site 7								X
Site 8			X		X	
Site 9								X
Site 11			X		X	
Site 12								X
Site 14								X
Site 16								X
Site 18								X
Site 19			X		X	
Site 19 Deep (2000m)	X		X	
Site 20								X
Site 21								X
M1255 Mooring Site	X		X	

   
Table 7.  DOC sample collection.

g.        Satlantic Profiling Multichannel Radiometer	Dave Ruble

Profiles of spectral light characteristics were taken at 6 stations from the 
surface to below 0.0001% surface PAR (in most cases >70m).  Spectral profiles 
will be processed to calculate values of water-leaving radiance at 13 
wavelengths.  Two and three channel band ratios will be correlated with values 
of near-surface chlorophyll to generate regional algorithms for remote sensing 
of biomass and production in the Labrador Sea.  

Initial problems with the Profiler occurred due to the wrong configuration of a 
new Power / Telemetry circuit board installed by Satlantic just prior to 
leaving.  Satlantic was contacted and they faxed detailed instructions for 
disassembling the Profiler and rewiring of the Power / Telemetry circuit board.  
The first attempt did not work, however the second set of instructions did fix 
the problem and the Profiler has functioned normally for the remainder of the 
cruise.

 h.        Bacterial Abundance and Activity	Paul Dickie and Bill Li

Seawater from the CTD was sampled for phytoplankton and microzooplankton 
(identification and enumeration) by combining 50 ml aliquots of water from each 
depth between the surface and 90 m and preserving with acid Lugol.  Samples from 
individual depths were taken from the same water to count bacteria and 
autofluorescent cells by flow-cytometry.  Stations (operation numbers) sampled: 
3, 5, 8, 10, 12, 16, 19, 22, 24, 26, 28, 30, 32, 35, 37, 42, 55, 69, 87, 100, 
103. 

At several stations, experiments were performed on the marine micro-
heterotrophic populations using tritiated thymidine and leucine to check 
reproductive and biomass growth rates vs. depth over the photic zone.  Stations 
sampled were: 24, 26, 42, 55, 69, 87 and 103.  One dilution experiment (stn. 87) 
and one enrichment experiment (stn.98) were conducted to test effects of  
predation and thymidine / leucine enrichment on the growth experiments.


5.   Major Problems and Goals Not Achieved

5.1   Mooring Operations

There were major problems with three moorings.  One, M1245, could not be located 
and is presumed lost.  One, M1246, was known to have lost its top buoyancy.  We 
located it but it failed to come up when the release command was sent.  It was 
recovered subsequently by dragging and had lost only one of its current meters.  
The third, M1255, was recovered with about half of its instrumentation missing.  
Both M1246 and 1255 lost buoyancy very soon after they had been moored, and will 
thus provide almost no useful data.  Why these three moorings failed will have 
to await further analysis, but a reevaluation of mooring design is essential and 
urgent.

5.2   Sites 23 to 28

Unfortunately, sites 23 to 28 on the Greenland side of the Labrador Sea were not 
occupied.  A medical emergency required the discontinuation of the line after 
Site 22.  Hudson attempted a port call at Julianehaab, Greenland, but due to 
heavy ice was routed across the Labrador Sea to St. Anthony, Newfoundland.

5.3   Profiling Radiometer

The Satlantic SeaWIFS Multichannel Profiling Radiometer was inoperative for 
about half of the cruise.  It had been overhauled just before being put on board 
and checked out by the manufacturer prior to sailing.  Nevertheless, an 
essential internal connection had not been made.  After several contacts with 
the manufacturer, the ship's technician was able to get the instrument 
operative.  This part of the biological program was, however, strongly impacted 


6.   Other Incidents of Note

none


7.   List of Cruise Participants

Name			Responsibility					Affiliation

Jeff Anning		Underway Sampling, photosynthesis, pump	BIO
Rick Boyce		Technician, Moorings				BIO
Jay Bugden		DOC Levels, respiration rates			J&S Envirotech, 
										Dartmouth
Pierre Clement	Nutrients						BIO
Paul Dickie		Bacterial abundance and activity		BIO
Jennifer Dixon	Oxygens						BDR
Mike Fougerousse	Bio-optical						ODU
Bob Gershey 	Scientist, CO2, CFC's, Alkalinity		BDR
Jean Hanley		Helium, Tritum					LDEO
Michael Hanson	bacteria growth					MUN			
Les Harris		Zooplankton, Net Tows				BIO
Albert Hartling	Winch Room, moorings				BIO
Ross Hendry		Scientist, watchkeeper				BIO
Mike Hingston	Technician, CO2, CFC's, Alkalinity		BDR
Anthony Isenor	Data Manager 					BIO
Peter Jones		Senior Scientist					BIO
John Lazier		Assistant Scientist				BIO
Dave Ruble		Bio-optical						ODU
Murray Scotney	Moorings, instrumentation			BIO
Leif Thomas		Watchkeeper						UW
Bob Whalen		Microzooplankton					NWAFC
Frank Zemlyak	Technician, CO2, CFC's, Alkalinity		BIO


