Sinking rates of particles measured from deployments in the Atlantic Ocean based on seasonal data


Autoria(s): Fischer, Gerhard; Karakas, Gökay
Cobertura

MEDIAN LATITUDE: -2.305827 * MEDIAN LONGITUDE: -24.708705 * SOUTH-BOUND LATITUDE: -62.250000 * WEST-BOUND LONGITUDE: -57.533300 * NORTH-BOUND LATITUDE: 21.300000 * EAST-BOUND LONGITUDE: 9.150000 * DATE/TIME START: 1983-01-01T00:00:00 * DATE/TIME END: 2002-01-01T00:00:00

Data(s)

12/05/2010

Resumo

The flux of materials to the deep sea is dominated by larger, organic-rich particles with sinking rates varying between a few meters and several hundred meters per day. Mineral ballast may regulate the transfer of organic matter and other components by determining the sinking rates, e.g. via particle density. We calculated particle sinking rates from mass flux patterns and alkenone measurements applying the results of sediment trap experiments from the Atlantic Ocean. We have indication for higher particle sinking rates in carbonate-dominated production systems when considering both regional and seasonal data. During a summer coccolithophorid bloom in the Cape Blanc coastal upwelling off Mauritania, particle sinking rates reached almost 570 m per day, most probably due the fast sedimentation of densely packed zooplankton fecal pellets, which transport high amounts of organic carbon associated with coccoliths to the deep ocean despite rather low production. During the recurring winter-spring blooms off NW Africa and in opal-rich production systems of the Southern Ocean, sinking rates of larger particles, most probably diatom aggregates, showed a tendency to lower values. However, there is no straightforward relationship between carbonate content and particle sinking rates. This could be due to the unknown composition of carbonate and/or the influence of particle size and shape on sinking rates. It also remains noticeable that the highest sinking rates occurred in dust-rich ocean regions off NW Africa, but this issue deserves further detailed field and laboratory investigations. We obtained increasing sinking rates with depth. By using a seven-compartment biogeochemical model, it was shown that the deep ocean organic carbon flux at a mesotrophic sediment trap site off Cape Blanc can be captured fairly well using seasonal variable particle sinking rates. Our model provides a total organic carbon flux of 0.29 Tg per year down to 3000 m off the NW African upwelling region between 5 and 35° N. Simple parameterisations of remineralisation and sinking rates in such models, however, limit their capability in reproducing the flux variation in the water column.

Formato

application/zip, 2 datasets

Identificador

https://doi.pangaea.de/10.1594/PANGAEA.738124

doi:10.1594/PANGAEA.738124

Idioma(s)

en

Publicador

PANGAEA

Direitos

CC-BY: Creative Commons Attribution 3.0 Unported

Access constraints: unrestricted

Fonte

Supplement to: Fischer, Gerhard; Karakas, Gökay (2009): Sinking rates and ballast composition of particles in the Atlantic Ocean: implications for the organic carbon fluxes to the deep ocean. Biogeosciences, 6, 85-102, doi:10.5194/bg-6-85-2009

Palavras-Chave #-; ANT-III/2; ANT-VII/5; Area; Area/locality; basis reference; BO3; BO3_trap; Bouvet Island; Calculated, see reference(s); Cape Blanc; CB1_trap; CB13; CB13_trap; CB2_trap; CB3_trap; CB4_trap; CB7; CB7_trap; Center for Marine Environmental Sciences; Coeff; Coefficient; correlation coefficient, 1-cup-s.; correlation coefficient, 2-cup-s.; correlation coefficient, no shift; correlation method; cup; cups; CV1-2_trap; CV2; CV2_trap; data points; Date/Time; DATE/TIME; Date/time end; deployment; Depth, bottom/max; Depth, top/min; Depth bot; Depth top; Duration; Duration, number of days; EA7; EA7_trap; EA8; EA8_trap; EA9; EA9_trap; East Equatorial Atlantic; Eastern equatorial Atlantic; Event; GBN3_trap; GBS5; GBS5_trap; GeoB2212-8; GeoB2908; KG1_trap; Label; Lag of peaks; Lag peak; Location; M12/1; M16/2; M22/1; M29/3; M6/6; M9/4; major peak method (Berelson, 2002); MARUM; mean s. r.; Meteor (1986); MOOR; Mooring; Mooring (long time); MOORY; Northwest Africa; PF3; Polar Front; Polarstern; PS06; PS14; Reference; Reference/source; Sample code/label; sampling interval days; sampling intervals; Season; season/month; Sinking rate; SR; Standard deviation; Std dev; Trap; TRAP; Trap, sediment; trap depth lower; trap depth upper; TRAPS; WA10; WA10_trap; WA11; WA11_trap; WA13; WA13_trap; WA14; WA14_trap; WA19; WA19_trap; WA4_trap; WA7_trap; WA8_trap; WA9; WA9_trap; Walvis Ridge, Southeast Atlantic Ocean; Western Atlantic; Western Equatorial Atlantic; WR2_trap
Tipo

Dataset