METEOR-Cruise 37/2

Cruise Report

# 

# Abstract

Leg 37/2 was performed within two major projects of basic marine
research. CANIGO (Canary Islands Azores Gibraltar Observations) is a
multinational project funded by the European Union to investigate by
field experiments and modelling the circulation and watermasses in the
subtropical eastern North Atlantic and to determine the distribution and
the fluxes of a diversity of parameters in this region. ESTOC is a
European time series station that has been set up since 1994 in a joint
effort of four institutes from Spain and Germany 60 nm north of Gran
Canaria and Tenerife, and that serves as a background station for
CANIGO. The aim of leg 37/2 was to exchange and set moorings with
current meters and sediment traps at selected positions at which
currents and vertical particle fluxes are to be measured directly for
several months. These moorings are part of a closed box of 45 stations
north of the Canary Islands from which balanced fluxes will be
calculated in using geostrophic currents adjusted to absolute profiles
of ADCP measurements.

# Zusammenfassung

Der Fahrtabschnitt M37/2 war Teil von zwei großen Projekten in der
marinen Grundlagenforschung. Die Europäische Union fördert das
multinationale Projekt CANIGO (Canary Islands Azores Observations).
Hauptziel ist es, Zirkulation und Wassermassentransporte im
subtropischen östlichen Nordatlantik und die damit zusammenhängenden
Flüsse mehrerer bio-geochemischer Parameter mit Hilfe von direkten
Beobachtungen und von Modellen zu bestimmen. Im einem spanisch-deutschen
Projekt wird seit 1994 die Zeitserienstation ESTOC etwa 100 Km nördlich
von Gran Canaria und Teneriffa betrieben. Während M37/2 sollten
verankerte Strömungsmesser und Partikelfallen an ausgewählten Positionen
erstmals ausgesetzt bzw ausgetauscht werden. Mit ihnen werden die
vertikale Struktur von Strömung und Sedimentationsraten bestimmt. Die
Verankerungspositionen waren gleichzeitig Teil einer geschlossenen Box
von 45 Stationen nördlich der Kanrischen Inseln und östlich von Madeira.
Ziel ist es, Balancen von Flüssen verschiedener Parameter zu berechnen.
Dabei werden gestrophisch berechnete Strömungsprofile mit Hilfe von
direkten Strömungen aus ADCP-Messungen an absolute Profile angepaßt.

Compiled by Thomas J. Müller

Institut für Meereskunde an der Universität Kiel

Düsternbrooker Weg 20

24105 KIEL, Germany

Phone : ++431 597 3799

Fax : ++431 597 3981

e-mail : tmueller@ifm.uni-kiel.de

# Contents 

Page

1 Research Objectives leg M37/2 3

2 Participants leg M37/2 4

## 3 Research Programme leg M37/2 6

## 4 Narrative of the Cruise leg M37/2 7

## 5 Preliminary Results leg M37/2 9

5.1 Physical and Chemical Oceanography 9

5.2 Particle flux process studies at ESTOC 10

5.3 Trace metal measurements at ESTOC, EBC and LP1 12

5.4 Measurements of Foraminifera during M37/2a 13

5.5 Bio-Optical mesurements on the CANIGO box 15

5.6 Measurements of Al and other trace metals on the CANIGO box 17

5.7 Measurements of CO~2~ parameters on the CANIGO box 19

5.8 Measurements of DOC on the CANIGO box 19

5.9 Measurements of Cocolithophores and Foraminifera on the CANIGO box
20

5.10 Zooplankton as tracers in intermediate waters off Morocco at 29°N
and 32°N 21

## 6 Ship's Meteorological Station leg M37/2 24

## 7 Lists 25

7.1 METEOR 37/2 station and sample log 25

References 29

Figure captions 30

Figures 31

# 1 Research objectives leg M37/2

The area north of the Canary Islands and until the latitude of Madeira
is characterized in the upper layers by recirculating branches of the
North Atlantic's subtropical gyre that feed the Canary Current and that
are influenced by upwelling events off the African coast. This leg of
Meteor cruise 37 was aimed at studying the circulation and transports of
water masses, the associated fluxes of bio-geochemical parameters in the
water column and through the air sea surface in this area and their
variability in space and time. The work was embedded mainly in two major
interdisciplinary and multinational projects: the European funded marine
science and technology project CANIGO (Canary Islands Azores Gibraltar
Observations) and the Spanish German ocean time series station ESTOC 100
Km north of Gran Canaria.

Methods included to use moored current meters and sediment traps to
study the vertical structure of the eastern boundary current and
sedimentation rates of a diversity of bio-chemical parameters at three
key sites (Fig. 1, upper panel): (i) in an array of 5 moorings (EBC)
east of Fuerteventura / Lanzarote, an area that is strongly influenced
bay upwelling, (ii) at the open ocean time series station ESTOC which
serves also as a background station for CANIGO, and (iii) at the more
oligothophic station LP1 north of La Palma.

To estimate the spatial structure and variability of fluxes in the
recirculation regime, a hydrographic box of 45 stations was obtained
north of the Canary Islands (Fig. 1, lower panel) to estimate transports
of waters masses and bio-chemical parameters. Classic hydrography along
with direct current measurenments from lowered and ship mounted ADCP was
used. Samling included also CO~2~ parameters, DOC, Al and other trace
metals, coccolithophores and diatoms, and zooplankton and fish larvae.

# 2 Participants leg M37/2

For logistic reasons, the leg had two parts:

**Leg 37/2a: Las Palmas-Las Palmas, 28.12.1996-05.01.1997**

**37/2b: Las Palams-Las Palmas, 06.01.1997-22.01.1997**

Leg M37/2

a b

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

Müller, Thomas J. Dr. IFMK Chief Sc. \-\-\-\-\-\-\-\-\-\-\-\-\-\--

Beining, Peter Dr. IFMK Phys. Oc. \-\-\-\-\--

Busse, Markus Stud. IFMK Phys. Oc. \-\-\-\-\-\-\-\-\-\-\-\-\-\--

Cisneros-A., Jesus MSc. ULPGC Phys. Oz. \-\-\-\-\--

Garcia-R., Carlos MSc. IEO Phys. Oz. \-\-\-\-\--

Hernandez-G., Alonso Dr. ULPGC Phys. Oc. \-\-\-\-\--

Kipping, Antonius TA IFMK Moorings \-\-\-\-\--

Koy, Uwe TA IFMK CTD, floats \-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

Lopez.-L., Federico MSc IEO Phys. Oc. \-\-\-\-\--

Meyer, Peter Dipl-Ing IFMK Moorings, CTD\-\-\-\-\-\-\-\-\-\-\-\-\-\--

Rose, Henning Dipl-Phys UBT Tracer Oc. \-\-\-\-\--

Schuster, Connie TA IFMK Phys. Oc. \-\-\-\-\--

Neuer, Susanne, Dr. GeoB Part. flux \-\-\-\-\--

Kemle-v. Mücke, S. Dr. GeoB Foraminifera \-\-\-\-\--

Darling, Kate Dr. UoE Foraminifera \-\-\-\-\--

Stewart Ian Stud. UoE Foraminifera \-\-\-\-\--

Otto, Sabine Dr. UBMCh Trace metals \-\-\-\-\--

Deeken, Aloys A UBMCh Trace metals \-\-\-\-\--

Kukolka, Florian Stud. UBMCh Trace metals \-\-\-\-\--

Correira, Antonio TA UL Diatomees \-\-\-\-\--

Bollmann, Jörg Dr. ETH Cocolithoph. \-\-\-\-\--

Barth, Hans Dr. UO Marine optics \-\-\-\-\--

Zielinski, Oliver Dipl-Phys UO Marine optics \-\-\-\-\--

Loquay, Klaus TA UO Marine optics \-\-\-\-\--

Hernandez-B., Joaquin Dr. ULPGC Trace metals \-\-\-\-\--

Gelado C., Maria MSc. ULPGC Trace metals \-\-\-\-\--

Munoz, Francisco Stud. ULPGC Trace metals \-\-\-\-\--

Mintrop, Ludger Dr. GeoB CO2 \-\-\-\-\--

Gonzalez-D, Melchior Dr. ULPGC ph, Alkalin. \-\-\-\-\--

Perez, Fiz Dr. CIMV CO2 \-\-\-\-\--

Friis, Karten Stud. IFMK CO~2~ \-\-\-\-\--

Cianca-A, Andres MSc. ICCM Marine chem. \-\-\-\-\--

Godoy, Juana MSc. ICCM Marine chem. \-\-\-\-\--

Perez-M., Francisco MSc ICCM Marine chem. \-\-\-\-\--

Villagarcia, Maria Dr.. ICCM Marine chem. \-\-\-\-\--

Fengler, Günther Dr. IBGM DOC \-\-\-\-\--

John, Hans-Christian Dr. BAH Zooplankton \-\-\-\-\--

Zelck, Clementine Dipl.-Biol. BAH Zooplankton \-\-\-\-\--

## Participating Institutions

IFMK Institut für Meerekunde an der Universität Kiel, Germany

CIMV Consejo Superior de Investigaciones, Instituto de Investigaciones
Marinas, Vigo, Spain

BAH Biologische Anstalt Helgoland, Hamburg, Germany

GeoB FB5 Geowissenschaften, Universität Bremen, Germany

IBGM Institut für Biogeochemie und Meereschemie der Universität Hamburg,
Germany

ICCM Instituto Canario de Ciencias Marinas, Telde, GC, Spain

IEO Instituto Espanol de Oceanografia, Sta. Cruz, TF, Spain

UBMCh FB2 Biologie/Chemie - Meereschemie-, Universität Bremen, Germany

UBT FB1 Physik, Universität Bremen, Germany

UL Instituto de Oceanografia, Unversidade de Lisboa, Portugal

ULPGC Universidad de Las Palmas de Gran Canaria, Las Palmas, GC, Spain

UO Universität Oldenburg, FB Physik, Germany

UoE University of Edinburgh, Scotland, United Kingdom

## 3 Research programme leg M37/2

Along the CANIGO and ESTOC scientific goals, METEOR cruise M37/2 was
aimed at providing a data base for studying the circulation and water
mass transports in the subtropical eastern North Atlantic north and east
of the Canary Islands. The region encompasses the eastern boundary
current system. Determining the variability of the circulation and
associated bio-geochemical fluxes on time scales from days to annual and
longer, and on spatial scales that include the mesoscale (30 Km) up to
basin scale is included. The flow field, the water mass transports and
the associated bio-geochemical fluxes in the region are strongly
influenced by both, the recirculation of the subtropical gyre that feeds
the Canary Current and the seasonally varying trade wind field with its
impact on the upwelling system and the eastern boundary current system
off Marocco.

