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Role of dissolved organic matter in the marine biogeochemical cycle: Studies using an ocean biogeochemical general circulation model
Author(s) -
Yamanaka Yasuhiro,
Tajika Eiichi
Publication year - 1997
Publication title -
global biogeochemical cycles
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.512
H-Index - 187
eISSN - 1944-9224
pISSN - 0886-6236
DOI - 10.1029/97gb02301
Subject(s) - biogeochemical cycle , dissolved organic carbon , environmental science , geochemical cycle , carbon cycle , organic matter , new production , biogeochemistry , oceanography , refractory (planetary science) , environmental chemistry , chemistry , geology , phytoplankton , nutrient , ecosystem , ecology , materials science , biology , organic chemistry , composite material
A biogeochemical general circulation model which includes production and consumption processes of dissolved organic matter (DOM) is developed. The semilabile and the refractory DOM are taken into account. The vertical distribution of the dissolved organic carbon (DOC) concentration and the Δ 14 C value obtained in our model compares well with the recent observations. It is found that the double DOC maximum zone (DDMZ) extends in the east‐west direction in the equatorial Pacific. Case studies, which change the decay time and production ratio constant, show that the horizontal distribution of DOC in the surface layer can be reproduced only when the decay time of the semilabile DOM is about half a year. The semilabile DOM exists only above a depth of 400 m, and its vertical and horizontal transport plays an important role in the marine biogeochemical cycle in the surface layer. However, below that depth, only the inert refractory DOM exists, and the role of the refractory DOM in the biogeochemical cycle is not important. The global export production due to the particulate organic matter (POM) and DOM at a depth of 100 m is estimated to be about 8 Gt C/yr and about 3 Gt C/yr, respectively. The vertical transport below 400 m is due almost entirely to POM.