Underway Sulfur Dioxide measurements from R/V Tangaroa cruise VDT0410 in the South East of New Zealand, S.W. Bounty Trough in 2004 (SAGE project)

<p>Underway Sulfur Dioxide Measurements<br />
<br />
<b>Notes on Sulfur Dioxide Measurements made during the SAGE Cruise; 27 March to 15 April 2004</b><br />
Measurements were made using an HPLC technique: <br />
Saltzman, E.S., Yvon, S.A. and Matrai, P.A. 1993. Low-level atmospheric sulfur dioxide measurement<br />
using HPLC/fluorescence detection. J. Atmos. Chem., 17, 73-90 <br />
<br />
Measurements commenced on 01 April 2004<br />
The following days there were no measurements made:<br />
02 April 2004<br />
07 April 2004 <br />
08 April 2004 <br />
10 April 2004 <br />
11 April 2004 <br />
12 April 2004 <br />
<br />
On these days either the weather was too bad for operation or deployment of the<br />
ship meant that sampling of the stack was highly likely. The inlet of the instrument<br />
was on the seaward side of the Atmospheric Container lab and it was imperative to<br />
ensure that seawater did not enter the inlet, since seawater would have acted as<br />
a sink for sulfur dioxide and would have damaged the nafion drier beyond repair.<br />
In poor weather waves were breaking over the container occasionally, the instrument<br />
was not operated in such conditions.<br />
<br />
13 April 2004 was a dedicated &quot;Atmospheric&quot; day and sampling ran for 12 hours,<br />
commencing at 04:15am, to obtain pre-dawn levels of sulfur dioxide.<br />
<br />
The cleanest days of the cruise, when the measurements were not significantly affected<br />
by ship emissions were 09 April and 13 April. 09 April 2004 was the cleanest day with<br />
all measurements likely to be from clean background air <br />
<br />
A further assessment of how clean samples were, will be made using the CN data at a later stage.<br />
<br />
The inlet was at a height of 2m from the deck and 1m from the rail. </p>