To attack the problem, basicly two methods are used. First, at selected
positions the vertical structure of currents and the vertical transport
of particles are measured for a period of ca 18 months from January 1997
on to cover more than one season. The sites chosen (see Fig. 1) are the
ESTOC position, an array of five moorings in the eastern boundary
current sytem (EBC) east of Lanzarote and Fuerteventura that will be
influenced strongly by upwelling events, and a more oligithrophic open
ocean position north of La Palma (LP1). Current meters and sediment
traps will be moored, with a service of instruments scheduled for autumn
1997 from the German reserach vessel POSEIDON. During the first part of
M37/2, it was planned to

-   exchange the ESTOC current meter mooring (IFMK)

-   to set the five moorings array EBC (IFMK, IEO, ULPGC, GeoB)

-   to set a mooring at site LP1 (GeoB, IFMK)

-   to measure the vertical particle flux in the upper 200 m near ESTOC
    and at the same time to perform incubation experiments (GeoB)

-   to measure the concentraions and vertical fluxes of certain trace
    metals at the ESTOC, EBC and LP1 sites (UBMCh)

-   to take samples for CFCs as reference for the time varying input
    function at ESTOC (UBT)

-   to determine the near surface distribution of foraminifera (GeoB,
    UoE)

Second, a closed box north and east of the Canary Islands is designed
with 45 hydrographic stations spaced between 7 nm on and close to the
shelf, and 40 nm in the deep basin. On each station, bottom deep CTD and
lowered ADCP measurements and water sampling for dissolved oxygen,
nutrients and chlorophyll analysis build the basic hydrographic
measurements to determine the flow field and the water mass
distribution. Enroute, the upper ocean current profiles down to 200 m
and the sea surface temperature and salinity are measured using a vessel
mounted ADCP and a thermosalinograph in combimation with GPS
positioning. These basic measurements on the box will be repeated in in
autumn 1997 and spring 1998 with POSEIDON, and in summer 1998 with
METEOR. During the second part of M37/2 these and additional samples
were taken and measurements were made to

-   to determine the absolute flow field and with a CTD/rosette/ADCP
    system and with shipborne ADCP (IFMK)

-   to provide water mass information from oxygen, nutrient and
    chlorophyll (ICCM)

-   to use optical sensors attached to a CTD for biological
    interpretations (UO)

-   to measure parameters of the CO~2~ system in the water column and at
    the air sea interface (IFMK, CIMV, ULPCG)

-   to take samples for dissolved organic carbon DOC (IBGM)

-   to take samples for coccolithophores and diatomees (ETH, UL)

-   to measure aluminum and other metals in the water column (ULPGC)

-   to detect fish larvae as tracers for intermediate water masses (BAH)

## 4 Narrative leg M37/2

For logistic reasons, this leg was divided into two parts. After loading
of scientific equipment and embarking of the scientific party, METEOR
sailed from Las Palmas on the 28 December 1996 in the afternoon. This
first part, leg M37/2a, was aimed at mooring and station work near the
centre of the CANIGO array in the eastern boundary current system (EBC),
at the ESTOC station and at the more oligotrophic CANIGO position LP1
north of the island of La Palma. Here, special water sampling was
performed for trace metal analysis. Near ESTOC, an experiment was
designed to determine the vertical flux of particles in the surface
layer. On station, plankton was caught from near the surface using pumps
and handhold nets. Additional CTD stations between the mooring positions
completed the hydrographic work. En route, meteorological data, sea
surface temperature and salinity were measured almost continuously from
the ship-borne thermosalinograph. Unfortunately, we could not measure
the vertical current profiles due to a failure of the ADCP mounted on
the ship's hull. A spare was available only later for leg M37/2b.

About 4 hours after sailing for legM37/2a, we successfully performed a
test station with a CTD/rosette sytem. Attached to the CTD/rosette were
two acoustic releases of IFMK to test for later use in moorings.

Early in the morning next day, we arrived at the ESTOC station position
at nominally 29°10'N, 15°30'W and 3610 m water depth. Here, after a
CTD/rosette cast, the first two of five casts with special bottles and
pumps for trace metal sampling were obtained to achieve a densely
sampled profile throughout the the water column. Between these casts, at
a position some 10 nm northeast of ESTOC a drifting sediment trap was
deployed to measure for a few days the particle flux in the upper 200 m
layer.

We then steamed to the position of the first of five CANIGO moorings
that we deployed in the eastern boundary current array EBC on the 30 Dec
and 31 Dec 1996 during day time. The five moorings all reach up to 150 m
below the surface and carry a total of 23 current meters and 2 sediment
traps. During the night and between the moooring work, five CTD stations
near the mooring positions and three hydrocasts for a trace metal
profile near mooring EBC3 were obtained. The CTD stations form a section
across the channel between Lanzarote/Fuerteventura and the Moroccian
shelf.

While steaming again to the ESTOC station, we celebrated New Year's Eve
with a mixture of German and Spanish traditions. On New Year's Day
morning, the third of five trace metal casts and a shallow CTD/rosette
profile for water sampling at the ESTOC position was obtained. We then
searched successfully for the drifting sediment trap for recovery. After
almost immediate redeployement of the trap, another shallow CTD/rosette
was taken to supply water for the incubation experiment that runs while
the trap is drifting. In the afternoon, the ESTOC current meter mooring
was successfully recovered after 15 months. All meters have worked. The
fourth and fifth trace metal cast and a CTD/rosette cast close to the
bottom with CFC sampling were obtained during the night.

We then steamed towards the position LP1 north of the island of La Palma
at nominally 29°45'N, 18°00'W. We reached that position on 02 Jan 1997,
performed another test with an acoustic release attached to the
CTD/rosette, took the first two of three trace metal casts and a deep
CTD/rosette cast. On 03 Jan 1997 we deployed CANIGO mooring LP1 with two
sediment traps and three current meters. The final trace metal cast
completed the work at this position..

Heading again for the ESTOC position, we took four CTD stations down to
2000 m below the Mediterranean outflow water to achieve additional
information on the thermocline circulation north of the Canary Islands.
The ESTOC current meter mooring was set and the drifting sediment trap
successfully recovered on 04 Jan 1997. Five CTD stations towards
Lanzarote/Fuerteventura completed a section that starts at the African
shelf, passes the current meter array EBC and the ESTOC position and
reaches to the mooring position LP1.

METEOR called port of Las Palmas on 05 Jan 1997 for personnel exchange.
The groups from the IEO, ULPGC, GeoB, UBMCh, UBT and UoE involved in
mooring work, trace metals, CFC and foraminifera disembarked. Embarking
were groups from eight institutes from four nations.

METEOR sailed from Las Palmas for Leg M37/2b on 06 Jan 1997 in the
evening. In port, a spare ADCP had been mounted in the ship's moon pool
for enroute upper ocean direct curent measurements. Leg M37/2b was aimed
to measure and sample important hydrographic, chemical and bilogical
parameters on a closed box north of the Canary Islands for balance and
flux calculations. In addition to the upper ocean enroute current
profile and sea surface temperature and salinity, pCO2 was measured by
pumping water from the pool.

After a test station late in the evening on the same day, station work
started on 07 Jan 1997 east of Lanzarote and Fuerteventura on the shelf
at 100 m water depth with a station spacing of 7 nm that was increased
to 20 nm towards the ESTOC position. Each station consisted of a bottom
deep CTD/rosette cast with sampling for dissolved oxygen, nutrients and
chlorophyll. Attached to the CTD/rosette was an ADCP to measure the
absolute current profile in the whole water column. Also on each
station, another CTD with optical sensors attached took casts down to
2000 m. Samples for the CO2 sytem, dissolved organic carbon, aluminum,
coccolithophores and plankton were taken from the rosette bottles on
roughly every other station. Deep plankton net hauls down to 1000 m and
on some stations down to 2000 m were restricted to the continental shelf
break and the adjacent deep basin.

The box basicly consists of three CTD/rosette sections: the first runs
almost zonally along mooring array EBC towards ESTOC and then to a
position north of La Palma at 29°10'N, 18°00'W, the second meridionally
towards Madeira until 32°15' N, the third then zonally onto the shelf
until the 100 m bottom contour. A total of 45 stations were obtained on
these three sections. The box was then completed with enroute ADCP
measurements that ran soutwestward and almost parallel to and on the
shelf break towards the EBC array.

The routine station work was interrupted by several events. First, on
the westbound section a helicopter from the regional Canary Islands
rescue basis supplied with a chemical that was essential for the oxygen
standardization. The chemical that had been brought onboard in port had
turned out not to fulfill its specifications. Next, on the southwest
corner of the box, we had to interrupt the station work for several
hours due to gale winds. On the northbound section, two RAFOS floats
were launched to 1000 m nominal depth within the EU funded EUROFLOAT
programme. Three further floats were launched on the northern eastbound
section, the third one of these (No. 214) was positioned as to be caught
by Meddy 'Jani' that was detected by CTD measurements on station 63 at
32°15'N, 12°10.1'W. Also, a sound source (SQ4/V379) was moored on this
section at 32°16' N, 13°12' W to improve tracking of RAFOS floats that
drift towards the Canary islands within the CANIGO and EUROFLOAT
projects.

After having completed a final ADCP section that closed the box along
the 200 m depth contour off Morocco, METEOR again headed towards the
ESTOC position to obtain an XBT section with six launches from here
towards Gran Canaria. This section is part of the regular monthly ESTOC
station work performed by the ICCM. Leg M37/2b was completed in Las
Palmas on 22 Jan 1997 early in the morning.

## 5 Preliminary results leg M37/2

### [5.1 Physical Oceanography]{.underline}

(T.J. Müller, P. Beining, M. Busse, A. Cianca, J. Godoy, J. Perez, J.
Reppin, M. Villagarcia)

# Moorings

All moorings but the ESTOC current meter mooring V367200 were set for
the first time period. Therefore, data from these will be available only
after instrument service in autumn 1997. Mooring V367200 was the second
recovery of IFMK's current meter mooring at the ESTOC position. The data
return was good. Calibration of Aanderaa current meters RCM8 and that of
the ADCP follow the manufacturer's instructions (RDI, 1989; Aanderaa,
1995). The pressure record in the uppermost instrument shows that
mooring motion was low (less 20 dbar). Salinity was derived from
measured temperature and conductivity, and nominal pressure (instrument
depth). All temperature measurements and the derived salinities were
checked against CTD temperature profiles taken before laying and after
rcovery. Linear corrections were applied where necessary. After
calibration, the time series were low pass filtered with a cut off
period of 36 h and then averaged to daily values.

Displayed in Figure 2 are the combined series of currents from the two
settings which start in autumn 1994. No clear signal of a steady
southward flowing Canary Current can be detected in the upper layers.
Instead, the signals in the whole water column are dominated by
mesoscale activity, some with a strong baratropic component. Note, that
during the 27 month period, at least two meddies passed the ESTOC
position.

# Hydrography

A Neil Brown MKIIIB CTD (IFMK internal code NB2) was used to obtain
continous profiles of temperature and salinity. Attached to the CTD was
also an oxygen sensor. This sensor did not have an internal temperature
which makes absolute calibration of this sensor difficult. On some
stations, also a fluorometer was attached (see 7.1). Also attached on
most of the stations was a (lowered) lADCP.

The CTD's pressure and temperature sensors were calibrated in the
laboratory to WOCE standards (better 2 mK, 3 dbar at 6000 dbar). The
conductivity sensor was calibrated by comparison with the in-situ
conductivity of bottle samples taken during the up profile with the
rosette. CTD data processing and removal of typical nonlinear effects in
sensor responses followed Müller et al. (1995). The samples were
analysed with a Guildline AUTOSAL salinometer to better 0.002 psu for
single samples, with a few outliers being ignored. The resulting
deviations of calibrated CTD salinity from bottle salinity in up
profiles is shown in figure 3. The expected error of salinity in CTD
profiles is expected to be less 0.002 psu.

On the CANIGO box, nearly all bottle samples were analysed for oxygen
and nutrients. Analysis for dissolved oxygen used the Winkler method
with improvements to WOCE standards (WOCE Operations Manual, 1994).
Samples for nutrient analysis were frozen at -20°C and then analysed at
the ICCM following the WOCE standards (WOCE, 1994). For details see the
first ESTOC time series report (Llinas et al., 1997).

As a first result, we display the distribution of potential temperature
and salinity along the three sides of the CANIGO box (Fig. 3). Between
Lanzarote and the African shelf and centered at about 800 m depth below
the North Atlantic Central Water, we identify the Antarctic Intermediate
Water with its salinity minimum and silicate maximum (not shown here).
It probably is transported northwards with a poleward undercurrent and
cannot be identified in salinity further north at 32°N. The
Mediterranean Water with the salinity maximum at 1100 dbar to 1200 dbar
is most pronounced in Meddy 'Jani' observed on the 32°N section. Outside
this Meddy, the salinity maximum generally deceases to the south and
west.

