WFP Ref. No.: AR5, AR7, A20N, A4C
Last Updated: July 8, 1991



Location:		Western North Atlantic Ocean and southern Labrador Sea.
Dates:		24 April - 24 May, 1991 (91-007)
26 May - 4 June, 1991 (91-015)
Ship:			C.S.S. Hudson
Expocode:		18HU91007, 18HU91015
Cruise No./Leg:	91-007/ 91-015
Senior scientist(s):	Dr. R.M. Hendry
Marine Services Division
Physical and Chemical Sciences Branch
Scotia-Fundy Region
Bedford Institute of Oceanography
P.O. Box 1006
Dartmouth, Nova Scotia
CANADA B2Y 4A2

Scientific project leader(s):	Dr. R.M. Hendry
                               			Dr. E.P. Jones
                              			Dr. E.P.W. Horne

Itinerary Accomplished:

Dep:  Dartmouth, N.S.	Arr: Julianehaab, Greenland 
Wed. Apr 24, 1991		Fri. May 24, 1991 

Julianehaab               	Dartmouth 
Sun. May 26, 1991         	Tue. June 4, 1991

Summary of Purpose:

The primary purpose of Cruises 91-007 and 91-015 was to map the
distribution of temperature, salinity and various chemical properties along
selected sections in the western North Atlantic and southern Labrador Sea
as part of the international World Ocean Circulation Experiment (WOCE)
Hydrographic Program. The overall goal of this work is to better understand
and model the role of ocean circulation and the associated transports of
heat and fresh water in the global climate system. 

At the same time, measurements of alkalinity, total carbonate,
chlorofluorocarbons (CFC's) and other anthropogenic trace gases found in
seawater were undertaken to better understand the transport and storage of
these gases in the ocean. This work was partly supported by the
Interdepartmental Panel for Energy Research and Development (PERD) program
on Climate and CO2. It also contributes to the international Joint Global
Ocean Flux Study (JGOFS) examining the role of the oceans in the global
carbon budget. 

Further work in support of JGOFS was undertaken by Biological
Sciences Branch (BSB) through measurements of primary biological production
and associated physical and chemical oceanic variables. 

Researchers from Dalhousie University Department of Oceanography
measured the distribution of methyl chloride and bromoform in seawater to
begin to understand the sources for these gases and their linkages with
biological activity. 

Type of data collected:

Temperature, salinity and dissolved oxygen data were collected
using our own CTD instrumentation on all stations, and using up to three
trial CTD units on selected stations. Water samples collected by Rosette 
sampler using 8-liter sampling bottles were analyzed on board ship for
salinity, dissolved oxygen, nutrients (phosphate, silicate, nitrate 
plus nitrite), alkalinity, total carbonate, chlorofluorocarbons
(CFC-11, CFC-12, CFC-113), carbon tetrachloride, methyl chloride
and bromoform.  Station measurements of nutrients, chlorophyll and
primary production in the upper 100m were measured with a submersible pump
system (BSB). Station measurements of light attenuance and fluorescence
were measured by a new design of profiling light meter (BSB). Underway 
measurements of near surface currents were obtained using an
Ametek/Straza acoustic doppler current profiler. Underway measurements of
near surface temperature, salinity and fluorescence were made using the
ship's sea water intake (BSB). Atmospheric particulates were collected 
by pumping air through filters for shore-based analysis (Dalhousie
University). 

Scientific or Survey Accomplishments:
(with statements explaining failures to achieve objectives)

130 CTD stations were occupied along a 5000 nm cruise track.
> 2600 discrete water samples were collected.

Stations were occupied as planned except for the final stations
planned on the Labrador Coast where ice conditions made passage impossible.
Good coverage was obtained in the East Greenland Current and West Greenland
Current in spite of the presence of some ice. Minor hardware problems with
our CTD systems meant that a total of three sea units were used, and the
final calibration of the data will be correspondingly complicated. 

About 2500 determinations of dissolved oxygen and nutrient concentrations.
> 2000 determinations of total carbonate concentrations.
> 1000 determinations of CFC concentrations.
> 1000 determinations of total alkalinity. 

Very few problems were associated with the analytical systems
themselves. Most problems that did occur were traced to failures of small
components. All laboratory measurements were jeopardized to some degree by
poor temperature control of the laboratories. Rapid and large changes in
temperature caused difficulties with baseline drift and calibration for
nutrients, and calibration difficulties together with poorer precision for
the CFC, total alkalinity, and total carbonate measurements. Salinity
analyses were also affected. The CFC analyses also suffered somewhat
because of shipboard CFC-12 contamination. 

Biological Sciences were able to make measurements in intensive
spring bloom conditions and a unique set of biological and physical
measurements were obtained.

The Dalhousie University researchers accomplished one of the first
systematic marine surveys for methyl chloride and bromoform. Their future
analyses will be well-supported by the physical and biological measurements
made on the cruise. 

Parameter:
Scientific Personnel:
Chief scientist
Dr. R.M. Hendry  (902) 426-3142
CTD data 
Ocean Circulation Division

Bedford Institute of Oceanography 


chlorofluorocarbons &  
Dr. E.P. Jones  (902) 426-3869
carbonate chemistry

nutrients  
Mr. P. Clement  (902) 426-3669
chlorofluorocarbons  
Dr. R. Gershey  (902) 426-4147

Marine Chemistry and Toxicology Division
 
Bedford Institute of Oceanography 
  

biological program
Dr. E.P.W. Horne (902) 426-8362

Biological Oceanography Division

Bedford Institute of Oceanography 


bromoform chemistry  
Dr. R. Tokarczyk (902) 494-3671
methyl chloride chemistry 
Ms. V. Tait (902) 494-3671

Department of Oceanography

Dalhousie University

Halifax, Nova Scotia
 
CANADA B3H 4J1


Stn
Cast
Start
Start
Latitude
Longitude


Date
Time (UTC)
deg min
deg min
A20N - 28 Stations
2
1
04/27/91
08:34
N 43  14.91
W 50  15.09
29
1
05/04/91
09:15
N 33  0.06
W 50  14.98

A4C - 15 Stations
30
1
05/04/91
16:43
 N 32  59.93
 W 49  34.79
44
1
05/08/91
10:15
 N 32  59.99
 W 40  15.13

AR5 - 62 Stations
45
1
05/08/91
16:31
 N 33  29.94
 W 39  46.94
105
1
05/23/91
03:24
 N 59  7.05
 W 42  12.52

AR7 - 25 Stations
106
1
05/26/91
16:49
 N 60  32.02
 W 48  5.17
130
1
05/31/91
21:16
 N 54  54.98
 W 54  2.82



