HR: 14:40h
AN: OS23F-05    [Abstracts]
TI: CO2/CLIVAR Repeat Hydrography Program: Decadal Changes in the Inorganic Carbon Cycle in the North Atlantic Ocean CO2/CLIVAR Repeat Hydrography Program: Decadal Changes in the Inorganic Carbon Cycle in the North Atlantic Ocean
AU: Wanninkhof, R
EM: Rik.Wanninkhof@noaa.gov
AF: Ocean Chemistry Division, NOAA/AOML, 4301 Rickenbacker Causeway, Miami, fl 33149 United States
AU: * Sabine, C L
EM: Chris.Sabine@noaa.gov
AF: NOAA/PMEL, 7600 Sand Point Way NE, Seattle, WA 98115 United States
AU: Gruber, N
EM: ngruber@igpp.ucla.edu
AF: UCLA, IGPP & Dept. of Atmospheric and Oceanic Sciences, Los Angeles, ca 90095-4996 United States
AU: Feely, R A
EM: Richard.A.Feely@noaa.gov
AF: NOAA/PMEL, 7600 Sand Point Way NE, Seattle, WA 98115 United States
AU: Bullister, J L
EM: John.L.Bullister@noaa.gov
AF: NOAA/PMEL, 7600 Sand Point Way NE, Seattle, WA 98115 United States
AU: Johnson, G C
EM: gregory.c.johnson@noaa.gov
AF: NOAA/PMEL, 7600 Sand Point Way NE, Seattle, WA 98115 United States
AU: Zhang, J
EM: Jia-Zhong.Zhang@noaa.gov
AF: Ocean Chemistry Division, NOAA/AOML, 4301 Rickenbacker Causeway, Miami, fl 33149 United States
AU: Millero, F
EM: millero@rsmas.miami.edu
AF: RSMAS, MAC, U. Miami, 4600 Rickenbacker Causeway, Miami, fl 33149 United States
AU: Dickson, A G
EM: adickson@ucsd.edu
AF: Scripps Institution of Oceanography, 9500 Gilman Drive, La Jolla, ca 92093
AU: Swift, J H
EM: jswift@ucsd.edu
AF: Scripps Institution of Oceanography, 9500 Gilman Drive, La Jolla, ca 92093
AB: During the summer and fall of 2003 the first three cruises of the CO2/CLIVAR Repeat Hydrography Program took place in the North Atlantic along the meridional lines A22 (65?W), A20 (50?W), and A16N (20?W). The primary objectives of the cruises were to quantify changes in ventilation and carbon inventories, including anthropogenic CO2, (Canthro) in the North Atlantic basin on a decadal timescale. The decadal evaluation is performed by comparison with the WOCE/WHP A20 and A22 cruises occupied in July/August 1997 and the NOAA/OACES cruise along 20 ?W occupied during July/August 1993. The most striking aspects of the comparisons are the significant changes in apparent oxygen utilization (AOU) and dissolved inorganic carbon (DIC) at mid-depth between 200 and 1000 m. The increases in AOU are due to a either changes in organic matter remineralization rate or changes in ventilation or a combination thereof. The locations of large AOU changes correspond to regions of large DIC increases as expected from remineralization processes. These observed changes challenge some of the assumptions used to separate the Canthro increase from natural CO2 changes in the ocean. Changes in DIC and Canthro are determined for the western basin of the North Atlantic using different calculation methods to illustrate the sensitivity of the methods to determine Canthro to natural changes in background DIC. The observations will be put in context with recent published results suggesting that the uptake of CO2 in the North Atlantic is greater than expected from the current atmospheric CO2 perturbation.
DE: 4215 Climate and interannual variability (3309)
DE: 1635 Oceans (4203)
DE: 0330 Geochemical cycles
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting