Suggested water sampling protocols
August 15, 2005
Sample order
Chlorofluorocarbons
Oxygen
Total CO2
Alkalinity
Nutrients
Salinity
Biological samples (although salinity sample could in principle go later since the full volume of water is not necessarily needed for salinity)
(Example: WOCE A24 (1997)
Chlorofluorocarbons
Helium
Oxygen
pCO2
Total CO2
Alkalinity
Tritium
Nutrients
Salinity
dO18 )
Minimum sampling guidelines for 36 bottle cast:
(1) top bottle within sight of the surface
(2) bottom bottle within 10 meters of bottom
(3) 0-500 meters: spacing no greater than 50 meters
(4) 500-1000 meters: spacing no greater than 100 meters
(5) 1000-3000 meters: spacing no greater than 200 meters
(6) 3000 meters to bottom: spacing no greater than 300 meters
(7) bottom of SAMW: resolve the property break with one bottle above and one below if the layer is obvious (within 50 meters of break)
(8) AAIW if obvious salinity minimum (north of SAF): try to hit the minimum
General: stagger the sampling so that sample depths are not exactly the same from one to the next. Depending on the CFC and CO2 sampling, might need to make sure that they are also not exactly the same on adjacent CFC/CO2 stations (which might be every other station).
Example cast, in 4000 meters of water, 36 bottles
3
25
50
75
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
900
1000
1200
1400
1600
1800
2000
2200
2400
2600
2800
3000
3200
3400
3600
3900
< 10 meters from bottom
Minimum sampling guidelines for 24 bottle cast:
(1) top bottle within sight of the surface
(2) bottom bottle within 10 meters of bottom
(3) 0-about 500 meters: spacing no greater than 50-60 meters
(4) 500-800 meters: spacing no greater than 100 meters
(5) 800-1200 meters: spacing no greater than 200 meters
(6) 1200-2000 meters: spacing no greater than 350 meters
(7) 2000-bottom: spacing no greater than 500 meters
(8) bottom of SAMW: resolve the property break with one bottle above and one below if the layer is obvious (within 50 meters of break)
(9) AAIW if obvious salinity minimum (north of SAF): try to hit the minimum
General: stagger the sampling so that sample depths are not exactly the same from one to the next.
Example cast, in 4000 meters of water, 24 bottles
1
30
60
90
140
190
240
290
340
390
450
550
650
750
850
1000
1250
1500
1750
2100
2600
3100
3600
<10 meters off bottom
Examples from previous cruises crossing the ACC and SAMW region:
P16S (2005) (Sloyan and Swift)
WOCE P19S and P19C (1993) (Swift, Talley and Tsuchiya)
WOCE P18 (1994) (Bullister)
