P21

• Nitrate
• Phosphate
• Silicate
• Oxygen
• TCO₂ (Millero - RSMAS) - No addjustment recommended.
• Crossovers:
  

  Crossing #	Latitude	Longitude	WOCE Line	Station(s) used	Crosses with	Station(s) used	Delta TCO2	Stdev TCO2
  42	17° S	170° W	P21	141,142,144	P14S15S	193,195,197	2.3	0.4
  53c	17° S	150° W	P21	222	P16C	157,160	1.4	1.4
  53e	17° S	150° W	P21	220	P16S17S	157,160	0.8	1.0
  53f	17° S	150° W	P21	157,160	P31	2,5	2.7	3.3
  65	16° S	133° W	P21	148	P16S17S	131	0.5	1.7
  74	17° S	103° W	P21	105,106	P18	77	2.7	1.5
  80	16° S	86° W	P21	333	P19	49	3.1	0.9
  MEAN							1.9	1.0

• Precision of Duplicate Measurements - No Information.
• CRM Results - Shipboard measurements off by 0.9 ± 1.1. Data were adjusted for offset.
• Keeling Replicates- Mean difference for 15 samples was -2.25 ± 1.49
• Alkalinity (Millero - RSMAS) - No adjustment recommended.
• Crossovers:
  

  Crossing #	Old #	Latitude	Longitude	Cruise 1	Cruise 1 Sta	Cruise 2	Cruise 2 Sta	TALK Delta Stdev
  42	6	17° S	170° W	P14S15S	141,142,144	P21	193,195,197	0.34 ± 0.35
  53c	20	17° S	150° W	P16C	222	P21	157,160	-0.4 ± 2.2
  53e	53	17° S	150° W	P16S17S	220	P21	157,160	7.1 ± 0.9
  53f	21	17° S	150° W	P31	2,5	P21	157,160	5.8 ± 3.5
  65	25	16° S	133° W	P16S17S	148	P21	131	-20.5 ± 1.7
  74	36	17° S	103° W	P18	105,106	P21	77	-0.5 ± 2.8
  80	40	16° S	86° W	P19	333	P21	49	-2.9 ± 1.6
  AVERAGE								-1.6 ± 9.1

• Precision of Duplicate Measurements - No Information.
• CRM Results - No Information.
• Internal Consistency Analysis (details) - Measured Alkalinity - calculated (pH&TCO₂) = 5.4 ± 4.8
• fCO₂ (Not Measured)
• pH (Millero - RSMAS) - We recommend adjusting all spectrophotometric pH values upward by 0.0047 to be internally consistent with the other carbon parameters. Note: pH was determined by potentiometry on P21E (station 3 to 160). On P21W (station 166 to 276), pH was measured by spectrophotometric technique using an indicator.
• Crossovers- No Information.
• Precision of Duplicate Measurements - No Information.
• CRM Results - No Information.