# Direct shipborne current measurements

Attached to the CTD/rosette sytem was a 150 Khz ADCP. Lowered during CTD
casts (lADCP), it measures currents relative to the vessel from which
together with GPS positioning absolute currents in the water column can
be derived (Fischer and Visbeck, 1993).

Another 150 Khz ADCP was mounted in the ship's moonpool (vADCP) to
continously measure current profiles in the upper 300 m. In figure 5, we
display the current distribution in the upper levels. Again, no clear
Canary Current can be detected, probably because the tides have not yet
been removed from the signal.

### [5.2 Particle fluxes]{.underline}

(S. Neuer)

# Process studies near ESTOC with drifting near surface traps

Particle flux in the ESTOC (European Station for Time-series in the
Ocean, Canary Islands) region is subject to seasonal and short-term
variability due to varying productivity and hydrographic conditions.
Experiments with moored particle traps at the ESTOC station show that a
large portion of deep particle flux originates laterally. Thus it is
important to determine particulate carbon flux directly below the
euphotic zone. Ideally, these sinking flux determinations need to be
coupled with measurements of the standing stock and production rates of
the plankton community in the euphotic zone.

To study particle flux below the euphotic zone, two types of
surface-tethered particle interceptor traps (PIT) were deployed in 200
and 220 m (Fig. 6) during two mooring periods, one beginning on 29.Dec.
1996 and ending 1. Jan. 1997 and the second one starting on 1. Jan. 1997
and ending on 4. Jan. 1997. The first array was deployed northeast of
the ESTOC station and drifted 26.7 km south-west at 20.7 cm/s, the
second one was deployed at the recovery position and continued 32.8 km
on the south-west course at 22.2 cm/s (see Tab. 1). The traps were
attached to a surface spar buoy with an ARGOS transmitter, flash and a
Radar reflector. The main buoyancy was located at about 30 m depth to
minimize the influence of the wind-driven EKMAN layer. Several positions
per day were obtained for the traps using the CLS ARGOS location service
in Toulouse/France.

To quantify the plankton community in the euphotic zone during the trap
deployments, samples were taken for chlorophyll, taxonomically
characteristic pigments (analysed with High Pressure Liquid
Chromatography, HPLC)and POC (Particulate organic carbon). All of the
water samples were filtered on GF/F filters. While chlorophyll
[a]{.underline} was analysed onboard ship as an acetone extract using a
Turner AU 10 fluorometer (supplied by the group of O. Llinas, ICCM
Telde), POC and HPLC samples were kept frozen until analysis onshore.

During the deployment of the particle trap, I conducted 3 dilution
experiments to determine phytoplankton growth and microzooplankton
grazing rates onboard close to in-situ conditions. Dilution experiments
were carried out mostly with water from 25 m and 50 m depth collected at
the beginning of the deployment period of the particle trap. The
incubations were carrried out in an on-deck incubator with neutral
density screens to simulate in-situ light conditions.

## 

# Tab. 1: Inventory of GeoB activities during M37/2a, 28 Dec 1996 - 05 Jan 1997, Canary Islands

<table>
<colgroup>
<col style="width: 6%" />
<col style="width: 4%" />
<col style="width: 6%" />
<col style="width: 8%" />
<col style="width: 7%" />
<col style="width: 7%" />
<col style="width: 10%" />
<col style="width: 9%" />
<col style="width: 10%" />
<col style="width: 10%" />
<col style="width: 8%" />
<col style="width: 8%" />
</colgroup>
<tbody>
<tr class="odd">
<td>Date</td>
<td>Stat</td>
<td>GeoB</td>
<td><p>Lat N</p>
<p>Long W</p></td>
<td>Depth m</td>
<td><p>Start time</p>
<p>UTC</p></td>
<td><p>Chl</p>
<p>(depth/m)</p></td>
<td><p>HPLC</p>
<p>(depth/m)</p></td>
<td><p>POC</p>
<p>(depth/m)</p></td>
<td><p>Dil-Exp</p>
<p>(depth/m)</p></td>
<td>Mooring</td>
<td><p>Drifting</p>
<p>Trap</p></td>
</tr>
<tr class="even">
<td>29.12</td>
<td>457</td>
<td>4245</td>
<td>29°10 15°30</td>
<td>3613</td>
<td>02:10</td>
<td><p>10,25,50,</p>
<p>75,100,150,200</p></td>
<td><p>10,25,</p>
<p>50,</p>
<p>75,100</p></td>
<td><p>10,25,50,</p>
<p>75,100,</p>
<p>150,200, 400,600,</p>
<p>800,1000,2000,3000</p></td>
<td>25,50</td>
<td></td>
<td><p>water</p>
<p>for trap</p></td>
</tr>
<tr class="odd">
<td>29.12</td>
<td>459</td>
<td>4246</td>
<td><p>29°19.8</p>
<p>15°28.3</p></td>
<td>3603</td>
<td>12:35</td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td><p>into water 200,</p>
<p>220m</p></td>
</tr>
<tr class="even">
<td>30.12</td>
<td>463</td>
<td>4247</td>
<td><p>28°44.5</p>
<p>13°18.0</p></td>
<td>1197</td>
<td>12:48</td>
<td></td>
<td></td>
<td></td>
<td></td>
<td>EBC 3</td>
<td></td>
</tr>
<tr class="odd">
<td>31.12</td>
<td>470</td>
<td>4248</td>
<td><p>28°40.0</p>
<p>12°57.0</p></td>
<td>498</td>
<td>4:45</td>
<td></td>
<td></td>
<td></td>
<td>25</td>
<td></td>
<td></td>
</tr>
<tr class="even">
<td>31.12</td>
<td>471</td>
<td>4249</td>
<td><p>28°42.5</p>
<p>13°09.3</p></td>
<td>996</td>
<td>9:11</td>
<td></td>
<td></td>
<td></td>
<td></td>
<td>EBC 2</td>
<td></td>
</tr>
<tr class="odd">
<td>01.01.</td>
<td>2</td>
<td>4250</td>
<td><p>29°05.7</p>
<p>15°31.5</p></td>
<td>3608</td>
<td>12:57</td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td>Recovery</td>
</tr>
<tr class="even">
<td>01.01.</td>
<td>3</td>
<td>4251</td>
<td><p>29°05.6</p>
<p>15°31.7</p></td>
<td>3608</td>
<td>13:03</td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td><p>into water 200,</p>
<p>220m</p></td>
</tr>
<tr class="odd">
<td>01.01.</td>
<td>4</td>
<td>4252</td>
<td><p>29°05.2</p>
<p>15°32.3</p></td>
<td>3612</td>
<td>13:42</td>
<td><p>10,25,50,</p>
<p>75,100,150,200</p></td>
<td><p>10,25,</p>
<p>50,</p>
<p>75,100,200</p></td>
<td><p>10,25,50,</p>
<p>75,100,</p>
<p>150,200</p></td>
<td></td>
<td></td>
<td></td>
</tr>
<tr class="even">
<td>02.01</td>
<td>7</td>
<td>4253</td>
<td><p>29°03.6</p>
<p>15°31.0</p></td>
<td>3608</td>
<td>14:08</td>
<td></td>
<td></td>
<td></td>
<td>25,50</td>
<td></td>
<td></td>
</tr>
<tr class="odd">
<td>03.01</td>
<td>14</td>
<td>4254</td>
<td><p>28°48.2</p>
<p>17°57.3</p></td>
<td>4327</td>
<td>9:33</td>
<td></td>
<td></td>
<td></td>
<td></td>
<td>LP 1</td>
<td></td>
</tr>
<tr class="even">
<td>04.01</td>
<td>22</td>
<td>4255</td>
<td><p>28°48.2</p>
<p>15°35.4</p></td>
<td>3586</td>
<td>18:10</td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td>Recover</td>
</tr>
<tr class="odd">
<td>04.01</td>
<td>23</td>
<td>4256</td>
<td><p>28°47.9</p>
<p>15°34.7</p></td>
<td>3585</td>
<td>18:51</td>
<td><p>10,50,</p>
<p>75,100,150</p></td>
<td><p>10,50,</p>
<p>75,100,150</p></td>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
<tr class="even">
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
</tbody>
</table>

# Particle collection with moored particle traps 

During M 37/2a, one particle trap each was attached to each of the Kiel
current meter moorings EBC 2 and EBC 3 in the Eastern Boundary Current
at 700 m depth. In addition, EBC 3 had one INFLUX current meter (group
of G. Krause, AWI) attached 20 m below the particle trap. INFLUX current
meters carry a fluorometer and a transmissometer in addition to CTD
sensors and can thus record episodic particle sedimentation events at
depth. All traps were programmed for 20x 14 days sampling intervals
starting January 6, 1997.

On January 3, mooring LP 1 was deployed as the westernmost particle trap
mooring in the CANIGO mooring line which covers the horizontal
productivity gradient from the coastal upwelling zone to the open ocean.
In this mooring line, the ESTOC mooring CI which was exchanged on M37/1
is located on about the midpoint and the particle traps in the EBC2 and
EBC3 arrays are located on the eastern end of the gradient.

Mooring LP 1 is equipped with two particle traps in 1028 m and 3780 m
and one INFLUX current meter in 1048 m depth (Table 2 ). All traps were
programmed for 20 x 14 days sampling intervals starting January 6, 1997.

# Tab. 2: Instruments used and deployment depths on mooring LP 1

Mooring Position Water Sampling Instrument Depth Intervals

depth interval (m)

LP1 29°45,73 4327 6.01.1997- RCM 5 850

13.10.1997 SMT 234 1028 20x14 days

INFLUX 1048

RCM 5 1570

SMT 230 3780 20x14 days

Instruments:

S/MT 234, Particle trap, Aquatec Meerestechnik , Kiel

S/MT 230 Particle trap, Sazgitter Electronik , Kiel

INFLUX INFLUX current meter (group G. Krause, AWI) with CTD,
fluorometer, transmissometer

RCM 5 Aanderaa current meter

### [5.3 Trace metal measurements at ESTOC, EBC and LP1]{.underline}

(A. Deeken, F. Kukolka, S. Otto)

The interaction of particles and water is a key process for the
biogeochemical cycling of chemical elements in the ocean. Uptake onto
particulate matter and subsequent sinking mechanisms (scavenging) is the
major control on the chemical composition of seawater and maintains the
concentrations of many elements in seawater rather low. The particulate
matter itself consists of (i) suspended particulate matter (SPM) which
is supposed to consist of almost non-sinkable biogenic and terrestrial
detritus with a large surface area and (ii) the relative fast sinking
particles found in sediment traps, responsible for the vertical
transport to the sediments. The comparison of the trace element
composition and distribution in these three different phases (dissolved,
SPM and particulate trap material) are excepted to provide important
clues on transport and sorption mechanisms as well as on the general
geochemical behavior of these elements in the ocean.

Our task during this cruise was to examine the vertical distribution of
trace metals in dissolved and suspended form in the water column. For
this purpose, we investigated three different mooring locations,
reaching from the eutrophic coast-near region off Africa towards the
more oligotrophic open ocean. Samples of dissolved trace metals and
suspended particulate matter were collected from the entire water column
by means of GoFlo bottles and *in situ* filtration using special *in
situ* pumps. Bottle casts combined with *in situ* SPM collections were
performed at station EBC 3 (east of the islands Lanzarote and
Fuerteventura), at the ESTOC station and at station LP (north of La
Palma). The positions occupied were sampled with a high vertical
resolution (sixteen to twenty-nine sampling depths). All samples were
collected rigorously applying clean sampling techniques to avoid
contamination as far as possible. GoFlo bottles and *in situ* pumps were
attached to a non-metallic wire and sample processing was done inside a
clean bench. Dissolved trace element samples were pressure-filtered with
nitrogen gas through pre-cleaned 0.4 µm polycarbonate membranes directly
from the sampling bottles, whereas SPM was sampled onto filters of
identical material.

