Indian Ocean 1995 - Leg 8C Readme
About the Cruise:
From February 1995 through January 1996 the NOAA Ship MALCOLM BALDRIGE
conducted scientific operations on an around-the-world cruise to the
Indian Ocean. Samples were taken from both the surface water and the
overlying atmosphere to determine carbon dioxide flux across the gas/
water interface. The ship departed Rodman, Panama on January 20, 1996
and arrived in Charleston, South Carolina on January 29, 1996.
Class of Data: Surface ocean carbon dioxide concentrations
Dataset Identifer: IO95_Leg8C
Statement of how to cite dataset:
BALDRIGE website: http://www.aoml.noaa.gov/ocd/gcc/baldrige_introduction.php
For more information on dataset citation please see Master Readme File.
Measurement platform identifier: IO95_Leg8C/NOAA Research Vessel MALCOLM BALDRIGE
Data quality issues:
Method of Analysis: Infrared absorption of dried gas.
Standard Gases and Reference Gas: The three standard gases come from CMDL
in Boulder and are directly traceable to the WMO scale. The reference gas
is a non-calibrated gas from a commercial company. Any value outside the
range of the standards (300 ppm, 360 ppm, and 420 ppm) should be considered
approximate (5 ppm). While individual data points above 420 or below 300 may
not be accurate, the general trends should be indicative of the seawater
chemistry.
Sampling Cycle: The system runs on an hourly cycle during which three
standard gases, three air samples from the bow mast and eight surface water
samples (from the equilibrator head space) are analyzed on the following
schedule:
Minutes after the hour Sample
4 Low Standard
8 Mid Standard
12 High Standard
16 Water
20 Water
25 Water
29 Water
33 Air
37 Air
41 Air
46 Water
50 Water
55 Water
59 Water
The two water values are averaged to yield a single hourly value which is merged
with the air value to determine the air-water difference in fugacity (delta fCO2).
The time stamp and location are for the top of the hour after the air and two
water sample analyses.
Units: All xCO2 values are reported in parts per million (ppm) and are for
dry gas and fCO2 values are reported in microatmospheres (uatm) assuming
100% humidity at the equilibrator temperature. Columns have a default value
of -9 in case of instrument malfunction or erroneous readings. Furthermore,
if a questionable xCO2 value, pressure, or temperature value is encountered
which cannot be readily extrapolated a default value of -9 is placed in
that field.
Contact persons for this dataset:
Rik Wanninkhof
(305)361-4379
Rik.Wanninkhof@noaa.gov
Betty Huss
(305)361-4395
Betty.Huss@noaa.gov
Timestamp for dataset reduction:
Timestamp for most recent update of dataset: 3/16/2006
Note: Corrected the Julian Day for the month of January in
date file.
Time period the dataset refers to: 1/20/1996 - 1/29/1996
Geographic area the dataset refers to:
Leg 8C Start: Rodman, Panama (January 20, 1996)
Leg 8C End: Charleston, South Carolina (January 29, 1996)
Leg 8C: Rodman, Panama to Charleston, South, Carolina
Chief Scientist(Leg 8C): Linda Magnum
David Zimmerman
System Operators (Leg 8C): Jason Masters, AOML