A seasonal three‐dimensional ecosystem model of nitrogen cycling in the North Atlantic Euphotic Zone

Jorge Louis Sarmiento, R. D. Slater, M. J.R. Fasham, H. W. Ducklow, J. R. Toggweiler, G. T. Evans

Research output: Contribution to journalArticlepeer-review

253 Scopus citations


A seven‐component upper ocean ecosystem model of nitrogen cycling calibrated with observations at Bermuda Station “S” has been coupled to a three‐dimensional seasonal general circulation model (GCM) of the North Atlantic ocean. The aim of this project is to improve our understanding of the role of upper ocean biological processes in controlling surface chemical distributions, and to develop approaches for assimilating large data sets relevant to this problem. A comparison of model predicted chlorophyll with satellite coastal zone color scanner observations shows that the ecosystem model is capable of responding realistically to a variety of physical forcing environments. Most of the discrepancies identified are due to problems with the GCM model. The new production predicted by the model is equivalent to 2 to 2.8 mol m−2 yr−1 of carbon uptake, or 8 to 12 GtC/yr on a global scale. The southern half of the subtropical gyre is the only major region of the model with almost complete surface nitrate removal (nitrate<0.1 mmol m−3). Despite this, almost the entire model is nitrate limited in the sense that any addition of nitrate supply would go predominantly into photosynthesis. The only exceptions are some coastal upwelling regions and the high latitudes during winter, where nitrate goes as high as ∼10 mmol m−3.

Original languageEnglish (US)
Pages (from-to)417-450
Number of pages34
JournalGlobal Biogeochemical Cycles
Issue number2
StatePublished - Jun 1993

All Science Journal Classification (ASJC) codes

  • Global and Planetary Change
  • Environmental Chemistry
  • General Environmental Science
  • Atmospheric Science


Dive into the research topics of 'A seasonal three‐dimensional ecosystem model of nitrogen cycling in the North Atlantic Euphotic Zone'. Together they form a unique fingerprint.

Cite this