Due to technical problems with the new generation of *in situ* pumps
used, sampling of SPM was reduced at all positions. At the ESTOC
station, SPM samples from nine depths, at EBC 3 six samples and at LP
two SPM samples were obtained.

Besides trace metal sampling, water samples were analyzed for nutrients
as well as for oxygen. The nutrients nitrate, phosphate and silicate
were determined according to standard photometric procedures. Oxygen was
analyzed through titration using the Winkler method. The only trace
metal to be determined onboard was total dissolvable Aluminium by a
fluorescence method. All other dissolved trace metals will be analyzed
onshore, as well as the filters from the *in situ* pumps.

### 

### [5.4 Foraminifera]{.underline}

#### Net Sampling for Planktic Foraminifera

(S. Kemle-von Mücke)

Plankton samples were collected from about 5 m water depth using the
shipboard fire pump system. The sea water was filtered through a
plankton net with a mesh size of 70 microns each day. The aim was to
collect planktic foraminifera to investigate the species assemblage and
abundance for later comparison with temperature, salinity, chlorophyll
*a* content and nutrient concentration in the surface water. Apart from
the first two samples, the planktic foraminifera were picked out from
the plankton sample and oxidized with 3,8 % NaOCl buffered with
NadiBorat to obtain clean foraminifera shells. The foraminifera were
rinsed with distilled water and 96 % ethanol and stored in fema cells.
Site locations of the sampling are listed in Table 3. The temperature
and salinity data given in the table originate from the ship
thermosalinometer.

Only very few foraminifera were found in all the samples and these
foraminifera were so small that it was often difficult to accurately
identify the species. The dominant species was *Turborotalita. humilis*
followed by *Globigerinella siphonifera*, (*Globigerinella calida*),
*Globigerinita glutinata*, *Globigerinoides ruber*. Other species found
were *Globorotalia crassaformis*, *Globorotalia inflata*, *Globigerina
bulloides,(may be Globigerina falconensis or Orbulina universa)*,
*Turborotalita quinqueloba*. By far the most common zooplankton were the
copepods. In addition, various zooplankton were present: euphausides,
pteropods, some ostracodes, radiolarian, dinoflagellates and diatoms.

**Tab. 3:** Planktic foraminifera net sampling data.

![](media/image1.emf)

##### 

##### **Collection of Planktic Foraminifera for DNA Analysis**

(K. Darling, I. Stewart)

The foraminifera were collected by pumping sea water through a 70 micron
mesh net as described in the preceding paragraph. The plankton net was
also deployed approximately four metres below the water surface for two
periods of ten minutes. Little difference was found between the two
collection methods. As the collection was made for DNA analysis, it was
not necessary to quantitatively estimate the foraminiferal assemblage
per volume of water. Pumping was therefore continuous, with serial
samples being taken at short time intervals to maximise the viability of
the living cells and to allow time for species identification. The
sampling details are outlined in Table 4. Following selection of
individual specimens, they were crushed into 30µl of buffer to protect
the DNA from enzymatic activity. The samples were then individually
labelled and stored at -20°C.

Foraminifers were scarce in the surface waters and positive
identification of individual species proved difficult, as the
foraminifers throughout the whole of the collection period were
immature. It is therefore not possible to provide an accurate species
list at this stage. We found *Turborotalita humilis*, *Globigerinella
siphonifera* (which possibly includes Type I and Type II forms of *G.
siphonifera* and *G. calida*), *Globigerinita glutinata*,
*Globigerinoides ruber* (pink and white forms). In addition we found
five specimens of *Neogloboquadrina* (intergrade) and single specimens
of *Globigerinoides sacculifer* and *Globorotalia truncatulinoides*.
Other species found were possibly *Globigerina bulloides / Globigerina
falconensis* and *Orbulina universa*. DNA analysis will provide a more
accurate species list when sequence alignment can be made against known
species within the DNA database. A total of 123 individual specimens
were taken for analysis.

**Table 4.** Sampling data for the collection of planktic foraminifers
for DNA analysis.

<table>
<colgroup>
<col style="width: 9%" />
<col style="width: 10%" />
<col style="width: 7%" />
<col style="width: 9%" />
<col style="width: 9%" />
<col style="width: 7%" />
<col style="width: 9%" />
<col style="width: 9%" />
<col style="width: 9%" />
<col style="width: 7%" />
<col style="width: 10%" />
</colgroup>
<tbody>
<tr class="odd">
<td>Sample day</td>
<td>Date</td>
<td>Pump start time</td>
<td>Position</td>
<td>Salinity °/oo</td>
<td>Temp. °C</td>
<td>Pump stop time</td>
<td>Position</td>
<td>Salinity °/oo</td>
<td>Temp. °C</td>
<td>Litres pumped</td>
</tr>
<tr class="even">
<td>1</td>
<td>29.12.96</td>
<td>13.00</td>
<td>29°20N/15°28W</td>
<td>36.83</td>
<td>19.9</td>
<td>15.00</td>
<td>29°20N/ 15°28W</td>
<td>36.84</td>
<td>20.0</td>
<td>1400</td>
</tr>
<tr class="odd">
<td>2</td>
<td>30.12.96</td>
<td>11.30</td>
<td>28°45N/13°22W</td>
<td>36.74</td>
<td>19.5</td>
<td>15.30</td>
<td>28°45N/ 13°19W</td>
<td>36.74</td>
<td>19.4</td>
<td>2800</td>
</tr>
<tr class="even">
<td>3</td>
<td>31.12.96</td>
<td>11.00</td>
<td>28°41N/13°09W</td>
<td>36.77</td>
<td>19.2</td>
<td>12.30</td>
<td>28°41N/ 13°09W</td>
<td>36.76</td>
<td>19.2</td>
<td>1050</td>
</tr>
<tr class="odd">
<td>4</td>
<td>1.1.97</td>
<td>12.00</td>
<td>29°05N/15°32W</td>
<td>36.76</td>
<td>19.7</td>
<td>16.00</td>
<td>29°05N/ 15°32W</td>
<td>36.84</td>
<td>19.7</td>
<td>4800</td>
</tr>
<tr class="even">
<td>5</td>
<td>2.1.97</td>
<td>11.00</td>
<td>29°31N/17°02W</td>
<td>36.80</td>
<td>19.8</td>
<td>16.00</td>
<td>29°37N/ 17°27W</td>
<td>36.87</td>
<td>19.8</td>
<td>7000</td>
</tr>
<tr class="odd">
<td>6</td>
<td>3.1.97</td>
<td>10.45</td>
<td>29°45N/17°57W</td>
<td>36.84</td>
<td>19.7</td>
<td>18.30</td>
<td>29°44N/ 17°58W</td>
<td>36.80</td>
<td>19.7</td>
<td>9300</td>
</tr>
<tr class="even">
<td>7</td>
<td>4.1.97</td>
<td>11.15</td>
<td>29°09N/15°40W</td>
<td>36.75</td>
<td>19.7</td>
<td>18.00</td>
<td><p>28°47N/</p>
<p>15°34W</p></td>
<td>36.75</td>
<td>19.5</td>
<td>8100</td>
</tr>
</tbody>
</table>

### [5.5 Bio-optical measurements on the CANIGO box]{.underline}

(Hans Barth, Klaus Loquay, Oliver Zielinski)

#### Introduction

The main element in the flow of dissolved and particulate organic matter
and of living organisms is carbon. Calculations which include only
chemical and physical properties of the ocean for the exchange of carbon
lead to wrong predictions. Only the inclusion of biological activities
can fill this gap in understanding the carbon cycle. In January and
February the hydrographic conditions of the Canary Island region are
characterised by coastal upwelling of intermediate water to the surface
and by an increase in phytoplankton growth. One of the main objectives
is to study the carbon assimilation and transport mechanisms by
biological activities to understand and quantify the amount of carbon
which is transported to deep waters by mixing and sinking.

Dissolved and particulate substances in seawater can be sensitively
characterised by optical methods. The method is very fast since it does
need any preparation of samples. *Gelbstoff* as a major compound of
marine DOM, chlorophyll *a* and other phytoplankton pigments like
phycoerythrin, fucoxanthin and fucocyanin, and the aromatic amino acid
tryptophan can be measured with fluorescence methods. The attenuation
coefficient is an optical parameter which depends sensitively on
suspended and dissolved substances. Its measurement is of interest not
only for the understanding of optical conditions in water, but it also
allows for a fast determination of absorbing and scattering matter in
the form of depth profiles, which can hardly be obtained with other
methods in realtime.

Optical parameters have met the interest of oceanographers and
limnologists for a long time. Devices which measure optical data are
utilised to classify water masses on the basis of optical properties and
to obtain information on particulate matter or dissolved organic
substances. The most prominent instruments of that kind used in the
present study are the following:

  ----------------------------------- -----------------------------------
  Laboratory Instruments:             In situ Instruments:

  Spectrofluorometer                  Multi Channel Fluorometer

  Spectrophotometer                   Polychromatic Transmissometer

                                      Radiometer
  ----------------------------------- -----------------------------------

For hydrographic parameters a CTD is added to the in situ probes. All of
these instruments are connected by a central underwater unit to obtain
simultaneous data sets from the water column (down to 3000m).

##### **Methods**

The following instruments were used throughout the campaign (Fig. 7, 8):

###### Spectrophotometer:

####### Type: Perkin Elmer, Lambda-18

Measurements: Absorption of filtrated (Whatman GF/F) and unfiltrated
samples in the range from 189.6 to 700 nm. Yellow substance
concentration can be derived by interpretation of the spectra.

###### Spectrofluorometer:

Type: Perkin Elmer, LS-50

Measurements: Five different excitation scans were used

+-----+---------------+----------------+------------------------------+
| S   | Excitation    | Ramanpeak      | detected substance with      |
| can |               | \[nm\]         |                              |
|     | wavelength    |                | relevant wavelength \[nm\]   |
|     | \[nm\]        |                |                              |
+-----+---------------+----------------+------------------------------+
| A   | 530           | 646.5          | Chlorophyll *a* at 680 nm    |
+-----+---------------+----------------+------------------------------+
| B   | 420           | 490.0          | Chlorophyll *a* at 680 nm    |
+-----+---------------+----------------+------------------------------+
| H   | 308           | 344.0          | Tryptophan at 340 nm         |
|     |               |                |                              |
|     |               |                | Gelbstoff at 420 nm          |
+-----+---------------+----------------+------------------------------+
| J   | 270           | 397.3          | Tryptophan at 340 nm         |
|     |               |                |                              |
|     |               |                | Gelbstoff at 440 nm          |
+-----+---------------+----------------+------------------------------+
| N   | 230           | 249.5          | Tyrosine at 300 nm           |
|     |               |                |                              |
|     |               |                | Tryptophan at 340 nm         |
|     |               |                |                              |
|     |               |                | Gelbstoff at 420 nm          |
+-----+---------------+----------------+------------------------------+

###### Multi Channel Fluorometer:

####### Type: Prototype

Measurements: Using two excitation wavelengths (270 nm and 420 nm) from
a Xe-flashlamp spectrum via optical filters, the following substances
are detected:

Raman at 397.3 nm and 490.0 nm, Chlorophyll, yellow substance,
Tryptophan, Phycoerythrin and Fucoxanthin.

###### Polychromatic Transmissometer:

####### Type: Prototype

Measurements: Attenuation coefficient in the range of 370 nm to 730 nm
at 134 wavelengths. The optical pathlength is adjustable to different
turbidity situations.

###### Radiometer:

####### Type: Prototype

Measurements: Underwater light field (vectorial irradiance), upwelling
and downwelling in the range of 370 nm to 730 nm at 67 wavelengths.

