NETCARE: B2-4c Parameterizing Climate-DMS Feedbacks Modelling the marine source and exchange at interfaces Nadja Steiner, Institute of Ocean Sciences, DFO, Sidney & CCCma, EC Hakase Hayashida, School of Earth and Ocean Sciences, UVIC, Victoria

ASCM OSCM Fluxes SST NCEP Reanalysis/ Other forcing Initialisation Includes: Ecosystem model: N 2 P 2 Z 2 D, Inorganic Carbon cycle: DIC,Alk, O2,N2, Si cycles Marine DMS cycle Steiner & Denman 2008 ASCM: Atmospheric Single Column Model extract from CCCma global GCM OSCM: 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 OSP S: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:◊ Steiner et al. 2012

Phytoplankton composition from pigment analysis (HPLC) No downward trend in August! DMSP producer Dinoflagellates absent in June

? DMSP d NiNi NaNa Z 2 (t) DMSO+Sp DMS D Z1Z1 DMSP p PsPs Sinking Aggregates Detritus Entrainment +Mixing Photolysis Bact. cons. enzym. cleavage Air-Sea/Air-Ice exchange PlPl Spl Si P Si cleavage Bact. cons. PaPa DMSPp DMS ? 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 New

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A B 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 photometri c detector. DMS analysis: “Purge and trap”

Gas exchange velocities k ex

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 NO 3 - content (Bouillon and Miller 2004). Calculate photolysis as f(UV): Based on photolysis rates, DMS, UVA/B from SERIES we obtain: photo= c A x UVA(z) + c B x UVB(z) (c A,B = 0.026; 2.6 d -1 (Wm -2 ) -1 ) ‏