Revisiting carbon flux through the ocean's twilight zone.
The oceanic biological pump drives sequestration of carbon dioxide in the deep sea via sinking particles. Rapid biological consumption and remineralization of carbon in the "twilight zone" (depths between the euphotic zone and 1000 meters) reduce the efficiency of sequestration. By using neutrally buoyant sediment traps to sample this chronically understudied realm, we measured a transfer efficiency of sinking particulate organic carbon between 150 and 500 meters of 20 and 50% at two contrasting sites. This large variability in transfer efficiency is poorly represented in biogeochemical models. If applied globally, this is equivalent to a difference in carbon sequestration of more than 3 petagrams of carbon per year.
Buesseler
Ken O
KO
Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA. kbuesseler@whoi.edu
Lamborg
Carl H
CH
Boyd
Philip W
PW
Lam
Phoebe J
PJ
Trull
Thomas W
TW
Bidigare
Robert R
RR
Bishop
James K B
JK
Casciotti
Karen L
KL
Dehairs
Frank
F
Elskens
Marc
M
Honda
Makio
M
Karl
David M
DM
Siegel
David A
DA
Silver
Mary W
MW
Steinberg
Deborah K
DK
Valdes
Jim
J
Van Mooy
Benjamin
B
Wilson
Stephanie
S
D000818:Animals; D002244:Carbon / Q000378:metabolism; D002245:Carbon Dioxide; D033342:Copepoda / Q000502:physiology; D017753:Ecosystem; D020387:Food Chain; D019015:Geologic Sediments / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D010140:Pacific Ocean; D010839:Phytoplankton / Q000502:physiology; D012623:Seawater / Q000737:chemistry; D015048:Zooplankton / Q000502:physiology
D002245:Carbon Dioxide; D002244:Carbon