DATA DESCRIPTION FOR FILE \<06MT20021013.csv\>

CONTRIBUTORS

Douglas W.R. Wallace (CHIEF SCIENTIST)

Leibniz Institute of Marine Sciences at Kiel University\
Marine Biogeochemistry\
Duesternbrooker Weg 20\
D-24105 Kiel,\
Germany\
Email: <dwallace@ifm-geomar.de>

SCOPE

Hydrographical and chemical data made during the German Meteor 55 (M55)
cruise in the tropical North Atlantic. Start of cruise: 2002.10.13 in
Willemstad. End of cruise: 2002.11.17 in Duala.

# DATA DESCRIPTION

The methods, corrections and post-cruise calibration procedures are
described below.

CTD WORK

The temperature and salinity are reported on the ITS-90 and PSS-78
calibration scales, respectively. For more information regarding CTD
data, contact Jens Schafstall (<jschafstall@ifm-geomar.de>). The CTD
underwater unit was a SBE 9+.

TOTAL ALKALINITY

Potentiometric titration \[Mintrop et al., 2000\].

CRM corrected from batch 60. The mean difference between measurements
and the Certified values was 0.8 2.37 mol kg^-1^ (95% confidence
interval, n=16). Alkalinity values have been adjusted to the certified
value by addition of this mean offset. The alkalinity samples were
measured after the cruise in the lab in Kiel.

DISSOLVED INORGANIC CARBON (DIC)

Coulometric titration \[Johnson et al., 1993\].

CRM corrected from batch 60. Mean offset between our measurements and
the Certified Values was 0.12 0.84 mol kg^-1^ (95% confidence interval,
n = 17). Measured DIC concentrations were therefore adjusted to the
Certified calibration scale by subtraction of this mean offset. The DIC
samples were measured after the cruise in the lab in Kiel.

OXYGEN

Oxygen measurements performed by Frank Malien (<fmalien@ifm-geomar.de>)
by means of Winkler titration.

NUTRIENTS

Nutrient analysis performed by Frank Malien (<fmalien@ifm-geomar.de>).

The relative standard deviation of the high standard concentration was
less than 1%.

The ammonium data are noisy, and are all flagged.

DATA FORMAT

The data are supplied in comma separated format (.csv).

Units for nutrients, oxygen, DIC and alkalinity are umol/kg.

Missing data are denoted with --999.

OTHER MESUREMENTS

N~2~O; Contact Hermann Bange (<hbange@ifm-geomar.de>)

Carbon isotopes; Contact Douglas Wallace (<dwallace@ifm-geomar.de>)

Bioincubations; Contact Matthew Mills (<mmmills@stanford.edu>)

Trace metals; Contact Peter Croot (<pcroot@ifm-geomar.de>)

Brominated organohalgens and light alkyl nitrates; Contact Douglas
Wallase (<dwallace@ifm-geomar.de>).

Underway pCO2: Contact Arne Körtzinger (<akoertzinger@ifm-geomar.de>).

DMS: Contact Hermann Bange (<hbange@ifm-geomar.de> ).

Chlorophyll a, phytoplankton pigments, flow cytometry, Utermöhl
microscopy, particulate phosphorus, POC, PON, N-15 and C-13 in
particulate matter, particulate biogenic silica, total seston: Contact
Ilka Pekeen (<ipekeen@ifm-geomar.de> ).

See cruise report for more information on measurements and preliminary
results.

REFERENCES

Mintrop, L., F.F. Perez, M. Gonzalez-Davila, J.M. Santana-Casiano, and
A. Körtzinger (2000), Alkalintiy determination by potentiometri:
intercalibration using three different methods, Scienc. Mar., 26, 1,
23-37.

Johnson, K., K.D. Willis, D.B. Butler, W.K. Johnson, and C.S. Wong
(1993), Coulometric carbon dioxide analysis for marine studies:
Maximizing the performance of an automated gas extraction system and
coulometric detector, Mar. Chem., 44 (2-4), 167-188.

