P31

• Nitrate
• Phosphate
• Silicate
• Oxygen
• TCO₂ (Winn - UH) - No adjustment recommended.
• Crossovers:
  

  Crossing #	Latitude	Longitude	WOCE Line	Station(s) used	Crosses with	Station(s) used	Delta TCO2	Stdev TCO2
  41c	10° S	170° W	P31	157,159,161	P14S15S	54,57,61	2.6	2.2
  41e	10° S	170° W	P31	66	EQS92	54,57,61	0.8	5.8
  41f	10° S	170° W	P31	130,132	P15N	54,57,61	3.2	3.6
  53b	17° S	150° W	P31	222	P16C	2,5	-0.6	0.8
  53d	17° S	150° W	P31	220	P16S17S	2,5	-0.9	0.5
  53f	17° S	150° W	P31	157,160	P21	2,5	2.7	3.3
  MEAN							1.3	1.8

• Precision of Duplicate Measurements - No Information.
• CRM Results - Shipboard measurements off by -0.9 ± 2.7.
• Keeling Replicates - Mean difference for 8 samples was 0.21 ± 3.42.
• Alkalinity (Winn - UH) - Adjustment of -6 µmol/kg recommended.
• Crossovers:
  

  Crossing #	Old #	Latitude	Longitude	Cruise 1	Cruise 1 Sta	Cruise 2	Cruise 2 Sta	TALK Delta Stdev
  41c	10	10° S	170° W	P14S15S	157,159,161	P31	54,57,61	-0.5 ± 3.5
  41e		10° S	170° W	EQS92	66	P31	54,57,61	-7.3 ± 2.3
  41f	51	10° S	170° W	P15N	130,132	P31	54,57,61	-3.2 ± 0.9
  53b	22	17° S	150° W	P16C	222	P31	2,5	-3.5 ± 0.9
  53d	54	17° S	150° W	P16S17S	220	P31	2,5	-6.5 ± 1.1
  53f	21	17° S	150° W	P21	157,160	P31	2,5	-5.8 ± 3.5
  AVERAGE								-4.5 ± 2.5

• Precision of Duplicate Measurements - No Information.
• CRM Results - No Information.
• Internal Consistency Analysis (details) - Measured Alkalinity - calculated (pH&TCO₂) = -1.3 ± 5.8
• Isopycnal Analysis - P31 was compared with a nearly parallel cruise (P21) that was run along 20° S and the intersecting meridional cruises P15N, P15S, and P16C (Figure). The P31 data at either end of the section, where the meridional lines intersect, are only slightly higher than the other lines. In the middle of the section, however, the P31 data are much higher than the P21 values suggesting that a correction is in order.
• fCO₂ (Not Measured)
• pH (Winn - UH) - We recommend adjusting all spectrophotometric pH values upward by 0.0047 to be internally consistent with the other carbon parameters.
• Crossovers:
  

  Crossover	Longitude	Latitude	Cruise-1	Stations-1	Cruise-2	Stations-2	Δ Salinity	Δ O2	ΔpH	Feely et al. #
  41	170° W	10° S	P14S15S	159,161	P31	61,64	0.001 ± 0.002	0.0 ± 2.6	-0.0005 ± 0.0003	10

  From Feely et al., 1999, ORNL/CDIAC-115 (Δ = Cruise 1 - Cruise 2)

 

Crossover	Longitude	Latitude	Cruise-1	Stations-1	Cruise-2	Stations-2	ΔpH	Feely et al. #
41	170° W	10° S	P14S15S	159,161	P31	61,64	-0.0049 ± 0.001	10

From study by Frank Millero (Δ = Cruise 1 - Cruise 2)
• Precision of Duplicate Measurements - No Information.
• CRM Results - No Information.