######## CTD:

####### Type: Meerestechnik Elektronik, OTS 1500

Measurements: Pressure, conductivity and temperature. Calculated
components include salinity and sound speed.

#### Data sampling

Water samples from the Niskin Sampler were taken (if available) at every
station from the CTD/rosette following this scheme: 10m, 25m, 50m, 75m,
100m, 125m, 300m, 1000m, 1250m, 1500m depth and 20m above seafloor. The
optical sensors were used at every station down to a depth of 1500m.
Station 38 was probed down to 2070m, station 63 where the Meddy 'Jani'
was observed (Fig. 9) down to 1800m. Underwater light field measurements
were carried out only at daytime starting with station 56.

.

### [5.6 Measurements of Al and other trace metals on the CANIGO box]{.underline}

(M.D. Gelado-Caballero, F.J. Martin- Muñoz and J.J.Hernández-Brito)

#### Introduction

Aluminium distributions in Canary Islands (Central East Atlantic Waters)
show a great variability \[Gelado-Caballero et al. , 1996\]. The area
possesses major features that could affect the aluminium biogeochemical
behaviour, such as elevated aeolian (dust) inputs from the Sahara
desert, proximity to areas of upwelling (150-200 Km) and mesoscale
features induced by the effect islands on the course of the Canary
Current. The aluminium distributions show a marked latitudinal gradient
from East to West. The study of the Al variations along these gradients
and at a fixed station could give a better knowledge of the physical and
biogeochemical processes controlling mesoescale distribution of
aluminium in the area.

### Al determinations

The HPACSV (High Performance Adsorptive Cathodic Stripping Voltametry)
method (Hernández-Brito et al., 1994a) was used to measure on board
dissolved aluminium in seawater. Samples are prepared in Teflon cups of
polarographic cell, containing 10 ml of water, 2·10-6 M DASA and 0.01 M
BES. The solution is purged using nitrogen (3 minutes) to remove
dissolved oxygen. The adsorption potential (-0.9 V) is applied to the
working electrode, while the solution is stirred. After 40s accumulation
time, the stirring is stopped and 5 s is allowed for the solution to
became quiescent. The scanning is started at -0.9 V and terminated at
-1.4 V. The scan is made using staircase modulation with a scan rate of
30 V/s and a pulse height of 5 mV. The DASA-Al peak appears at ca. -1.25
V. A standard addition procedure is used to quantify the aluminium
concentration of the sample. Determinations were carried out in a flow
bench class-100 to avoid contamination of the sample by dust particles.

The electrochemical system used has been designed to measure the
instantaneous currents at short times with a low noise level
(Hernandez-Brito et al., 1994b). Thus, the analytical time required for
each sample is substantially reduced, allowing an increase of
measurements on board. A PAR- 303A electrochemical cell with hanging
mercury drop electrode (HMDE) was connected to a specially made
computer-controlled potentiostat.

The reproducibility of the method was less than 4% for a 21 nM Al
concentration based on seven replicates sampled at 2000 m (28°25.40´ N
15° 24.70´W). A detection limit of 2.5 nM was calculated using these
results.

The water sampling was carried out using Niskin bottles provided with
silicone rubber and stain steel springs. Replicated samples taken at the
same depth showed no significant contamination from the springs (less
than 4%). The possible contamination by the rosette frame was tested by
comparison with seawater sampled using a rubber boat. Aluminium values
using both devices showed differences within the experimental error
(4%). Samples were taken and manipulated wearing plastic gloves to avoid
contamination. Additional samples were frozen at polyethylene bottles to
carry out analysis at the land-based laboratory. Every container has
been previously cleaned using conventional procedures in the trace metal
assay.

**Preliminary results**

More than 500 samples were analysed on board. Preliminary results shows
that aluminium distribution in the water columns appears to be related
with the physical and biogeochemical processes in the area sampled.
Aluminium distribution in the surface waters shows a winter mixed
surface layer without the maximum concentrations found during previous
cruises at summer and fall at the area. Mid-depth aluminium
distributions seem to be related to the water masses. Low Al values have
been found (800 m) in the channel between Lanzarote and the African
continental slope. Low salinity waters have been measured at the same
depth. Stations located west of Lanzarote show higher aluminium
concentrations and no salinity minimum at this deepness. An aluminium
maximum appears at intermediate waters (1000-1300 m) and it seems to be
related with the intrusion of Mediterranean waters. A minimum in the
aluminium distributions occurs below the Mediterranean waters. The
aluminium concentrations increase again below 2500m. Stations close to
the continental slope show higher aluminium near the bottom layer. It
could be an indication of sediment dissolution or lateral transport of
sediment at the deep layers. The profiles in the western most stations
show no significant alterations near the bottom.

**[5.7 Measurements of CO2 on the CANIGO box]{.underline}**

(L. Mintrop, M. Gonzalez-Davila, F.F. Perez)

A total of 351 samples were drawn and immediately analyzed for total
dissolved inorganic carbon (C~T~). 18 further samples were drawn from 6
sample bottles (3 each), which had been closed at 3 different depth (
10, 3799, 1100m ) at stations 59, 62, 64, and 65. These samples served
for an alkalinity intercalibration between the 3 different CO~2~ -
workgroups and were measured after the cruise. The analytical methods
involved are a coulometric titration technique for C~T~ (SOMMA-system,
Johnson et al*.*, 1994; DOE, 1994) and potentiometric titration for
A~T~, basically according to Millero et al*.* (1993), but carried out in
an open vessel (VINDTA-system, Mintrop, 1996, unpubl.). Alkalinity was
calculated from the titration curve by a curve fitting procedure
(Millero and Campbell, 1994). The coulometric system was calibrated with
pure CO~2~ (gas calibration) and tested by running different batches of
certified reference material (CRM, provided by A. Dickson, SIO, La
Jolla, CA, U.S.A.). The same CRMs were also used to monitor alkalinity
titrations. For the VINDTA system, the pipette volume was determined by
filling with distilled water and weighting, the acid used was prepared
in a batch, and the acid factor of the batch was determined
coulometrically (A. Dickson, pers. comm.). The precision (between-bottle
reproducibility) as judged from regular measurements of duplicate
samples was 0.5 µmol.kg^-1^ for C~T~ and 0.5 µmol.kg^-1^ for A~T~.
Accuracy of the data has been estimated to be about 1.5 µmol.kg^-1^ for
C~T~ and 2.0 µmol.kg^-1^ for A~T~.

The alkalinity intercomparison gave a very close agreement of the
results for the three groups involved within the precision of the method
(within ± 1 µmol.kg^-1^ ) thus allowing perfect data exchange within the
groups for the future. The determination of dissolved inorganic carbon
gave distinct differences in the depth distribution for the northern and
southern zonal transects. We hope to be able to calculate carbon
transport with the help of hydrogaphical data and estimates for water
transport rates resulting from the investigations of the physical
oceanography work groups. Figure 10 shows an isoplot along the southern
transect towards east, the meridional transect northbound and the zonal
continuation along the northern transect back to the African coast.
Outstanding feature is the maximum at 1000-1500m depth, indicating the
Mediterranean outflow; higher values at depth in the southern transect
in comparison to the northern transect indicate the prevalence of
southern component water here.

### [5.8 Measurements of DOC on the CANIGO box]{.underline}

(G. Fengler)

#### Introduction

Dissolved organic carbon (DOC) in the ocean contain a total mass of
carbon comparable to that in the atmosphere (Hedges, 1992). Consequently
small changes in the cycling of DOC have a potentially large impact on
the global carbon cycle. Despite this importance, DOC still continues to
be the least understood pool of carbon. Many recent studies have
addressed the question of the nature of DOC and the problems involved in
its measurements (e.g. Sugimura & Suzuki, 1988; Suzuki 1993; Hedges &
Lee, 1993; Sharp, 1993; Cauwet, 1994).

The objective of this study is, to determine the spatial distribution of
DOC within the research area.

#### 

#### 

#### Methods

Ultra-clean sampling and filtration techniques were employed on samples
recovered from CTD-Hydro-casts (see 7.1). DOC is operationally defined
here as all organic carbon passing a glass fibre filter (GF/F, Whatman
precombusted at 4500 C for 5h). Quantitative analyses of DOC will be
performed within the laboratories of the Institute of Biogeochemistry
and Marine Chemistry at the University of Hamburg by using the
high-temperature oxidation (HTCO) method in which a home-made
DOC-analyser will be used. After carbonate removal by acidification to a
pH of 2 with 50% H3PO4 and subsequent purging (10 min with CO2 free
oxygen), 100 µl samples will be injected directly onto the pure platinum
catalyst (Ionics, Inc.) and oxidise at 8000 C. The effluent from the
furnace passes through a water separator, a mossy tintrap to remove HCl
gas, through a cold trap at 10 C, a MgClO4 trap, a particle filter
(Balston Type 9900-05-BK DFU) and finally into an IR analyser (Licor
6252). Oxygen will be used as the carrier gas at 130 ml/min. Peak areas
will be determined with an Hewlett Packard 3396A integrator. The
calibration of the DOC-Analyser will be done with a series of potassium
hydrogenophtalate standard solutions.

**[5.9 Measurements of cocolithophores and diatomes on the CANIGO
box]{.underline}**

#### Coccolithophores

(J. Bollmann)

Coccolithophore sampling during cruise M37/2B is part of CANIGO
Subproject 3. The scientific goals are (a) to obtain a better
understanding of the seasonal and interannual interaction between
coccolithophores and the physical environment and (b) to compare this
interaction with the long-term variability of coccolith composition and
flux into the sedimentary archives.

During cruise M37/2b, water casts of 10 litres were taken at 23 stations
and the following water depth levels were sampled: 0, 10, 25, 50, 75,
100, 125, 150, 200, 250, 300 meters. 13 stations were sampled along a
zonal transect from the African coast to La Palma, 2 stations were
sampled during the meridional transect from La Palma to Madeira and 8
stations during the zonal transect from Madeira towards the African
coast (Fig.. 1, see also 7.1).

Carboys were rinsed twice (about 0.5 litres) with tap water and up to 8
litres of water were transferred from the Niskin bottles for each depth
level into carboys. Within one hour the water was filtered onboard
through Nucleopore PC filters (0.8µm, 47 mm diameter) using a low-vacuum
filteration device. Filtration was terminated if the filter became
clogged up and the amount of remaining water was measured and noted.
After filtration the filters were rinsed with 50ml of distilled water to
eliminate all traces of sea salt, to which 1-2 drops of NH4OH per litre
were added to obtain a pH of about 8.5 to prevent carbonate dissolution.
Rinsed filters were transferred to labelled petri-dishes, dried
immediately in an oven at 55 ° and stored in a refrigerator.

In subsequent analyses using a Scanning Electron Microscope cell density
(#/l) and taxonomic composition of the coccolithophore populations will
be determined. In addition morphological features of *Gephyrocapsa* sp.
and *Calcidiscus leptoporus* will be analysed.

#### 

#### Diatoms

(J. Bollmann, Antonio Correira)

Diatom sampling during cruise M37/2b is part of the CANIGO Subproject 3.

The scientific goals are (a) to determine diatom standing stock and
assemblage compostion at distinct water depth levels and (b) to
construct transfer functions between diatom abundances and assemblages
and environmental parameters and (c) to compare the results of these
analyses with long-term variability of diatom compositions in sediments
and diatom flux into the sedimentary archives.

During cruise M37/2b water casts of 10 litres were taken at 11 stations
along a zonal transect from the African coast to La Palma and the
following water depth levels were sampled: 0, 10, 25, 50, 75, 100, 125,
150, 200, 250, 300 meters. 200 ml water were transfered from Niskin
bottles into plastic bottles and Formol and Hexamethyl-Tetramine was
added.

