HR: 08:25h
AN: B41F-02    [Abstracts]
TI: Land and ocean biospheres coupling inferred from observations and modelling - implications for future precidtions
AU: * Patra, P K
EM: prabir@jamstec.go.jp
AF: FRCGC/JAMSTEC, 3173-25 Showa-machi, Yokomama, 2360001, Japan
AB: Remote sensing instruments (e.g., SeaWiFS) have provided about a decade-long continuous record of terrestrial biospheric parameters and surface ocean biology. Here I explore the coupled mode change over the land and ocean, using the SeaWiFS seasonal and monthly average biosphere data for the period of September 1997 - August 2006 (http://oceancolor.gsfc.nasa.gov). Relatively strong short-term negative NDVI tendencies are observed over large parts of Africa, the Gulf, Asia, Australia, and southern South America between first two and last two years of SeaWiFS measurements. In contrast Chl-a increases during the same period are predominantly observed in the Indian Ocean (IO), East Pacific (EP), West Pacific (WP), and in patches over the Southern Ocean. Important to note here that the regions of increased (decreased) Chl-a are generally adjacent to the land regions with negative (positive) NDVI tendencies. To reveal the coupled mode variability in NDVI and Chl-a Principal component analysis (PCA) is performed on the SeaWiFS biosphere dataset. PCA of NDVI and Chl-a jointly suggests existence of stationary/dipole modes of variability between several neighbouring land-ocean regions. Other satellite and analyzed products, e.g., SST, precipitation (PCP), absorbing aerosols suggest that the observed land-ocean biospheres are coupled beyond that can be explained by purely dynamical mechanisms. It is proposed here that not only the responses of biological observations to physical parameters, e.g., SST and Chl-a or NDVI and PCP, but also the biogeochemical coupling through the atmospheric constituents (e.g., aerosols from land) would be needed in fully interacting mode to explain SeaWiFS-like observations. Note the present coupled models do not treat the emission, transport and deposition of atmospheric constituents interactively in coupled carbon cycle simulations Some of these mechanisms are discussed in a recent publication (P. K. Patra, SOLA, 3, 77-80, 2007). I will use the modelling results using biogeochemical elemental cycling and atmospheric-CO2 inverse modelling (Patra et al., J. Geophys. Res., 112, G02012, 2007) for discussing implications of the observation based land-ocean coupled system for future projections of carbon exchange between the earth's surface and the atmosphere.
DE: 0315 Biosphere/atmosphere interactions (0426, 1610)
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0428 Carbon cycling (4806)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting