SailCTD_Arch Variables

SailCTD_arch.dat contains CTD data gathered with our CTD mounted 
in the sail of the USS Pargo during SCICEX '93.  We measured 
temperature and salinity with Sea-Bird SBE-16 CTD, Ser # 914, 
recording internally at 2 minute intervals (we wish to thank 
Miles McPhee for loaning us SBE-16 #914).  The CTD was 
mounted in the Sail of the USS Pargo.  It received water from 
an Ocean Sensors Inc CTD  and Sea-Bird pump through 3 m of 
1.9 cm hose.  The OSI and Sea-Bird Pump were  fed through 
approx 3 m of hose from a port at the top of the sail. The 
OSI CTD and pump were installed by the Arctic Submarine Lab.  
The measurement depth given here has been corrected to about 
a 3 dbar greater depth than that measured by the CTD.  This 
depth correction was made on the basis of comparison with 
normal surface lowered CTD casts, and accounts for deflection 
of the flow around the hull, i.e. the measurement depth is 
the depth of the sampled water undisturbed by the submarine's 
passing. Based on examination of the raw data after a rapid 
change in depth, we think the flushing time is rather long, 
approximately 30-40 minutes for full adjustment to a rapid 
change in salinity.  We think this is due to two things.  
First, the approx 6 m of 3/4" hose leading to the CTD has a 
substantial flushing time.  Second, the inlet is mounted aft 
of the forward cockpit, so water slowly flushes out of the 
sail through the loose fitting cockpit hatch and into the CTD 
system.  No attempt has been made to correct for the long 
flushing time.  If you have questions contact Jamie Morison 
(morison@apl.washington.edu) or Roger Andersen 
(roger@apl.washington.edu).

         Good luck,

           Jamie Morison


The variables in SailCTD_Arch are by column:
 
Column 
 1  day of 1993
 2  latitude  interpolated from Quartermasters Log
 3  Longitude interpolated from Quartermasters Log
 4  ocean depth (m) interpolated from Quartermasters Log
 5  grid x (km) *
 6  grid y (km) *
 7  measurement depth (dbar)
 8  temperature (¡C), interpolated across surfacings
 9  conductivity (S/m), interpolated across surfacings
10  salinity, interpolated across surfacings
11  Sigma theta (kg/m3) , interpolated across surfacings
12  measurement depth (dbar), interpolated across surfacings

* grid x along 90¡E from the pole, grid y is along 180¡ from
 the pole