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Physical-biological interactions: regional to basin scales

Physical-biological interactions: regional to basin scales. I. Pseudocalanus spp.: MARMAP data 1977-1987 II. P. moultoni and P. newmani : U.S. Globec Georges Bank broadscale surveys in 1997 III. Calanus finmarchicus : U.S. Globec Georges Bank broadscale surveys 1995-1999

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Physical-biological interactions: regional to basin scales

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  1. Physical-biological interactions:regional to basin scales I. Pseudocalanus spp.: MARMAP data 1977-1987 II. P. moultoni and P. newmani: U.S. Globec Georges Bank broadscale surveys in 1997 III. Calanus finmarchicus: U.S. Globec Georges Bank broadscale surveys 1995-1999 IV. Toward a basin scale approach: lessons from the JGOFS program on physical-biogeochemical interactions at large scales

  2. General circulation during the stratified season Beardsley et al. (1997)

  3. A finite-element model of the Gulf of Maine / Georges Bank region (Lynch et al., 1996)

  4. Pseudocalanus spp.MARMAP 1977-1987 Two population centers: Western Gulf of Maine Georges Bank Davis (1984) hypothesis: Western Gulf of Maine is a source region for the Georges Bank population Concentration (# m-3)

  5. A first attempt to simulate the observed Pseudocalanus spp. distributions…

  6. 1997 Broadscale Survey Data P. moultoni P. newmani Species-specific PCR (Bucklin et al., 2001)

  7. Observations: P. Moultoni Models Observations: P. newmani

  8. Are the inverse solutions ecologically realistic? R(x,y,t) bounded by –100 to +100 individuals m-3 day-1 [most fall between -10 to +10] C5 moulting potential: Mean C5 abundance 2500 individuals m-3 (Incze pump samples: April 1997, May 1997, June 1995) Stage duration in GB conditions: 5 days (McLaren et al., 1989) Implied moulting flux of 500 individuals m-3 day-1

  9. Are the inverse solutions ecologically realistic? Predation potential: Model predicted rates of 3-10% day-1 Bollens et al. specific rates of predation on C. finmarchicus and Pseudocalanus spp. copepodites based on observed predator abundance and feeding rates http://userwww.sfsu.edu/~bioocean/research/gbpredation/gbpredation1.html

  10. Caveats to interpretation of these solutions Physics -- assumes perfect knowledge of the circulation -- 2-D transport (no vertical shear) Biology -- density dependence vs. “geographic” formulation -- multistage models, behavior, etc. Observational limitations -- only adults sampled -- upper 40m

  11. C. finmarchicus climatology: Globec Broadscale surveys 1995-1999 Jan Feb Mar Apr May Jun N3 N4 N5 Durbin et al. http://globec.gso.uri.edu/ N6 C1 C2 C3 C4 Log(abundance) C5 C6 Time

  12. C. finmarchicus model X. Li et al. Fi: molting flux Fi(T,Chl) computed (Campbell et al. 2001) R: sources of N3 Inferred (monthly) μi: mortality Inferred (monthly) Ci off-bank Inferred (initial conditions) N3 N4 N5 N6 C1 C2 C3 C4 C5 C6 μN4 μN5 μN6 μC1 μC2 μC3 μC4 μC5 μC6 R

  13. Inferred off-bank initial conditions N3 N4 N5 N6 C1 C2 C3 C4 C5 C6

  14. C. finmarchicus solution: January- June

  15. Inferred Mortality Jan-Feb Feb-Mar Mar-Apr Apr-May May-Jun N3 N4 N5 N6 C1 C2 C3 C4 C5 C6

  16. Spatially averaged mortality rate:seasonal variation

  17. Spatially averaged mortality rate:January-June average

  18. Term-by-term analysis Transport terms: large magnitude, but net effect is small Primary balance: tendency/molting/mortality

  19. Spatially averaged mortality rate Mortality (d-1) Black: central case Gray: off-bank sources=0 (including ICs) Stage

  20. Biological control of the vernal population increase of C. finmarchicus on Georges Bank Advective delivery Advective delivery Georges Bank Georges Bank Advective loss Advective loss × only slightly smaller than

  21. Eddy-driven sources and sinks of nutrients in the upper ocean:results of a 0.1° resolution model of the North Atlantic McGillicuddy, D.J., Anderson, L.A., Doney, S.C. and M.E. Maltrud National Science Foundation NCAR: Scientific Computing Division

  22. New Production in the Open Ocean

  23. An eddy-resolving nutrient transport model Euphotic Zone: NP=NP(I,NO3,T) Aphotic Zone: Relaxation to clim. NO3(σT)

  24. Simulated Annual New Production OWSI NABE BATS EUMELI

  25. Annual New ProductionTerm Balances New Prod Conv + Diff Vertical advection Horizontal advection Total Mean Eddy

  26. New Production at BATS:Three Models, Three Different Nutrient Transport Pathways Observed Annual New Production = 0.5 mol N m-2 yr-1

  27. Coarse (1.6º) Eddy-resolving (0.1º) Sea Surface Temperature log (New Production)

  28. Toward a basin-scale model of C. finmarchicus Planque et al. (1997)

  29. END

  30. References McGillicuddy, D.J., Lynch, D.R., Moore, A.M., Gentleman, W.C., Davis, C.S., and C.J. Meise, 1998b. An adjoint data assimilation approach to diagnosis of physical and biological controls on Pseudocalanus spp. in the Gulf of Maine - Georges Bank region . Fisheries Oceanography, 7(3/4), 205-218. McGillicuddy, D.J. and A. Bucklin, 2002. Intermingling of two Pseudocalanus species on Georges Bank . Journal of Marine Research, 60, 583-604. McGillicuddy, D.J., Anderson, L.A., Doney, S.C., and M.E. Maltrud, 2003. Eddy-driven sources and sinks of nutrients in the upper ocean: results from a 0.1 degree resolution model of the North Atlantic. Global Biogeochemical Cycles, 17(2), 1035, doi:10.1029/2002GB001987. See http://www.whoi.edu/people/mcgillic “publications” link for more information

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