At 25 stations a plankton net with 63 µm mesh size was used to sample
diatoms within the upper 100 m water column (intergrated sampling). The
net was released to 100m water depth and was pulled with 0.3 m/s back to
the surface. Subsequently the net was rinsed with sea water and the
catch was tranfered into a plastic bottle and Glutardialdehyde was
added.

In subsequent analyses using a light microscope and if necessary a
Scanning Electron Microscope, diatom standing stock and assemblage
composition will be determined.

### [5.10 Zooplankton as tracers in intermediate waters off Morocco at 29°N and 32°N]{.underline}

(H.-Ch. John, C. Zelck)

#### Purpose

It is intended to analyse the intermediate meridional plankton
transports along the Moroccan continental slope. It is presumed that
some tropical planktonic species reach Morocco by means of a narrow
poleward undercurrent located at about 400 to 800 m depth, whilst other,
more northern species drift southwards in a zonally broader band
influenced by the Mediterranean Outflow Water (MOW), located at broadly
1000 m depth. The bottom topography of the Canary Archipelago is likely
to disturb both flows at least locally.

#### Sampling

Mesozooplankton of the 300 µm size fraction was sampled by vertical tows
with a multiple-opening-closing net (MUV). The MUV had an integrated
CTD-system with real-time data transfer to the lab. Sampling was
generally done between 1000 m and the surface, separated into 5 strata
200 m wide each, unless shallower bottom depths interfered. In these
cases narrower strata were sampled. Six additional deep stepwise tows
down to 2000 m were also made on identical positions. Details on the
tows and vertical resolution are listed in Table 5, haul positions are
listed in Section 7.1.

All stations yielded succesful tows, except that three malfunctions of
the sampler resulted in integrations of two depth strata each (Table 5).
One stratum was completely lost due to a torn net. Some of the CTD-files
show spikes, for which the reasons are still unknown, but the data can
be recovered.

The stations ran broadly zonal and cross-slope along the transects at
approoximately 29°N and 32°N, except for test station no. 1. The station
spacing was from the shelf edge across the continental slope
approximately 5-6 nautical miles (n.m.), but increased from 10 to 60
n.m. in the open ocean.

**Tab. 5:** MUV-tows obtained during leg 2 of „Meteor" cruise 37. Listed
are ship station versus haul numbers, the depth strata sampled and the
abundance of fish larvae (as far as analysed during the cruise).

Sta Haul Net 1 Net 2 Net 3 Net 4 Net 5 N Fish

\# \# (m) (m) (m) (m) (m) /1m²

26 1 1000-800 800-600 600-400 400-200 200-0 92

29 2 240-200 200-150 150-100 100-50 50-0 64

30 3 350-300 300-200 200-100 100-50 50-0 88

31 4 575-400 400-300 300-200 200-100 100-0 32

32 5 795-600 600-400 400-200 200-100 100-0 48

33 6 1000-800 800-600 600-400 - 400-0 56

34 7 1000-800 800-600 600-400 400-200 200-0 28

35 8 1000-800 800-600 600-400 400-200 200-0 60

36 9 800-600 600-400 400-200 200-100 100-0 124

37 10 985-800 800-600 600-400 400-200 200-0 60

38 11 2000-1600 1600-1400 1400-1200 1200-1000 1000-0 28

38 12 1000-800 800-600 600-400 400-200 200-0 0

39 13 1000-800 800-600 600-400 400-200 200-0 52

39 14 2000-1600 1600-1400 1400-1200 1200-1000 1000-0

40 15 1000-800 800-600 600-400 400-200 200-0

42 16 1000-600 600-400 400-200 200-100 100-0

44 17 1000-800 800-600 600-400 400-200 200-0

46 18 1000-800 800-600 600-400 400-200 200-0

49 19 1000-800 800-600 600-400 - 400-0

62 20 1000-800 800-600 600-400 400-200 200-0

62 21 2000-1600 1600-1400 1400-1200 1200-1000 1000-0

63 22 1000-800 800-600 600-400 400-200 200-0

64 23 1000-800 800-600 600-400 400-200 200-0

65 24 1000-800 800-600 600-400 400-200 200-0

##### 65 25 2000-1600 1600-1400 1400-1200 1200-1000 1000-0 

66 26 1000-800 800-600 600-400 400-200 200-0

##### 66 27 2000-1600 1600-1400 1400-1200 1200-1000 1000-0 

67 28 1000-800 800-600 600-400 400-200 200-0

##### 67 29 2000-1600 1600-1400 1400-1200 1200-1000 1000-0 

68 30 1000-800 800-600 600-400 400-200 200-0

69 31 1000-800 800-600 600-400 400-200 200-0

70 32 500-400 400-300 300-200 200-100 100-0

#### 

#### 

#### Results

On board, only the first 12 hauls could be coarsely analysed. The fish
larvae abundances (included in Table 5) are perhaps slight
underestimates due to both, the quick check and the ical tows. The
material is generally in excellent conditions.

##### 

##### *Ichthyology*

We obtained a developmental series from early larvae to transforming
specimens of lanternfish Lobianchia dofleini. Such series are known to
science and are adequately described, but larvae of this species have
previously not been caught by us and were missing from the collections
of „Zoologisches Museum Hamburg".

We identified a transforming specimen of deep-sea smelt Bathylagus
greyae. The larval development of B. greyae was previously unknown,
contrary to most other Atlantic bathylagids. We caught also two early
bathylagid larvae. These lacked meristic features for identification,
but they showed a similar basic pigment pattern as the transforming B.
greyae, and they definitely not belonged to any of the known species.

We caught in one of the deep hauls a transforming larva of the
bathypelagic family Searsiidae. The specimen is by meristic characters
and postopercular pores with a high degree of certainty referable to
Normichthys operosus. The ontogeny of Searsiidae seems to be completely
unknown in spite of being a large family with 31 species.

The remaining fish species are well known to us. The ichthyocoenosis
appears to have by diversity and some indicator species (Vinciguerria
nimbaria, Engraulis encrasicolus, no Clupeidae) a warm-water character
both near-shore and offshore. Within the archipelago neritic and oceanic
species co-occurred. The highest abundances were found at the slopes
(table 1).

##### *Invertebrates*

We caught in two hauls two bathypelagic Nemertini which have to be
handed to experts. They appear to us laymen remarkable in that one seems
to deviate from normal organisation by a dorsal insertion of the lateral
nerves. The other, less transparent one is an egg-bearing female folding
its sides ventrally to form a „marsupium" and shoowing „leg-like"
appendages in front and behind the marsupium.

The upwelling-systems copepod Calanoides carinatus was almost absent
from the samples. Only two specimens were so far found within the Canary
Archipelago.

##### *Meridional plankton drift*

Potential indicators for the poleward intermediate undercurrent were
found only within the archipelago itself, but not at the Moroccan slope.
The flow there may have been weak or non-existent during the warm
conditions. The tropical mesopelagic fish Cyclothone livida seems to be
frequent and to coincide in depth with a poleward flow passing through
the archipelago. It needs further analysis to establish its offshore
boundaries.

No species indicating the MOW (Cyclothone pygmaea, Ceratoscopelus
maderensis) have so far been found, but the majority of deep tows has
yet to be analysed.

**[6. Ship's Meteorological Station]{.underline}**

#### Cruise, course and weather

At 16:00 UTC of December 28^th^, 1996 METEOR cruised out of Las Palmas.
Being north of the Canary Islands we were situated at the edge of a low
west of Portugal. There we mostly had moderate westerly winds, only when
we were passed by cold fronts we experienced Bft 6 to 7 with
showersqualls, even a few thunderthorms were observed.

After the interruption of the cruise at Las Palmas at January 5^th^ and
6^th^, 1997 a low moved eastwards far north of the Canary Islands. Thus,
there were some showers but only southwesterly winds Bft 4 to 5. Lateron
we were infuenced by a high pressure cell with only light to moderate
winds. From January 12^th^ to 14^th^ an intense low was situated in the
area of Madeira. Being north of La Palma we had some spells with Bft 8
and heavy showers and thunderstorms. While cruising the hydrographic box
the low was filling on our way to Madeira and the windspeed decreased.
From January 15^th^ to 18^th^ we were steaming eastwards at roughly
32øN. At those days we were situated north of a high with southwesterly
winds Bft 4 to 5. At the last days of the cruise near the Moroccan coast
we were influenced by a low moving from the Biscay towards the Canary
Islands. Thus, we experienced some periods with Bft 6 and heavy showers.
In the morning hours of January 22th METEOR reached Las Palmas again.

#### Activities of the ship's weather watch

Two written weather reports were generated daily for the scientific and
nautical crew. These reports were explained verbally in greater detail.
Except for some observations from the ship's weather station, the basis
for the forecasts were synoptic weather charts which were produced twice
a day using the 6:00 and 12:00 UTC meteorological observations from
islands and ships of the northern Atlantic and land stations of western
Europe. Additionnally, forecast charts of the DWD (Deutscher
Wetterdienst), the ECMF (European Centre of Middle Range Weather
Forecasts) and the English weather service in Bracknell were used. Eight
weather observations per day were generated, six of them with cloud and
sea observations. These were transferred into the international
observation network via the DCP (Data Collecting Platform). At last,
many meteorological parameters (wind direction and speed, moisture,
precipitation rates, radiation, temperature of air and water) were
continually measured and recorded.

**[7. Lists]{.underline}**

**7.1** METEOR cruise 37/2 station and sample log

Status: 30 Oct 1997

**Last changes:**

Station 68, profile 93, positon to 32 04.850, 010 05.868

CFCs sampled at station 7, profile 11

**List of abbreviations:**

St : Station no.

Pr : CTD profile no., monotonically increasing during the cruise

Wd : Waterdepth

Instr : Type of instrumentation or mooring or equipment

NBX : Neil Brown CTD probe no X with 21x10 l bottle rosette

RXXX : RAFOS float no. XXX

VXXX : Mooring no XXX

DTRAP: Drifting sediment traps

TRACE: Cast for trace elements with GoFlo bottles and in-situ

pumps on Kevlaer rope

XBTJJ : XBT type T7, profile no JJ

**Parameter list for CTD/rosette:**

1 Ctd with optic sensors ahead or after CTD/rosette

2 lowered ADCP (LADCP) on CTD/rosette

3 rosette

4 oxygen

5 carbon dioxide system components

6 dissolved organic carbon (DOC)

7 aluminium

8 nutrients

9 chlorophyll

10 salt

11 optics

12 coccolitho\...

13 plankton samples from rosette

14 plankton net after or ahead of CTD/rosette

15 multiple closing net after or ahead of CTD/rosette

From stations 456 to 473, 1 to 4 and 66 to 72, a fluorometer was
attached to the CTD.

