WHP Ref. No.: AR4E/AR4W/AR15
Last updated: 15 December 1994

				Cruise report 
			Meteor cruise 27, leg 3

A.	 Cruise narrative

A.1.	 Highlights
a.	 WOCE designation: 	AR4E, AR4W, and AR15
b.	 Expedition designation:06MT27/3
c.	 Chief scientist: 	Prof. Dr. F. Schott
				Institut fr Meereskunde
				Universitat Kiel
				Dusternbrooker Weg 20
				24105 Kiel, Germany
				Telephone: +49-431-597-3820
				Telefax: +49-431-597-3821
				Telex: 17431793 IFMKIEL
d.	 Ship: 			R/V Meteor
e.	 Ports of call: 	Ponta Delgada, Azores to Recife, Brazil
f.	 Cruise dates: 		February 19 to March 26, 1994

A.2.	 Cruise Summary Information

a.	 Geographic boundaries: Stations were taken along AR4W (46W) from 
the equator to 11N and AR4E (35W) from 5S to 430N. Additional stations 
were taken in the AR15 area within the area 10S to 11N and 30W to 44W. A 
track chart is available from the WHPO.

b.	 Stations occupied: A total of 110 CTD/rosette stations were 
occupied during the cruise. Of these, 24 stations were done along AR4W, 16 
were done along AR4E, and the remaining 70 were done in the AR15 Deep Basin 
Experiment - Brazil Basin area.
Water sampling on the cruise included measurements of salinity, both by CTD 
and bottle sample oxygen determinations, CTD temperature. Tracer analysis 
were made for F-11 and F-12.

c.	 Floats and drifters deployed:  None reported

d.	 Moorings deployed or recovered: An essential objective was to 
retrieve three moorings along the western boundary near 44W. Two moorings 
could be retrieved intact on 4 March and the third one on 5 March.

A.3.	 List of Principal Investigators

Parameter/Instrument 	Sampling group	Responsible Investigator
CTD/O2 / Rosette	IfM Kiel	Lothar Stramma
Chlorofluorocarbons	IfM Kiel	Monika Rhein
ADCP			IfM Kiel	Jurgen Fischer
Pegasus			IfM Kiel	Gerd Krahmann
Salinity		IfM Kiel	Lothar S~ramma
Oxygen			IfM Kiel	Monika Rhein
XBTs			IfM Kiel	Lothar Stramma
Mooring recovery	IfM Kiel	Friedrich Schott

A.4.	 Scientific Programme and Methods

Leg 3 of METEOR cruise 27 focussed on the investigation of the circulation 
and the water mass exchange in the western tropical Atlantic. This 
investigation was carried out in the context of the World Ocean Circulation 
Experiment (WOCE). The cruise was a follow-up study to the investigations 
carried out during METEOR cruises M 14/2 in October 1990, M 16/3 in May/June 
1991 and M 22/2 in November 1992. The western tropical Atlantic plays an 
important role in the water mass exchange between the northern and the 
southern hemispheres. The meridional heat transport takes place by warm 
surface waters and subpolar intermediate waters from the southern hemisphere 
moving northward in the upper 1000 m, and North Atdantic Deep Water (NADW) 
moving southward between 1200 and 4000 m. The details of this water mass 
exchange across the equator and the seasonal changes of the flow field are 
not well understood, and were the main subject of this cruise.

Due to some repairs in Lisbon, METEOR departed one day behind schedule out 
of Ponta Delgada, on 19 February 1994 16:00 local time. In the morning of 24 
Feb., a test station was operated where CTD and die lowered ADCP (LADCP) 
were found to operate satisfactorily. During the crossing of the Vema 
Fracture Zone, three deep stations with CTD/LADCP were run across the 
channel (see Figure). During 27-28 February a deep section from the Mid-
Atlantic Ridge (MAR) to the Ceara Rise across the Guiana Basin was carried 
out to measure the deep boundary current there and possibly recirculation 
west of the MAR.

An essential objective was to retrieve three moorings along the western 
boundary near 44W. Two moorings could be retrieved intact on 4 March and 
the third one on 5 March. In between mooring work, CTD/LADCP stations were 
continued and on Saturday, 5 March, the 44W section was completed. The work 
on the 40W section began on 7 March.

At the northern end of that section, a northwesterly leg was attached to 
connect with the southeastern flank of the Ceara Rise and cut across the 
deep boundary flow there. On 13 March the 35W section was begun at 430N 
with shallow (to 2200m) stations over the MAR, southward to 1N. All 8 
Pegasus transponder pairs along 35W, deployed in fall 1990 and spring 1991, 
were still operational, and good profiles were obtained at those stations. 
On 18 March, measurements in the boundary currents off Natal near 540S 
were begun. The connection from the 5S to the 10S sections was occupied by 
6 deep stations. The southward leg was terminated in the morning of 23 
March, and the work at the last section, along 10S, began. The last CTD 
station was made on March 25, and the ship arrived in Recife in the morning 
of March 26, 1994, where the cruise M27/3 ended.

A.5.	 Major Problems and Goals Not Achieved
None reported.

A.6.	 Other Incidents of Note
None reported.

