MODELLING THE FEEDBACKS BETWEEN PHYTOPLANKTON AND GLOBAL OCEAN PHYSICS 1Max-Planck-Institut fr Biogeochemie, Jena, Germany.2University of East Anglia, Norwich, United Kingdom.Manfredi Manizza1,2, C. Le Qur 1, A. J. Watson2,E. Buitenhuis1

PHYTOPLANKTON-LIGHT-HEAT INTERACTION

FROM TROPICAL TO GLOBAL 1) An OGCM (OPA) on global configuration: 0.5 - 1.5 x 2.0 (Lat x Lon) 1.5 order TKE Model. Gent-McWilliams eddy-mixing.2) An ocean biogeochemistry model (Dynamic Green Ocean Model) : Diatoms and Coccolithophores and Nanophytoplankton. Micro and Mesozooplankton. Co-limitation of light,P, Si and Fe.3) A Sea-Ice model (LIM) Tropical Studies: Nakamoto et al. (2000, 2001); Murtugudde et al. (2002) OGCM + Satellite derived Chlorophyll Off-line forcing NO FEEDBACKS !!Ocean Surface

INCLUDING THE BIOLOGYK() = LIGHT EXTINCTION COEFFICIENTREDBLUE/GREENINFRAREDPaulson & Simpson Model (JPO,1977)Morel Model (JGR,1988)[Chl]tot = [Chl]diatom + [Chl]cocco + [Chl]nano

Monthly MaximumTHE MODELLED BIO-FORCING (mg m-3)Monthly AverageSURFACE [Chl]

PENETRATION DEPTH (Zpen)IoZpenZpen = (ez I (z) dz)/Io Average(m)Zpen Visible Light = 23 m

TROPICS

Average SEA SURFACE TEMPERATURE C TEMPERATURE C

MLD & u(surf)Average(m)

TROPICS TO SUB-TROPICS

TROPICS/SUBTROPICS INTERACTION EquatorSubtropicsSubtropics+PO4-MLD+u+TPP

TOTALPRIMARYPRODUCTIONgC m-2 yr-1

MONTHLY AVERAGE DEPTH

HIGH LATITUDES

SEA SURFACE TEMPERATURE Monthly Maximum C

EFFECTS ON SEA-ICE (AVERAGE) %ICEN = -0.17 * [Chl]surf %ICES = -1.3 * [Chl]surf%(Ice fraction)Sea-iceOceanSunPhytoplankton

GLOBAL

ECOSYSTEM RESPONSE Total Chl (mg m-3)Diatoms (%)Coccolithophores (%)Nanophyto (%) AVERAGE

IMPACT ON OCEAN CARBON CYCLE

CONCLUSIONS Different and Regional Modifications: SST, MLD, CURRENTS, SEA-ICE. OCEAN PHYSICS ECOSYSTEM & OCEAN BIOGEOCHEMISTRY OCEAN CARBON CYCLE. Global OBGCM Tropics and Interaction Tropics/Subtropics & High Latitudes. Phytoplankton presence affects light and heat penetration in the ocean.

Dynamic Green Ocean Model(Buitenhuis et al.,in prep.)

In the Community Land Model, vegetation is not represented as biomes (e.g., savanna) but rather as patches of plant functional types (e.g., grasses, trees).