Parameter no

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

Date Time St Pr Latitude Longitude Wd Inst 1 2 3 4 5 6 7 8 9 10 11 12 13
14 15

UTC UTC North West 0 not sampled

MMDD hhmm GG MM.MM GG MM.MM \[m\] 1 sampled

1996/97

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

1228 1624 Sail from Las Palmas, begin of M37/2

1228 2025 456 1 28 25.40 15 24.70 3350 NB2 Test acoustic release

1229 0215 457 2 29 10.00 15 30.00 3600 NB2

1229 1045 458 3 29 14.50 15 27.90 3600 TRACE

1229 1236 469 -9 29 19.8 15 28.3 3603 DTRAP Drifting sediment trap
deployed

1229 1406 460 -9 29 19.3 15 27.3 3605 TRACE

1230 0744 461 -9 28 48.39 13 38.83 1044 VEBC5 CANIGO mooring EBC5
deployed

1230 0755 462 4 28 48.30 13 39.30 1030 NB2

1230 1049 463 -9 28 46.39 13 28.02 1281 VEBC4 CANIGO mooring EBC4
deployed

1230 1406 464 -9 28 44.49 13 17.96 1180 V3771 CANIGO mooring EBC3/377100
deployed

1230 1523 465 -9 28 45.0 13 19.8 1276 TRACE

1230 1925 466 5 28 46.50 13 29.10 1280 NB2

1230 2129 467 -9 28 46.3 13 29.0 1279 TRACE

1231 0015 468 6 28 44.90 13 19.80 1240 NB2

1231 0230 469 7 28 41.90 13 06.00 850 NB2

1231 0455 470 8 28 40.00 12 57.00 500 NB2

1231 0735 471 -9 28 39.89 12 56.83 490 VEBC1 CANIGO mooring EBC1
deployed

1231 1045 472 -9 28 42.49 13 09.34 996 V3781 CANIGO mooring EBC2/378100
deployed

1231 1134 473 -9 28 44.4 13 15.6 1138 TRACE

0101 0800 1 -9 29 09.7 15 30.1 3609 TRACE

0101 1000 1 9 29 09.40 15 30.17 3608 NB2

0101 1230 2 -9 29 06.4 15 31.5 3608 DTRAP Drifting sediment trap
recovered

0101 1323 3 -9 29 05.57 15 31.67 3609 DTRAP Drifting sediment trap
deployed

0101 1345 4 10 29 05.20 15 32.30 3610 NB2

0101 1606 5 -9 29 09.75 15 40.15 3624 V3672 ESTOC mooring V367200
recovered

0101 2015 6 -9 29 10.0 15 30.1 3608 TRACE

0101 2257 7 11 29 03.50 15 31.00 3600 NB2 ESTOC: CFCs sampled from
rosette

0102 0325 8 -9 29 10.00 15 30.00 3600 TRACE

0102 1910 9 12 29 45.00 17 59.90 4350 NB2 Test acoustic release

0102 2059 10 -9 29 45.9 18 02.9 4366 TRACE

0102 2319 11 13 29 45.00 17 59.90 4355 NB2

0103 0306 12 -9 29 46.0 18 03.0 4366 TRACE

0103 0635 13 14 29 48.00 18 11.50 4403 NB2

0103 1202 14 -9 29 45.73 17 57.26 4327 VLP1 CANIGO mooring LP1 deployed

0103 1247 15 -9 29 45.9 18 03.0 4365 TRACE

0103 2100 16 15 29 37.56 17 29.81 4201 NB2

0104 0110 17 16 29 29.99 16 55.97 3800 NB2

0104 0553 18 17 29 20.96 16 23.93 3704 NB2

0104 0803 19 18 29 15.05 15 59.95 3633 NB2

0104 1435 20 -9 29 9.0 15 40.0 3616 V3673 ESTOC mooring V376300 deployed

0104 1455 21 19 29 9.08 15 40.95 3617 NB2

0104 1810 22 -9 28 48.2 15 35.4 3586 DTRAP Drifting sediment trap
recovered

0104 1850 22 20 28 47.91 15 34.72 3586 NB2

0104 1927 22 21 28 47.76 15 34.76 3500 NB2

0104 2250 23 22 29 06.09 15 6.51 3576 NB2

0105 0235 24 23 28 58.00 14 33.00 3300 NB2

0105 0500 25 24 28 54.40 14 15.20 2962 NB2

0105 1412 Call port of Las Palmas, end of M37/2a

0106 1900 Sail from Las Palmas, begin of M37/2b

0106 2300 26 25 28 14.22 15 08.38 2716 NB2 Test Station

0107 1435 27 26 28 33.49 12 31.97 100 NB2 1 0 1 1 1 1 1 1 1 0 1 1 1 0 0

0107 1708 28 27 28 36.39 12 43.38 171 NB2 1 0 1 0 1 1 1 1 0 0 1 0 0 0 0

0107 1917 29 28 28 37.03 12 48.88 248 NB2 1 1 1 1 1 0 1 1 1 0 0 1 1 1 0

0107 2058 29 29 28 37.12 12 48.62 247 NB2 1 1 1 1 1 1 1 1 1 0 1 1 1 0 1

0107 2253 30 30 28 37.81 12 54.35 357 NB2 1 0 1 0 1 1 1 1 0 1 1 0 0 0 1

0108 0145 31 31 28 39.49 13 00.23 587 NB2 1 1 1 1 1 0 1 1 1 1 1 1 1 1 1

0108 0515 32 32 28 40.44 13 06.00 799 NB2 1 1 1 0 1 0 1 1 0 1 1 0 0 0 1

0108 0859 33 33 28 42.28 13 12.22 1059 NB2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

0108 1315 34 34 28 44.14 13 22.05 1300 NB2 1 1 1 0 1 1 1 1 0 1 1 0 0 0 1

0108 1905 35 35 28 45.96 13 33.64 1197 NB2 1 1 1 1 1 1 1 1 1 0 1 1 1 0 1

0108 2323 36 36 28 48.31 13 42.65 848 NB2 1 1 1 1 1 1 1 1 1 1 1 0 0 0 1

0109 0330 37 37 28 51.21 13 56.34 1130 NB2 1 1 1 1 1 0 1 1 1 1 1 0 0 0 1

0109 0557 37 38 28 50.97 13 56.06 1030 NB2 1 0 1 0 0 0 0 0 0 0 0 1 0 1 1

0109 0935 38 39 28 52.50 14 06.39 2100 NB2 1 1 1 1 1 1 1 1 1 1 1 0 1 0 1

0109 1325 38 40 28 52.50 14 06.22 2100 NB2 1 0 1 0 0 0 0 0 0 0 0 1 0 1 0

0109 1747 39 41 28 56.37 14 22.42 2945 NB2 1 1 1 1 0 1 1 1 1 1 1 0 0 0 1

Parameter no

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

Date Time St Pr Latitude Longitude Wd Inst 1 2 3 4 5 6 7 8 9 10 11 12 13
14 15

UTC UTC North West 0 not sampled

MMDD hhmm GG MM.MM GG MM.MM \[m\] 1 sampled

1996/97

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

0110 0155 40 42 29 01.03 14 43.93 3517 NB2 1 1 1 1 1 0 1 1 1 1 1 0 0 0 0

0110 0548 40 43 29 00.98 14 44.02 3515 NB2 1 0 1 1 1 0 1 1 1 0 0 1 0 0 1

0110 0913 41 44 29 05.71 15 06.69 3581 NB2 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0

