NETCARE: B2-4c Parameterizing Climate-DMS

Feedbacks Modelling the marine source and exchange at interfaces

Nadja Steiner, Institute of Ocean Sciences, DFO, Sidney & CCCma, ECHakase Hayashida, School of Earth and Ocean Sciences, UVIC, Victoria

ASCM

OSCM

Fluxes

SST

NCEP Reanalysis/Other forcing

Initialisation

Includes:Ecosystem model: N

2P

2Z

2D,

Inorganic Carbon cycle: DIC,Alk,O2,N2, Si cycles

Marine DMS cycle

Steiner & Denman 2008

ASCM: Atmospheric Single Column Model extract from CCCma global GCMOSCM: Ocean SCM: General Ocean Turbulence Model (GOTM)

1-D Model development

Additions for NETCARE:Sea ice٭, Sea-ice algae

ecosystem with DMS Other organic aerosol sources

(surface films, bubble bursting)

DMSP and DMS cycles in the upper ocean (Gabric et al. 2002)

Boxes and processes currently represented in the model

Simulated DMS concentration (top 20m) at OSPS:N ratio, Fe limitation,S:N ratio seasonally varying to reflect the

absence of dinoflagellates in late spring

Wong et al 2004:Δ recent bottle: x MIMS:◊

2005-2006

2007-2008

Steiner et al. 2012

Steiner et al. 2012

Phytoplankton composition from pigment analysis (HPLC)

No downward trend in August!

DMSP producer

Dinoflagellates absent in June

?

DMSPd

Ni

Na

Z2(t)

DMSO+Sp

DMS

D

Z1

DMSPp

Ps

Sinking

AggregatesDetritusEntrainment

+Mixing

Photolysis

Bact. cons.

enzym. cleavage

Air-Sea/Air-Iceexchange

Pl Spl

Si

PSi

cleavage

Bact. cons.

PaDMSPpDMS

?

grazing

mortality

Photolysis, bact. conversion

Biol. conv.Sea Ice

Pelagic ecosystem

DMSPp

Fecal Pellets

University of Alberta North America Arctic (NAA) model (P. Myers): physical model only NEMO-LIM (so far => CICE) now installed with PISCES => Implement new ecosystem in coordination with CCCma - CanESM development

N3P2Z2D2, Alk, DIC, O2, N2O, DMS, sea-ice ecosystem (P, DMS)

Application in Regional Model

Thank you

Nadja.Steiner@dfo-mpo.gc.ca

AB

C

Sample (20ml) is loaded into the system (A).

DMS stripped from the water using UHP nitrogen at 100 ml/min (B) and absorbed into a Tenax-TA trap held at -170°C (C).

After 10 minutes sample is desorbed onto a Chromasorb 330 column using boiling water, and elutes onto a Gas Chromatograph with a flame photometric detector.

DMS analysis: “Purge and trap”

Gas exchange velocities kex

Photolysis• Mostly parameterized as function of PAR.

• Recent data show that photolysis is mainly caused by the UV range ( e.g. Bouillon et al., 2006): UVA: 70%, UVB:30%) and varies with NO3

-

content (Bouillon and Miller 2004).

• Calculate photolysis as f(UV): Based on photolysis rates, DMS, UVA/B from SERIES we obtain: photo= cA x UVA(z) + cB x UVB(z)

(cA,B = 0.026; 2.6 d-1 (Wm-2)-1)