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The carbon budget of Mono Lake
Author(s) -
Oxburgh Rachel,
Broecker Wallace S.,
Wanninkhof Richard H.
Publication year - 1991
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 - 10.1029/91gb02475
Subject(s) - radiocarbon dating , salinity , dissolved organic carbon , carbonate , total inorganic carbon , carbon dioxide , carbon fibers , hydrology (agriculture) , geology , environmental science , carbon cycle , mineralogy , oceanography , chemistry , paleontology , ecology , materials science , geotechnical engineering , organic chemistry , ecosystem , composite number , composite material , biology
Radiocarbon measurements suggest that 14 C‐free carbon enters from beneath Mono Lake at a rate of about 1 mol/m 2 /yr. An input of this magnitude should be manifested in the inorganic carbon budget of the lake and with this in mind we have devised a model to reconstruct the evolution of the partial pressure of CO 2 (pCO 2 ) over the past 150 years. This encompasses a period (1945 to present) during which major diversions of source waters via the Los Angeles aqueduct have been in effect, significantly increasing the salinity of the lake and hence its pCO 2 . The model has been constrained by experimental characterization of the carbonate chemistry of the lake water, by the temperature dependence of pCO 2 for the lake water, and by pCO 2 measurements made on the lake water in 1966, 1969,1981, and 1989. Our calculations suggest that prior to 1945 the pCO 2 of Mono Lake water was about 1.3 times the atmospheric value. To produce this excess, an input of CO 2 of about 3.3 mol/m 2 /yr is required. Volcanic activity beneath the lake is a probable source of this input.