P17C

• Nitrate (SIO)
• Phosphate (SIO)
• Silicate (SIO)
• Oxygen (SIO)
• TCO₂ (C. Goyet, WHOI) - No adjustment recommended.
• Crossovers:
  

  Crossing #	Latitude	Longitude	WOCE Line	Station(s) used	Crosses with	Station(s) used	Delta DIC	Stdev DIC
  60b	35° N	135° W	P17C	12	CGC91	17	-5.7	3.7
  60c	35° N	135° W	P17C	28	P17N	17	-9.4	3.4
  61	30° N	135° W	P17C	26	P2	78	-3.1	4.6
  64	6° S	135° W	P17C	121	P16S17S	124	-1	2.5
  MEAN							-4.8	3.6

• Precision of Duplicate Measurements - No information.
• CRM Results - CRMs used as primary standard.
• Keeling Replicates - Mean difference for 40 samples was -3.41 ± 4.00.
• Multiparameter Analysis (details) - Mean Difference (estimated - measured) = -0.5 ± 4.1
• Isopycnal Analysis - In the region near 37± N, 135± W, the isopycnal analysis indicated that the P17N data are consistently higher (range: 6-16 µmol/kg) than the P17C and CGC91 data (Figure). The CGC91 data agree reasonably well with the P17C results at higher densities, but are somewhat higher at the lowest densities. The crossover and MLR analyses of P17N indicate that the P17N data need to be decreased by 3-10 µmol/kg. An average decrease of ~6 µmol/kg in P17N will account for most of the observed differences with P17C and CGC91, but not all of the observed 6-16 µmol/kg range. The MLR techniques suggest that CGC91 should be increased by 4-5 µmol/kg, but the crossover results are much smaller and none of the techniques indicate a large correction is necessary for P17C. All of these results cannot be reconciled, but a small increase of ~2 µmol/kg in both CGC91 and P17C would minimize all of the observed offsets from the various approaches.
• Alkalinity (C. Goyet, WHOI) - Adjustment of -9 µmol/kg recommended.
• Crossovers:
  

  Crossing #	Old #	Latitude	Longitude	Cruise 1	Cruise 1 Sta	Cruise 2	Cruise 2 Sta	TA Delta Stdev
  64	26	6° S	135° W	P17C	121	P16S17S	124	0.8 ± 1.5 (graph)

• Precision of Duplicate Measurements - No information.
• Multiparameter Analysis (details) - Mean Difference (estimated - measured) = -8.7 ± 7.6
• Isopycnal Analysis - P17C and neighboring cruises were examined as a function of latitude for s-3 values between 41.44 and 41.51 (Figure). The larger density range was necessary to encompass enough data for comparison. The P17C data appear to be slightly higher than P16C or P15N. The low P2 data relative to P15N are also seen in the Figure.
• fCO₂ (Not Measured)
• pH (Not Measured)