BIO			Bedford Institute of Oceanography
			PO Box 1006
			Dartmouth, NS, B2Y 2A4


BDR			BDR Research Ltd.
			Box 652, Station 'M'
			Halifax, N.S., 	B3J 2T3


IFM-Kiel		Institut für Meereskunde an der Universität Kiel
			Düsternbrooker Weg 20
			D-24105 Kiel, Germany


LDEO			Lamont -Doherty Geological Observatory
			Columbia University
			Palisades, New York 10964


MUN			Memorial University of Newfoundland


NWAFC			Northwest Atlantic Fisheries Centre
			Newfoundland, Canada


ODU			CCPO
			Old Dominion University
			Norfolk, VA 23529
			USA


UW			University of Washington
			Seattle, WA 98195


WHOI			Woods Hole Oceanographic Institution
			Woods Hole, MA 02543

	B.  UNDERWAY MEASUREMENTS

1.   Navigation and Bathymetry	Anthony W. Isenor

The navigation system onboard CCGS Hudson consists of a Trimble Navigation 
Loran-GPS 10X decoder and AGCNAV.  The decoder receives the satellite fixes and 
decodes the signals to obtain latitude, longitude and time.  The decoder signals 
are about 1 Hz.  The navigation data were logged at one minute intervals on a 
PC.  This PC was running the AGCNAV software package, a PC based display, and 
way-point setting software package developed at the Atlantic Geoscience Centre 
at BIO.  This software graphically displays ship position, way-points, course, 
speed, etc. to the various science working areas.

The echo sounder system used for collecting bathymetric data consisted of a 
Raytheon Line Scan Recorder, Model LSR 1811-2 (serial number A117) connected to 
a hull mounted 12kHz transducer.  The transducer beam width is 15 degrees.  The 
sweep rate of the record was adjusted throughout the course of data collection 
to aid in identifying the bottom signal.  The recorder was also linked to a 
clock, and thus could indicate 5 minute intervals on the sounder paper.  The 
system was used to collect bathymetric soundings at 5 minute intervals while 
underway between stations.

One transducer is positioned on a Ram that can be lowered or raised depending on 
conditions.  
The record of Ram position is as follows:

Ram up at beginning of trip 
Ram down on 1100 Z June 27
Ram up at 1307 Z July 3
Ram down at 0910 Z July 6
Ram up at 1800 Z July 6

When the ram is up, the waterline to transducer offset is 6 m.  When the ram is 
down, the offset is 8 m.


2.   Vessel Mounted Acoustic Doppler Current Profiler	Murray Scotney

The Hudson was equipped with a hull mounted RDI acoustic doppler current 
profiler.  The transducer (serial number 177) had VM ADCP electronics (serial 
number 607).  Logging, using Transect software on a 486 PC, was started on June 
22 at  2228 Z in Halifax Harbour.  The configuration of the equipment results in 
a bin length of 4 metres and a total of 128 bins.  The 5 minute averaged data 
are stored to disk and backed up every few days.  ADCP logging was stopped on 
July 9 at 1140 Z in Halifax Harbour.


3.   Continuous Flow Multisensor Package (CFMP)	Jeff Anning

Water from approximately 4m was continuously pumped to the forward lab.  The 
temperature, conductivity and fluorescence was measured and logged every 30 sec.  
Temperature and conductivity were measured with Seabird sensors and the 
fluorescence by a Wetlabs follow-through fluorometer.  Incident 
Photosynthetically Active Radiation was measured with a Li-Cor  Spherical 
Quantum Sensor and this data was merged with the sea water parameters.  Exact 
time and positions were provided by a  Northstar GPS and logged with the other 
data.  In addition discrete water samples were collected every 15 minutes by an 
auto sampler for later analysis for nitrate and silicate.  The time and position 
of these samples was also logged by the computer.


4.   XBT and XCTD

No probes were used


5.   Meteorological observations

Routine reporting of meteorological variables was carried out by the ship's 
crew. 


6.   Atmospheric Chemistry

There was no atmospheric chemistry program.

