Final Report for AMS 14 C Samples
G. Data Quality Evaluation
G.6. PI Response to Hydrographic DQE
(DQE Arnold Mantyla reviewed the Hydrographic Data) SUM file:
Bottom time and position added. Maximum pressure corrected.
Corrected errors in stations 14, 17, 21, 32, 69, 191 Double trips:
A common problem with double trips is that although the CTD pressure and temperature were identical, for some reason the CTD salinity and CTD oxygen were not (probably due to the program that overwrites the old file with new data).
These double trips were identified and the CTD salinity and CTD oxygen checked for accuracy.
CTD, Salinity and Oxygen quality code changed:
Agree almost entirely with DQE’s suggested changes.
Specific problems:
Station 8, bottle 2
Station log revealed no indication of a problem. Decided not to make up a new depth. If bottle did close at shallower depth then the bottle must have been closed while package was moving, which would also produce questionable results.
Station 9 Changed trip depth of bottle 11 to indicate bottle 11 and 12
double tripped at bottle 12’s depth. Changed quality word to good.
Station log depths for bottles 2 and 9 agree with depths in water sample file (*.hy2).
Oxygen water samples were not reported below 869db (lost in analyses?) thus 5 was used as the quality code. Trip depth not resolved, water samples (salt, oxygen and nutrients) marked questionable.
Station 10, btl. 17
Did not change trip depth. Bottle was a leaker, water sample data left as question-able.
Station 11, btl. 1
Oxygen looks too high in comparison to following stations that were also in the trench. Left oxygen quality code as questionable.
Station 13 Changed trip depth of bottle 7 to reflect bottle 7 double tripped with bottle 6 at bottle 6’s depth.
Bottle 6 is a leaker, water sample data is questionable. Bottle 20 oxygen probably was mistakenly drawn from bottle 21 but left quality code as bad.
Station 16, btls. 3, 8 and 9
Changed trip depths of bottles 8 and 9 to reflect bottle 8 double tripped with bottle 7, bottle 9 tripped at bottle 8’s former depth and no bottle tripped at bottle 9’s former depth. Changed bottle 8 and 9’s quality code to good.
Station 16, btls. 3, 8 and 9
Changed trip depth of bottle 3 to reflect bottle 3 double tripped with bottle 2 and no bottle tripped at bottle 3’s former depth.
Changed bottle 3’s quality code to good.
Station 17, btl. 8
Trip depth unresolved, flagged quality code of salt, oxygen and nutrients as questionable.
Station 19, btls. 5 and 6
Changed trip depths of bottles 5 and 6 to reflect no bottle tripped at bottle 5’s former depth, bottle 5 tripped at bottle 6’s former depth and bottle 6 double tripped with bottle 7 at bottle 7’s depth.
Changed bottle 5 and 6’s quality code to good.
Station 31, btl. 6
Changed nutrient data quality code to good. Nutrient data analyzer, Joe Jennings will review change.
Station 32 All salinity quality codes changed to questionable. Salinity analyzer, George Knapp did not find any reason to explain bad station data. There was no shift in the salinometer standby number.
Station 41, btls. 3 and 4
Bottle 3 salinity flagged as questionable. Bottle 4 salinity and oxygen flagged as bad.
Station 55, btl. 32
Oxygen analyzer, George Knapp remembers bottle 32 did indeed have an extremely high oxygen measurement. One wild guess is perhaps the iodine measured in the titration had been increased due to the ink of a squid?!
Station 64, btl. 21
Coincidence perhaps, probably not a typo, in any case bottle 21 quality code left as bad.
Stations 73 and 74
Instrument test stations only, not included in data set.
Station 79, 1964db
Sample lost in analyses, quality code changed to 5 (not reported).
Station 80, btl. 24
No mix-up found and unlikely a typo. Bottle 24 quality code left as bad.
Station 81, btls. 7 and 8
Quality code of all nutrients for bottles 7 and 8 were changed to questionable. Nutrient analyzer, Joe Jennings will review this change.
Station 89, btl. 20:
Oxygen quality code changed to questionable. Quality code of deep silica’s were changed to good. Nutrient analyzer, Joe Jennings will review this change.
Station 90, btls. 35 and 36:
Agree, that likely two surface salinity samples had been interchanged. No explanation found, so samples were not swapped, quality code was changed to questionable and CTD salinity quality code was changed to good.
Station 95: Left trip depths as they were and changed quality code of oxygen and nutrient data to questionable.
Station 97, btl.29:
Salinity typo corrected, both salinity and CTD salinity quality codes were set as good.
Station 101, btl.22 at 90m:
Changed trip depth to reflect bottle 22 double tripped with bottle 23 at bottle 23’s depth. Changed quality code to good.
Station 104, btls. 10, 11:
Changed bottle 10 and 11’s quality code to bad.
Station 113, btl. 19:
Original records show bottle was meant to trip at a depth near 250db. Changed trip depth, temperature, theta, CTD salt and CTD oxygen, to match original trip depth data. Changed quality code to good.
Station 143, btl. 8:
Original records show bottle was meant to trip at a depth 3967db.
Changed trip depth, temperature, theta, CTD salt and CTD oxygen, to match original trip depth data. Changed quality code to good.
Station 145, btl. 13:
Changed bottle 13 trip depth to reflect bottle 13 and 14 double tripped at bottle 14’s depth. Changed quality code to good.
Station 147, btl. 8:
Original records show bottle was meant to trip at a depth 4039db.
Changed trip depth, temperature, theta, CTD salt and CTD oxygen, to match original trip depth data. Changed quality code to good.
Station 148, btls. 11 and 12:
Changed trip depth of bottles 11 and 12 to reflect bottle 11 double tripped with bottle 10 at bottle 10’s depth and bottle 12 tripped at bottle 11’s former depth. Changed quality code to good.
Station 149, btl. 13:
Changed trip depth of bottle 13 to reflect bottle 13 double tripped with bottle 14 at bottle 14’s depth. Changed quality code of salinity to good but oxygen quality code left as questionable.
Station 195, btl. 31:
Changed trip depth of bottle 31 to reflect bottle 31 double tripped with bottle 32 at bottle 32’s depth. Changed quality code to good.
Station 229, PO4s:
Changed PO4s quality code to questionable for all observations below 900db. Nutrient analyzer, Joe Jennings will review this change.
Station 236, btls. 30 and 31 at 400 and 301db:
Changed trip depth of bottle 31 to reflect bottle 31 double tripped with bottle 30 at bottle 30’s depth. Changed quality code to good.
Station 238, PO4s:
Nutrient analyzer, Joe Jennings will review.
Stations 248 thru 267:
Stations are along cruise track and are considered part of the data set.