[Articles based on data collected during the M55 cruise]{.underline}

Mills, M.M., C. Ridame, M. Davey, J. LaRoche, R. Geider, Iron and
phosphorus co-limit nitrogen fixation in the eastern tropical North
Atlantic, Nature 429, 292 - 294 (20 May 2004); doi:10.1038/nature02550

Gros V., J. Williams, M. G. Lawrence, R. von Kuhlmann, J. van Aardenne,
E. Atlas, A. Chuck, D. P. Edwards, V. Stroud, M. Krol (2004), Tracing
the origin and ages of interlaced atmospheric pollution events over the
tropical Atlantic Ocean with in situ measurements, satellites,
trajectories, emission inventories, and global models, J. Geophys. Res.,
109, D22306, doi:10.1029/2004JD004846.

Walter, S., Bange, H.W., Breitenbach, U. and Wallace, D.W.R., 2006.
Nitrous oxide in the North Atlantic Ocean. Biogeosci., 3: 607-619.

Baker, A.R., Weston, K., Kelley, S. D., Voss, M., Streu, P., and Cape,
J. N., 2007. Dry and wet deposition of nutrients from the tropical
Atlantic atmosphere: Links to primary productivity and nitrogen
fixation. Deep-Sea Res. I, in press.

Williams, J., Gros, V., Atlas, E., Macieczyk, K., Batsaikhan, A.,
Schoeler, H.F., Forster, C., Quack, B., Yassaa, N., Sander, R., and Van
Dingenen, R., 2007. Possible evidence for a connection between methyl
iodide emissions and Saharan dust. J. Geophys. Res., 112: D07302,
doi:10.1029/2005JD006702.

[Geophysical Research Letters Special Section]{.underline}

Baker, A. R. (2004), Inorganic iodine speciation in tropical Atlantic
aerosol, Geophys. Res. Lett., 31(23), L23S02, doi:10.1029/2004GL020144.

Croot, P. L., P. Streu, and A. R. Baker (2004), Short residence time for
iron in surface seawater impacted by atmospheric dry deposition from
Saharan dust events, Geophys. Res. Lett., 31(23), L23S08,
doi:10.1029/2004GL020153.

Croot, P. L., P. Streu, I. Peeken, K. Lochte, and A. R. Baker (2004),
Influence of the ITCZ on H~2~O~2~ in near surface waters in the
equatorial Atlantic Ocean, Geophys. Res. Lett., 31(23), L23S04,
doi:10.1029/2004GL020154.

Körtzinger, A., A significant CO2 sink in the tropical Atlantic Ocean
associated with the Amazon River plume, Geophys. Res. Lett., 30(24),
2287, doi:10.1029/2003GL018841, 2003.

Quack, B., E. Atlas, G. Petrick, V. Stroud, S. Schauffler, and D. W. R.
Wallace (2004), Oceanic bromoform sources for the tropical atmosphere,
Geophys. Res. Lett., Geophys. Res. Lett., 31(23), L23S05,
doi:10.1029/2004GL020597.

Richter, Uwe; Wallace, Douglas W. R., Production of methyl iodide in the
tropical Atlantic Ocean, Geophys. Res. Lett., 31(23), L23S03,
doi:10.1029/2004GL020779.

Voss, M., P. Croot, K. Lochte, M. Mills, and I. Peeken (2004), Patterns
of nitrogen fixation along 10°N in the tropical Atlantic, Geophys. Res.
Lett., 31(23), L23S09, doi:10.1029/2004GL020127.

Walter, S., H. W. Bange, and D. W. R. Wallace (2004), Nitrous oxide in
the surface layer of the tropical North Atlantic Ocean along a west to
east transect,, Geophys. Res. Lett., 31(23), L23S07,
doi:10.1029/2004GL019937.

Wallace, D. W. R., and H. W. Bange (2004), Introduction to special
section: Results of the Meteor 55: Tropical SOLAS Expedition, Geophys.
Res. Lett., 31, L23S01, doi:10.1029/2004GL021014.

Williams, J., R. Holzinger, V. Gros, X. Xu, E. Atlas, and D. W. R.
Wallace (2004), Measurements of organic species in air and seawater from
the tropical Atlantic, Geophys. Res. Lett., 31(23), L23S06,
doi:10.1029/2004GL020012.