#DATA_DATES: 1991/09/02 13:26:00 --- to --- 1991/09/22 22:38:00 #LON_RANGE: 42.51 W --- to --- 3.91 W #LAT_RANGE: 49.64 N --- to --- 64.13 N #DEPTH_RANGE: 13 --- to --- 481 m #SAC_CRUISE_ID: 00380 #PLATFORM_NAME: R/V Meteor #PRINCIPAL_INVESTIGATOR_NAME: Manfred Bersch #PI_INSTITUTION: Institute fur Meereskunde an der Universitat Hamburg #PI_COUNTRY: Germany #PROJECT: WOCE (One-time line) #CRUISE_NAME: ship_tag=M18/1 woce_tag=A01E EXPOCODE=06MT18_1 #PORTS: Reykjavik, Iceland to Hamburg, Germany #GEOGRAPHIC_REGION: North Atlantic #PROCESSED_BY: Institut fur Meereskunde, Hamburg #NAVIGATION: GPS #QUALITY_NAV: good #GENERAL_INFORMATION: CRUISE NOTES CHIEF SCIENTIST ON SHIP : Jens Meincke INSTITUTE : Institute fur Meereskunde; Hamburg COUNTRY : Germany SIGNIFICANT DATA GAPS : SPECIAL SHIP TRACK PATTERNS : COMMENTS : Excepts below from WHP report: Abstract The METEOR cruise no. 18 was aimed at contributing to the World Ocean Circulation Experiment (WOCE) in particular to the one-time survey of the WOCE-Hydrographic Programme. The survey line from Ireland to Cap Farvel crosses the North Atlantic just to the south of the major convective regimes, so that transport estimates for the warm and the cold water masses can be used to estimate the North Atlantic overturning rate. This quantity is one of the key figures for the ocean's role in climate. Measurements were carried out as outlined in the WOCE-documentation, i.e. the full suite of hydrographical and nutrient parameters and tracer substances as tritium, helium, CFCs and radiocarbon. In addition the quantities relevant to determine the ocean carbon cycle were sampled. The measurements on stratification were complemented by direct current measurements, employing an acoustic doppler current profiling system for the upper 300m and deploying long term moored current meter arrays at six locations along the survey line. The quality of the data obtained was generally confirming to the standards set by WOCE. Research Objectives The North Atlantic Ocean is characterized by an intense meridional circulation cell, carrying near surface waters of tropical and subtropical origin northwards and deep waters of arctic and subarctic origin southwards. The related "overturning" is driven by sinking of water masses at high latitudes. The overturning rate and thus the intensity of the meridional transports of mass, heat and salt is an important control parameter for the modelling of the ocean's role in climate. Certainly such estimates require more than one survey of the study area and therefore the METEOR cruise no. 18 was one in a series of cruises, which started in March 1991 and is expected to continue into 1995. This effort, which is a joint project of the Institut fur Meereskunde, University of Hamburg and the Bundesamt fur Seeschiffahrt und Hydrographie, Hamburg in cooperation with varying groups from other marine institutions, serves two purposes: On the one hand it is a German contribution to the international World Ocean Circulation Experiment, WOCE-Hydrographic-Program, in particular to the WHP one-lime survey of the eastern part of the hydrographic section A1 and the repeats thereof (ANON, 1988). On the other hand it serves the national project WOCE-NORD (North Atlantic Overturning Rate Determination). Its objective is to determine directly the overturning rates by means of seasonally repeated hydrographic sections between the southern tip of Greenland and Ireland in combination with current measurements from long-term moored arrays. The