physical-biological interactions: regional to basin scales
DESCRIPTION
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 - PowerPoint PPT PresentationTRANSCRIPT
Physical-biological interactions:Physical-biological interactions:regional to basin scalesregional 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
General circulation during the stratified seasonGeneral circulation during the stratified seasonBeardsley et al. (1997)
A finite-element model A finite-element model of the Gulf of Maine / of the Gulf of Maine / Georges Bank region Georges Bank region (Lynch et al., 1996)(Lynch et al., 1996)
PseudocalanusPseudocalanus spp. spp. MARMAP 1977-1987MARMAP 1977-1987
Concentration (# m-3)
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
A first attempt to A first attempt to simulate the simulate the
observed observed PseudocalanusPseudocalanus spp. spp.
distributions…distributions…
P. moultoni
P. newmani
1997 Broadscale Survey Data1997 Broadscale Survey Data
Species-specific PCR(Bucklin et al., 2001)
Observations:P. Moultoni
Models
Observations:P. newmani
Are the inverse solutions ecologically realistic?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
Are the inverse solutions ecologically realistic?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 predatorabundance and feeding rates
http://userwww.sfsu.edu/~bioocean/research/gbpredation/gbpredation1.html
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
Caveats to interpretation of these solutionsCaveats to interpretation of these solutions
C. finmarchicusC. finmarchicus climatology: climatology:
Globec Broadscale Globec Broadscale surveys 1995-1999surveys 1995-1999
N3
N4
N5
N6
C6
C5
C4
C3
C2
C1
Jan Feb Mar Apr May Jun
Time
Log
(abu
ndan
ce)
Durbin et al.http://globec.gso.uri.edu/
1 1 1( ) ( )(1 )ii i i i i i i i
Cv C K C R F F C
t
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
R μN4 μN5 μN6 μC1 μC2 μC3 μC4 μC5 μC6
C. finmarchicus modelX. Li et al.
Inferred off-bank initial conditions
N3 N4 N5 N6 C1
C2 C3 C4 C5 C6
C. finmarchicus solution: January- June
Inferred Mortality
N3
N4
N5
N6
C6
C5
C4
C3
C2
C1
Jan-Feb Feb-Mar Mar-Apr Apr-May May-Jun
Spatially averaged mortality rate:seasonal variation
Spatially averaged mortality rate:January-June average
Term-by-term analysis
Transport terms: large magnitude, but net effect is smallPrimary balance: tendency/molting/mortality
Spatially averaged mortality rateSpatially averaged mortality rate
Black: central caseGray: off-bank sources=0 (including ICs)
Mor
tali
ty (
d-1)
Stage
Biological control of the vernal population increase of C. finmarchicus on Georges Bank
1i
i i i i
CF F C
t
1 ˆii i i i
CF F C
t
iˆi only slightly smaller than
Advectivedelivery
Advectiveloss
Georges Bank
Advectivedelivery
Advectiveloss
Georges Bank×
National Science FoundationNCAR: Scientific Computing Division
Eddy-driven sources and sinks of nutrients in the upper ocean:Eddy-driven sources and sinks of nutrients in the upper ocean:results of a 0.1results of a 0.1° resolution model of the North Atlantic° resolution model of the North Atlantic
McGillicuddy, D.J., Anderson, L.A., Doney, S.C. and M.E. Maltrud
2222 OOCHOHCO
tonPhytoplank
4443 SiOH , PO , NO
Nutrients
Fish) nZooplankto(
0I
0I 1%
New Production in theNew Production in theOpen OceanOpen Ocean
12yrm N mol 0.5
An eddy-resolving nutrient transport modelAn eddy-resolving nutrient transport model
Euphotic Zone: NP=NP(I,NO3,T)Aphotic Zone: Relaxation to clim.
NO3(σT)
Simulated Annual New ProductionSimulated Annual New Production
BATS EUMELI
NABE
OWSI
Verticaladvection
Horizontaladvection
New Prod Conv + Diff
Total Mean Eddy
Annual Annual New New
ProductionProductionTerm Term
BalancesBalances
Observed Annual New Production = 0.5 mol N m-2 yr-1
New Production at BATS:New Production at BATS:Three Models, Three Different Nutrient Transport Pathways
Coarse (1.6º) Eddy-resolving (0.1º)
Sea SurfaceTemperature
log (NewProduction)
Toward a basin-scale model of Toward a basin-scale model of C. finmarchicusC. finmarchicus
Planque et al. (1997)
END
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