1. LT Anna C. (Christy) Bryant
Compiling Nutrient Data on CalCOFI Line 67 for a Spring and Fall Cruise.
LT Anna C. (Christy) Bryant

2. The Data Would Not Be Ready
Objective
Analyze data regarding nutrients taken during the CTD casts during Leg 1 of OC3570 cruise.
Unfortunately...
The Data Would Not Be Ready

3. Solution Use data from a September, 2000 cruise
And just to see the differences…added in a data set from a May 2000 cruise

4. Background
Chemistry
Physics
Biology

5. CalCOFI Grid
Monterey
Bay
CalCOFI Line 67

6. Upwelling Index Location

7. The Data Occasional instances of ‘no data’
Bottles not measured
Depth of last bottle varied
None of the data was “square”
Linear interpolation was used to square it
Cruises covered different distances
One was 425 km, one was 275 km

8. Some Data Points “no data”

9. Other “no data” points were treated...

10. “Squaring Data”
* Collection Points
- Interpolated line

11. Nutrients Consistently tested were:
SiO4 (Silicate)
PO4 (Phosphate)
NO3 (Nitrate)
Nitrate is the limiting macronutrient for phytoplankton in these waters (typically).
(Pennington and Chavez, 2000)

12. NO3 in M/l
May 2000
Sept 2000

13. May 2000
Sept 2000

14. NO3 Profiles Sept 2000 May 2000 NO3 M/l NO3 M/lD E P T H
(m)
NO3 M/l
NO3 M/l
Profiles progress from C1 towards the west. Sept goes to 425km off the coast, while May only goes to 275 km.

15. Sept-May 2000 NO3 Contour September has less near shore
September has more off-shore

16. April/May Significantly Higher than Sept nearshore
Upwelling Index taken from Upwelling Index Update, U.S. West Coast, 33N-48N Latitude Units in Cubic Meters per Second per 100 Meters of Coastline
April/May Significantly Higher than Sept nearshore

17. PO4 in M/l
May 2000
Sept 2000

18. SiO4 in M/l
May 2000
Sept 2000

19. Temp (ºC)
May 2000
Sept 2000

20. Difference Contours

21. Summary and Conclusions
1) Nutrients showed very similar profiles along the CalCOFI line for May and September, 2000.
2) Higher values of nutrients in the vicinity of the M1/H3 station for May are in keeping with the averaged Upwelling Index for locations just South and North of the station.
3) Data from several more cruises would have been more illuminating, perhaps one per month. Once the program problems were fixed, creating more profiles doesn’t take much time.

22. Questions??