Transport biogeochemical cycles, modeling

This chapter focuses on types of models used to describe the functioning of biogeochemical cycles, i.e., reservoir or box models. Certain fundamental concepts are introduced and some examples are given of applications to biogeochemical cycles. Further examples can be found in the chapters devoted to the various cycles. The chapter also contains a brief discussion of the nature and mathematical description of exchange and transport processes that occur in the oceans and in the atmosphere. This chapter assumes familiarity with the definitions and basic concepts listed in Section 1.5 of the introduction such as reservoir, flux, cycle, etc. 

Hunt, E. R. Jr., Piper, S. C., Nemani, R., Keeling, C. D., Otto, R. D. and Running, S. W. (1996). Global net carbon exchange and intra-annual atmospheric CO2 concentrations predicted by an ecosystem process model and three-dimensional atmospheric transport model. Global Biogeochem. Cycles 10, 431-456. 

Baisden WT, Amundson R, Brenner DL, Cook AC, Kendall C, Harden JW (2002) A multi-isotope C and N modeling analysis of soil organic matter turnover and transport as a function of soil depth in a California annual grassland soil chronosequence. Global Biogeochem Cycles 16 1135. doi 10.1029/2001GB001823... 

Bouwman, A. F., and J. A. Taylor, Testing High-Resolution Nitrous Oxide Emission Estimates against Observations Using an Atmospheric Transport Model, Global Biogeochem. Cycles, 10, 307-318 (1996). 

In an attempt to understand the factors that determine the feedbacks from the global nature-society system of the cycles of carbon and other chemicals, we construct a hierarchy of model units to parameterize all the known physical and biogeochemical processes that are responsible for the transport of various substances. We substantiate these units by means of partial models which estimate the balance between relationships at the boundaries of different media. The correlations between biogeochemical cycles and the many activities of human society are the basic objectives of this book. 

Najjar, R., Sarmiento,. L., and Toggweder,. R. (1992). Downward transport and fate of organic matter in the Oceans Simulations with a general circulation model. Global Biogeochem. Cycles 6, 45—76. 

Sarmiento J. L., Monfray P., Maier-Reimer E., Aumont O., Murnane R. J., and Orr J. C. (2000) Sea-air CO2 fluxes and carbon transport a comparison of three ocean general circulation models. Global Biogeochem. Cycles 14, 1267-1281. 

A great future challenge for modeling the Baltic Sea ecosystem is related to the task of conceptual and numerical ecosystem model formulation. Before a numerical ecosystem model can be implemented and simulations are carried out, a conceptual view on the ecosystem must be developed and formulated. This includes the determination of the major links in the biogeochemical cycles, identification of the leading players in these cycles, and to find estimates for their activity in the transport and transformation of matter. This requires accomplishing the difficult task of a far-reaching simplification of a complex conceptual ecosystem model, the formulation as mathematical equations and the numerical implementation of suitable solution methods. Little is known about many model parameters. 

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