Particle flux experiments with HAMOCC and LSG or MPIOM

1. Particle flux experiments with HAMOCC and LSG or MPIOM • E.Maier-Reimer, C.Heinze, I.Kriest, J.Segschneider, K.Six, M.Howard, J.Tjiputra, A.Winguth

2. 3Box models eg Harvardton Bear 20 Box eg Pandora 2.5 dimensional eg Wright/Stocker Genie LSG GCM coarse (~200 km) GCMHR (<30 km) Hierarchy of models Onset of dynamics Understanding lacks Schlitzer

3. LSG vs Genie • Both aiming essentially geostrophy • fxU=-gradP • -rU (Genie, „Rayleigh“ friction) • -U t (LSG, damping of gravity waves by time discretization). Definitely more arithmetics for given resolution. • Structures similar but Genie more sluggish

4. HAMOCC versions • HAMOCC2: annual mean circulation, convection parameterized as diffusion, production from restoring surface P to 0 with 3 months (many Heinze et al. Papers 1989 and later). • HAMOCC3: Seasonal cycle EMR 1993 • HAMOCC4: explicit plankton dynamics and multicomponent sediment Six,EMR 1996 • HAMOCC5 competing N,P,Fe, denitrification and N-fixation Aumont, Wetzel 2002,05

6. Natural Radiocarbon GOSAC

9. Prerequisites for modeling • Realistic circulation • Realistic boundary conditions and forcing • Realistic process formulation • What happens if one or more not? • It is not foreseeable

10. 2cm/a 15cm/a Spreading rate of midoceanic rideges,source for δ3He

11. δ3He from GOSAC study (Orr et al.)

12. Multitracer approach is a must! • Unfortunately our funding agency didn‘t perfectly agree

17. Dpm/100kg

20. On remineralization profiles • (wP)z= -rP  exponential profile • Suess, Martin : Fp ~ z-α (0.8< α<1) • Fz = - (r/w)F • If somehow (r/w)=a/z, F=F0z -a • How to generate a/z? • Temperature, particle aggregation with/out dust particles, mineral ballast loading

24. Validation of dust input through simulation of dissolved Al Gehlen, Heinze, Maier-Reimer and Measures, 2003, Global Biogeochem. Cycles

25. 3 km phosphorus from WOA

28. POC fluxes for different formulations

31. Assimilation of data • Look at data and tune parameters. • Have all model feedbacks in mind • Create the adjoint code (more by Thomas) • Winguth (1996) took δ13C for determination of glacial climate forcing with HAMOCC3 • Tjiputra (2006) did it for chlorophyll and nitrate for the full plankton model

33. Chlorophyll (mg-3) for the first guess integration (4 seasons)

34. Chlorophyll (mg m-3 )after optimization for the 4 seasons

35. Particle aggregation (Kriest, Evans) • θ =aggregate diameter • ε =slope of size distribution in log diagram • size spectrum P(θ)= Aθ-ε • Number of aggregates =A int θ-ε dθ • W( θ)= B θη

36. Vertical distribution of POC southern ocean global

37. Vertical distribution of POC North Atlantic Equatorial Pacific

38. d13C profiles atlantic/pacific NADW signature DEPTH [m] North Pacific Atlantic off Recife

39. D14C profiles t1/2=5700a ‘new’ deep water oldest water intermediate age (300a) old water (1000a) MPIOM/HAMOCC5 GR15L40

40. global Export across 90 m vs primary production

41. Reg. Prod (no O) New prod. from NO3 (O-isotopes) N2 algae NH3 algae Remineralization Release of NH3 locally NO3 consumption with isotopic fractionation Nitrate depleted vs P, enriched in heavy isotopes oxidation

42. Depth/m

44. Thanks

47. d13c profile 12C evaporates more easily and is preferred by plankton during photosynthesis (20o/oo) remineralisation of organic matter inflow of deep water originating from low SST regions (evaporative fractionation is temperature dependent, with higher 13C in colder water) DEPTH [m] 13C profile in the North Pacific from GR15L40 MPIOM/HAMOCC5 4 years after initialisation from PO4 ? (model 13C not yet in equilibrium)