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Sensors were mounted on the bow mast. |
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| Closed-path gas analyzers and pumps were located in the bosun locker. |
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In December 2012 we installed an eddy
covariance system on the bow mast of the Nathaniel B. Palmer icebreaker to make
direct measurements of carbon dioxide flux
over the ocean. These data are being used
in conjunction with dpCO2
data obtained
from Taro Takahashi at LDEO (underway
system on the Palmer) to calculate the
gas transfer velocity. Previous research
on the wind speed dependence of the
gas transfer velocity (k vs U) has yielded a
variety of functional forms, ranging from
piecewise linear (Liss and Merlivat, 1986),
to quadratic (Sweeney
et al
., 2007), to
cubic (Wanninkhof and McGillis, 1999). At
low wind speeds there is good agreement
between the different parameterizations of
transfer velocities, but the range widens at
higher wind speeds (>15 m/s). Our goal was to make
measurements over a longer term than a
typical research cruise and collect
enough data to better constrain the gas transfer velocity. The system was deployed on eight cruises, mostly in the
Southern Ocean.
This research supported by the National Science Foundation award O-278-N.
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Ship tracks from the eight NBP cruises. (click the image to enlarge) |
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