location of the section was chosen to be to the south of the major wintertime convection regions to avoid water mass formation processes and to stay away from shallow topography in order to avoid difficulties in applying the geostrophic method for volume transport estimates. The occasion of the cruise M 18 was also used to contribute to the global study of the carbonate system, which is carried out in the framework of the Joint Global Ocean Flux Study in close coordination with WOCE. ADCP INSTRUMENTATION MANUFACTURER : RDI HARDWARE MODEL : 150 SERIAL NUMBERS : FIRMWARE VERSION : TRANSMIT FREQUENCY : 153.6 kHz TRANSDUCER CONFIGURATION : JANUS CONCAVE COMMENTS : ADCP INSTALLATION METHOD/DESCRIPTION OF THE ATTACHMENT TO THE HULL : The transducers were installed in the front hull to reduce noise by propeller cavitation. LOCATION/DEPTH ON HULL : Transducer depth at nominally 5 m REPEATABLE ATTACHMENT : DATE OF MOST RECENT ATTACH. : ACOUSTIC WINDOW : COMMENTS : ADCP INSTRUMENT CONFIGURATION DEPTH RANGE : 11 to 481 m BOTTOM TRACKING : at times on shelf CONFIGURATION HISTORY Columns are as follows: B : CODAS logical block number SI : sampling interval or averaging period for ensemble (sec) BL : bin length (m) PL : pulse length (m) - assumed equal to bin length, not confirmed TD : transducer depth (m) - not confirmed BK : blanking length (m) - not confirmed yyyy/mm/dd hh:mm:ss B SI NB BL PL TD BK 1991/09/02 13:26:52 0 60 30 4 4 4 4 1991/09/02 13:49:17 1 120 30 4 4 4 4 1991/09/02 18:48:27 2 240 30 4 4 4 4 1991/09/02 18:58:38 3 240 30 8 8 4 4 1991/09/03 08:29:16 4 240 30 16 16 4 4 1991/09/21 20:43:17 20 240 30 8 8 4 4 Note, the blanking length is incorrect in the CODAS blocks (it is noted as 3m, it is actually 4m). ADCP DATA ACQUISITION SYSTEM SOFTWARE DEVELOPERS : RDI SOFTWARE VERSIONS : DAS 2.48 DATA LOGGER, MAKE/MODEL : PC ADCP/LOGGER COMMUNICATION : USER BUFFER VERSION : unconfirmed CLOCK : unconfirmed COMMENTS : SHIP HEADING INSTRUMENT MAKE/MODEL : gyro SYNCHRO OR STEPPER : SYNCHRO RATIO : COMPENSATION APPLIED : no GPS ATTITUDE SYSTEM : no LOCATION OF ANTENNAS : RIGID ATTACHMENT : LOGGING RATE : ANCILLARY MEASUREMENTS SURFACE TEMP AND SALINITY : unconfirmed PITCH/ROLL MEASUREMENTS : HYDRO CAST MEASUREMENTS : yes BIOMASS DETERMINATION : no DATE OF LAST CALIBRATION : CALIBRATION COEFFICIENTS : BEAM-AVERAGED AGC AVAILABLE?: CALIBRATION NET TOWS? : COMMENTS : ADCP DATA PROCESSING/EDITING PERSONNEL IN CHARGE : A.Bersch DATE OF PROCESSING : ADDED TO NODC DB : JAN 2000 NOTABLE SCATTERING LAYERS : COMMENTS : Profile editing performed using IFM,Hamburg software. Bottom reflection and wire interference cleaned as necessary. NAVIGATION GPS : YES MAKE/MODEL : Magnavox SELECTIVE AVAILABILITY : P-CODE : DIFFERENTIAL : no SAMPLE INTERVAL : LOCATION OF ANTENNA RELATIVE TO TRANSDUCER : TIME OBTAINED RELATIVE TO START/END OF ENSEMBLE : unconfirmed AVERAGING/EDITING APPLIED : yes, bad fixes edited out LOGGED WITH ADCP DATA : yes LOGGED INDEPENDENTLY : yes COMMENTS : OTHER : CALIBRATION GYROCOMPASS CORRECTION : no BOTTOM TRACK METHOD : YES WATER TRACK METHOD : YES COMMENT : explicit phase/amplitude values for transducer misalignment and scale factor are not available NAVIGATION CALCULATION NAVIGATION USED : GPS REFERENCE LAYER DEPTH RANGE : unconfirmed FILTERING METHOD FOR SMOOTHING REFERENCE LAYER VELOCITY (FORM/WIDTH) : Blackman window function FINALIZED SHIP VEL/POSITIONS STORED IN DATABASE : YES COMMENTS : REFERENCES (DATA REPORTS,ETC.) : Bersch (1995), Deep-Sea Research, 42, 1583 - 1607.