Title Geochemistry of clathrate-derived methane in Arctic Ocean waters
Author Elliott, S.; Reagan, M.; Moridis, G.; Smith, P.C.
Author Affil Elliott, S., Los Alamos National Laboratory, Climate, Ocean and Sea Ice Modelling, Los Alamos, NM. Other: Lawrence Berkeley National Laboratory; Lawrence Livermore National Laboratory
Source Geophysical Research Letters, 37(12), Citation L12607. Publisher: American Geophysical Union, Washington, DC, United States. ISSN: 0094-8276
Publication Date 2010
Notes In English. 27 refs. GeoRef Acc. No: 310422
Index Terms clathrates; climatic change; hydrocarbons; oxygen; Arctic Ocean; aliphatic hydrocarbons; alkanes; anaerobic environment; biochemistry; biogenic processes; carbon dioxide; chemical reactions; climate change; methane; numerical models; nutrients; ocean circulation; organic compounds; oxidation; pH; sea water
Abstract Alterations to the composition of seawater are estimated for microbial oxidation of methane from large polar clathrate destabilizations, which may arise in the coming century. Gas fluxes are taken from porous flow models of warming Arctic sediment. Plume spread parameters are then used to bracket the volume of dilution. Consumption stoichiometries for the marine methanotrophs are based on growth efficiency and elemental/enzyme composition data. The nutritional demand implied by extra CH4 removal is compared with supply in various high latitude water masses. For emissions sized to fit the shelf break, reaction potential begins at one hundred micromolar and falls to order ten a thousand kilometers downstream. Oxygen loss and carbon dioxide production are sufficient respectively to hypoxify and acidify poorly ventilated basins. Nitrogen and the monooxygenase transition metals may be depleted in some locations as well. Deprivation is implied relative to existing ecosystems, along with dispersal of the excess dissolved gas. Physical uncertainties are inherent in the clathrate abundance, patch size, outflow buoyancy and mixing rate. Microbial ecology is even less defined but may involve nutrient recycling and anaerobic oxidizers.
URL http://hdl.handle.net/10.1029/2010GL043369
Publication Type journal article
Record ID 65007175