0110 1518 42 45 29 09.97 15 29.98 3615 NB2 1 1 1 1 1 1 1 0 0 1 1 0 0 0 0

0110 1945 42 46 29 10.09 15 30.08 3615 NB2 1 0 1 0 0 0 0 0 0 0 0 1 1 0 1

0110 2300 43 47 29 10.23 15 50.07 3629 NB2 1 1 1 1 0 1 1 1 1 1 1 0 0 0 0

0111 0505 44 48 29 09.91 16 11.84 3660 NB2 1 1 1 1 0 0 1 1 1 1 1 0 0 0 0

0111 0852 44 49 29 09.10 16 12.02 3707 NB2 1 0 1 0 0 0 0 0 0 0 0 1 0 1 1

0111 1124 45 50 29 09.90 16 33.99 3707 NB2 1 1 1 1 1 0 0 1 0 1 1 0 0 0 0

0111 1531 45 51 29 09.94 16 34.00 3708 NB2 1 0 1 1 1 0 1 1 1 0 1 0 0 0 0

0111 1755 46 52 29 09.96 16 54.91 3839 NB2 1 1 1 1 0 1 1 1 0 1 1 0 0 0 0

0111 2305 46 53 29 09.88 16 54.67 3837 NB2 1 0 1 1 0 1 1 1 1 0 1 1 1 1 1

0112 0137 47 54 29 10.00 17 17.04 3916 NB2 1 1 1 1 1 0 1 1 0 1 1 0 0 0 0

0112 1026 48 55 29 09.89 17 39.13 3741 NB2 1 1 1 1 0 1 1 1 0 1 1 0 0 0 0

0112 1500 48 56 29 09.87 17 38.71 3736 NB2 1 0 1 1 0 1 1 1 1 0 1 1 0 0 0

0112 1753 49 57 29 09.94 17 59.99 3694 NB2 1 1 1 1 1 1 1 1 0 1 1 0 0 0 1

0112 2304 49 58 29 09.76 18 00.11 3693 NB2 1 0 1 1 1 1 1 1 1 0 1 1 0 1 0

0113 0318 50 59 29 47.02 17 59.90 4373 NB2 1 1 1 1 0 0 1 1 0 1 1 0 0 0 0

0113 0800 50 60 29 46.94 18 00.09 4370 NB2 1 0 1 1 0 0 1 1 1 0 1 1 1 0 0

0113 1616 51 61 30 14.91 18 00.17 4492 NB2 1 1 1 1 1 1 1 1 0 1 1 0 0 0 0

0113 2050 51 62 30 14.82 18 00.57 4492 NB2 1 0 1 1 1 1 1 1 1 0 1 0 0 0 0

0114 0024 52 63 30 44.99 17 59.98 4542 NB2 1 1 1 1 0 0 1 1 0 1 1 0 0 0 0

0114 0510 52 64 30 44.99 18 00.10 4543 NB2 1 1 1 1 0 0 1 1 1 0 1 0 0 0 0

0114 1055 53 65 31 14.95 18 00.01 4576 NB2 1 0 1 1 1 1 1 1 1 0 1 0 0 0 0

0114 1208 53 66 31 14.98 18 00.00 4574 NB2 1 1 1 1 0 1 1 1 0 1 1 0 0 0 0

0114 1529 53 -9 31 14.98 17 59.99 4573 R209 RAFOS float 209

0114 1855 54 67 31 44.98 17 59.97 4553 NB2 1 1 1 1 0 1 1 1 0 1 1 0 0 0 0

0114 2318 54 68 31 45.05 18 00.34 4553 NB2 1 0 1 1 0 1 1 1 1 1 1 0 0 0 0

0114 2347 54 -9 31 44.99 18 00.35 4553 R211 RAFOS float 211

0115 0303 55 69 32 14.96 17 59.89 4427 NB2 1 1 1 1 0 1 1 1 0 1 1 0 0 0 0

0115 0740 55 70 32 15.18 18 00.24 4426 NB2 1 1 1 1 1 1 1 1 1 0 1 1 0 1 0

0115 1124 56 71 32 15.07 17 24.89 4222 NB2 1 1 1 1 1 1 1 1 0 1 1 0 0 0 0

0115 1603 56 72 32 14.98 17 25.01 4221 NB2 1 0 1 1 1 1 1 1 1 0 1 0 0 1 0

0115 1932 57 73 32 14.98 16 49.92 3582 NB2 1 1 1 1 1 1 1 1 0 1 1 0 0 0 0

0115 2340 57 74 32 14.99 16 50.12 3570 NB2 1 0 1 1 0 1 1 1 1 0 0 0 0 1 0

0116 0309 58 75 32 14.94 16 09.95 4300 NB2 1 1 1 1 0 0 1 1 0 1 1 0 0 0 0

0116 0751 58 76 32 15.08 16 09.95 4303 NB2 1 0 1 1 0 0 1 1 1 0 1 1 0 1 0

0116 1246 59 77 32 14.92 15 09.98 4367 NB2 1 1 1 1 0 1 1 1 0 1 1 0 0 0 0

0116 1715 59 78 32 14.93 15 09.98 4368 NB2 1 0 1 1 1 1 1 1 1 0 1 0 0 0 0

0116 1752 59 78 32 14.86 15 09.97 4368 R212 RAFOS float 212

0116 2245 60 79 32 14.98 14 10.06 4336 NB2 1 1 1 1 1 0 1 1 0 1 1 0 0 0 0

0117 0309 60 80 32 14.98 14 10.15 4335 NB2 1 0 1 1 1 0 1 1 1 0 1 1 0 0 0

0117 0830 61 -9 32 16.00 13 12.40 4020 V3791 CANIGO sound source mooring

SQ4/V379100 deployed

0117 1045 62 81 32 14.88 13 09.82 3995 NB2 1 0 1 1 1 1 1 1 1 0 1 0 0 0 0

0117 1408 62 82 32 15.00 13 09.96 3998 NB2 1 1 1 1 1 1 1 0 0 1 1 0 0 1 1

0117 1848 62 -9 32 15.06 13 09.88 4000 R213 RAFOS float 213

0118 0420 63 83 32 14.94 12 09.92 3379 NB2 1 1 1 1 0 0 1 1 0 1 1 0 0 0 0

0118 0935 63 84 32 14.95 12 09.72 3378 NB2 1 0 1 1 1 0 1 1 1 0 1 1 0 1 1

0118 1104 -9 -9 32 14.87 11 58.24 -9 R214 RAFOS float 214

0118 1335 64 85 32 15.02 11 24.91 3337 NB2 1 1 1 1 1 1 1 1 0 1 1 0 0 0 0

0118 1850 64 86 32 14.94 11 24.90 3334 NB2 1 0 1 1 0 1 1 1 1 0 1 0 0 1 1

0118 2203 65 87 32 15.95 10 50.06 3240 NB2 1 1 1 1 0 1 1 1 0 1 1 0 0 0 1

0119 0430 65 88 32 15.06 10 50.00 3233 NB2 1 0 1 1 0 1 1 1 1 0 1 1 0 1 1

0119 0648 66 89 32 10.07 10 31.88 3001 NB2 1 1 1 1 1 0 1 1 0 0 1 0 0 0 1

0119 1305 66 90 32 09.98 10 31.88 2986 NB2 1 0 1 1 1 0 1 1 1 0 0 0 0 1 1

0119 1452 67 91 32 07.19 10 14.83 2074 NB2 1 1 1 1 0 1 1 1 0 0 1 0 0 0 1

0119 2037 67 92 32 06.76 10 14.90 2011 NB2 1 0 1 1 0 1 0 1 1 0 1 1 0 1 1

0119 2203 68 93 32 04.85 10 05.87 1219 NB2 1 1 1 1 1 1 1 1 0 0 1 0 0 0 1

0120 0220 69 94 32 02.71 09 55.42 908 NB2 1 0 1 1 0 0 1 1 1 0 1 0 0 0 0

0120 0555 69 95 32 02.55 09 55.45 1026 NB2 1 0 1 0 0 0 0 0 0 0 0 1 0 1 1

0120 0705 70 96 32 02.72 09 54.60 501 NB2 1 1 1 1 1 1 1 1 1 0 1 0 0 0 1

0120 0922 71 97 32 02.21 09 53.90 265 NB2 1 0 1 1 1 1 1 1 1 0 1 1 0 1 0

0120 1137 72 98 32 01.94 09 51.87 107 NB2 1 0 1 1 1 1 0 1 1 0 0 1 0 1 0

0121 2356 -9 -9 29 06.4 15 13.6 3592 XBT01

0122 0037 -9 -9 29 00.0 15 14.6 3598 XBT02

0122 0136 -9 -9 28 50.0 15 16.2 3594 XBT03

Parameter no

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

Date Time St Pr Latitude Longitude Wd Inst 1 2 3 4 5 6 7 8 9 10 11 12 13
14 15

UTC UTC North West 0 not sampled

MMDD hhmm GG MM.MM GG MM.MM \[m\] 1 sampled

1996/97

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

0122 0246 -9 -9 28 40.0 15 17.7 3584 XBT04

0122 0400 -9 -9 28 30.0 15 19.2 3472 XBT05

0122 0510 -9 -9 28 20.0 15 29.9 3148 XBT06

0122 0630 Call port of Las Palmas, end of M37/2

## References

## Aanderaa (1995): Operating Manual RCM 7 & 8. Techn. Descr. No. 159. Aanderaa Instruments, Bergen, Norway, 

## Cauwet, G (1994): HTCO method for dissolved organic carbon analysis in seawater: influence of catalyst on blank estimation. Mar. Chem. 47. 55-64.

## Doe (1994). Handbook of methods for the analysis of the various parameters of the carbon-dioxide system in sea water, Version 2, A.G. Dickson and C. Goyet (eds.), ORNL/CDIAC-74.

## Fischer, J. and M. Visbeck (1993): Deep Velocity Profiling with Self-contained ADCPs. Journ. Atm. Oc. Techn., Vol. 10, 764 - 773.

## Gelado-Caballero,M.D., J.J. Hernández-Brito, M.E. Torres-Padrón, J.A. Herrera-Melian and J. Pérez-Peña (1996): Aluminium distributions in Central East Atlantic Waters (Canary Islands). Mar. Chem, 51, 4, 359-372. 

## Hedges, J. I. (1992): Global biogeochemical cycles: progress and problems. Mar. Chem. 39. 67-93.

## Hedges, J. I. & C. Lee, (eds.) (1993): Measurement of dissolved organic carbon and nitrogen in natural waters. Proceedings of NSF/NOAA/DOE Workshop, Seattle, WA, USA. 290 pp.

## Hernández-Brito, J.J., M.D. Gelado-Caballero, J. Pérez-Peña and J.A. Herrera-Melián (1994): Fast Determination of Aluminum Reactive to 1,2-Dihydroxyanthra-quinone-3-sulfonic Acid in Sea-water. Analyst, 119, 1593-1597..

## Hernández-Brito, J.J., P. Cardona-Castellano, V. siruela-Matos and J. Pérez-Peña (1994): A High-Speed Computerized Polarographic System for Cathodic Stripping Voltammetry in Seawater. Electroanalysis, 6, 1141-1146.

## Johnson, K.M, K.D. Wills, D.B. Butler, W.K. Johnson and C.S. Wong (1993). Coulometric total carbon dioxide analysis for marine studies: automation and calibration. Mar. Chem., 44, 167-187.

## Llinas, O. A. Rodriguez de Leon, G. Siedler, G. Wefer (editors,): ESTOC data reprot. Inf. Tech. del Inst. Can. C. Mar., Nu. 3, Telde de Gran Canaria, 1997.

## Millero, F. J., J.- Z. Zhang, K. Lee, D. M. Campbell (1993). Titration alkalinity of seawater. Mar. Chem., 44, 153-165.

## Mintrop, L., The VINDTA manual, Version 2.0 (June 1996, unpubl.).

## Müller, T.J., J. Holfort, F. Delahoyde, and R. Williams (1995): MKIIIB-CTD: improving its system output. Deep-Sea Res I, Vol. 42, No. 11/12, 2113-2126.

## RDI (1989): Acoustic Doppler Current Profilers - Principles of Operation: A Practical Primer. RD Instruments, 36 pp. 

## Sharp, J., (1993): The dissolved organic carbon controversy: An update. Oceanography. 6. Nr. 2, 45-50.Sugimura, Y. & Y. Suzuki (1988): A high-temperature catalytic oxidation method for the determination of non-volatile dissolved organic carbon in seawater by direct injection of a liquid sample. Mar. Chem. 24. 105-131.

## Suzuki, Y. (1993): On the measurement of DOC and DON in seawater. Mar. Cem. 41. 287-288.

## WOCE (1994): WOCE Operations Manual, Vol. 3, Sect. 3.1, Part 3.1.3: WHP Operations and Methods. Rev. 1, Nov. 1994. Woods Hole, Mass. USA.

## 

## Figures

**Fig 1:** Station Map M37/2a (upper panel) and M37/2b (lower panel)
with positions of CTD casts (o), moorings (\*), and launched floats (x)
and XBTs (+).

**Fig. 2**: Currents at the ESTOC position, starting in September 1994;
moorings V367100 and V367200. Upward is north.

**Fig. 3**: Residuals of the salinity calibration of the MKIIIB CTD
(IFMK internal code NB2).

**Fig. 4:** Distribution of potential temperature and salinity along
29°N (Fig. 4a, b), 18°W (Fig. 4c, d), and 32°N (Fig. 4e, f).

####### **Fig. 5**: Near surface currents as measured with the vessel mounted ADCP

####### **Fig. 6**: Design of the GeoB drifting trap mooring.

######## **Fig. 7:** Coupling of the optical sensors.

**Fig. 8:** Information which can be obtained by measuring optical
parameters.

**Fig. 9:** Distribution of temperature, salinity, chlorphyll and
gelbstoff at the Meddy 'Jani' station 63.

**Fig. 10:** Distribution of total Carbon along the 29°N, 18°W and the
32°N sections. The view onto the sections is from the east.

![](media/image2.emf){width="6.75in" height="9.527777777777779in"}

**Fig 1:** Station Map M37/2a (upper panel) and M37/2b (lower panel)
with positions of CTD casts (o), moorings (\*), and launched floats (x)
and XBTs (+).

![](media/image3.emf){width="7.1194444444444445in"
height="8.400694444444444in"}

**Fig. 2**: Currents at the ESTOC position, starting in September 1994;
moorings V367100 and V367200. Upward is north.

![](media/image4.emf){width="6.083333333333333in"
height="4.638888888888889in"}

**Fig. 3**: Residuals of the salinity calibration of the MKIIIB CTD
(IFMK internal code NB2).

![](media/image5.emf){width="7.138888888888889in"
height="9.680555555555555in"}

**Fig. 4a:** Distribution of potential temperature along 29°N.

![](media/image6.emf){width="7.138888888888889in"
height="9.680555555555555in"}

**Fig. 4b:** Distribution of salinity along 29°N.

![](media/image7.emf){width="7.138888888888889in"
height="9.680555555555555in"}

**Fig. 4c:** Distribution of potential temperature along18°W.

![](media/image8.emf){width="7.138888888888889in"
height="9.680555555555555in"}

**Fig. 4d:** Distribution of salinity along18°W.

![](media/image9.emf){width="7.138888888888889in"
height="9.680555555555555in"}

**Fig. 4e:** Distribution of potential temperature along 32°N.

![](media/image10.emf){width="7.138888888888889in"
height="9.680555555555555in"}

**Fig. 4f:** Distribution of salinity along 32°N.

####### ![](media/image11.emf){width="7.115972222222222in" height="8.164583333333333in"}

####### **Fig. 5a**: Currents between 21 m and 175 m as measured with the vessel mounted ADCP 

####### ![](media/image12.emf){width="7.115972222222222in" height="8.164583333333333in"}

####### **Fig. 5b**: Currents between 175 m and 375 m as measured with the vessel mounted ADCP

![](media/image13.emf)

####### **Fig. 6**: Design of the GeoB drifting trap mooring 

![](media/image14.emf){width="6.295138888888889in"
height="3.848611111111111in"}

######## **Fig. 7:** Coupling of the optical sensors

![](media/image15.emf){width="6.127083333333333in"
height="4.115972222222222in"}

**Fig. 8:** Information which can be obtained by measuring optical
parameters.

  ----------------------------------------------------- ----------------------------------------------------- -----------------------------------------------------
  ![](media/image16.emf){width="3.0972222222222223in"   ![](media/image17.emf){width="3.0972222222222223in"   
  height="4.480555555555555in"}                         height="4.480555555555555in"}                         

                                                                                                              

  ![](media/image18.emf){width="3.0972222222222223in"                                                         ![](media/image19.emf){width="3.0972222222222223in"
  height="4.480555555555555in"}                                                                               height="4.480555555555555in"}
  ----------------------------------------------------- ----------------------------------------------------- -----------------------------------------------------

**Fig. 9:** Distribution of temperature, salinity, chlorphyll and
gelbstoff at the Meddy 'Jani' station

63![](media/image20.emf){width="5.166666666666667in"
height="7.319444444444445in"}

**Fig 10:** Distribution of total Carbon along the 29°N, 18°W and the
32°N sections. The view is onto the sections from the east.