High-frequency measurements of total CO2:: Method development and first oceanographic observations

被引:74
作者
Bandstra, L
Hales, B [1 ]
Takahashi, T
机构
[1] Oregon State Univ, Coll Ocean & Atmospher Sci, Corvallis, OR 97331 USA
[2] Lamont Doherty Earth Observ, Palisades, NY 10964 USA
基金
美国国家科学基金会;
关键词
D O I
10.1016/j.marchem.2005.10.009
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
We developed a system to accurately, precisely, and rapidly measure total dissolved carbon dioxide (T-CO2) in a continuously flowing seawater stream. The system is based on a gas-permeable membrane contactor, through which CO2 evolved from an acidified seawater stream is continuously and quantitatively stripped by a flowing gas stream. The CO2 content of this strip-gas stream, which is proportional to the TCO2 of the seawater stream via a simple mass balance, is then analyzed using a non-dispersive infra-red (NDIR) gas analyzer. Laboratory results have shown that the system has an e-folding response time of 6 s and is able to resolve changes in signal with better than +/- 0.1% precision. Independent coulometric analyses of check samples collected in the field, analyses of internal check samples, and analyses of certified reference materials have shown the accuracy of the system to be reliable to +/- 0.1%. Coupled with the Lamont Pumping SeaSoar system, the T-CO2 system has yielded high spatial resolution distributions of T-CO2 across the New England shelfbreak front. These T-CO2 data, in conjunction with collocated PCO, measurements of similar resolution, allowed us to calculate total alkalinity (TALK) at the high spatial resolution of the T-CO2 and P-CO2 measurements. While we cannot rule out or fully constrain the effects of mixing or variations in fresh water input, distributions of TALK relative to T-CO2 in the context of several independent lines of reasoning, indicated that biogenic calcium carbonate production may play an important role in shaping the TALK and T-CO2 distributions in waters across the New England shelfbreak front. (c) 2005 Elsevier B.V. All rights reserved.
引用
收藏
页码:24 / 38
页数:15
相关论文
共 27 条
[1]   BIOLOGICAL AND OPTICAL-PROPERTIES OF MESOSCALE COCCOLITHOPHORE BLOOMS IN THE GULF OF MAINE [J].
BALCH, WM ;
HOLLIGAN, PM ;
ACKLESON, SG ;
VOSS, KJ .
LIMNOLOGY AND OCEANOGRAPHY, 1991, 36 (04) :629-643
[2]   The 1991 coccolithophore bloom in the central North Atlantic .1. Optical properties and factors affecting their distribution [J].
Balch, WM ;
Kilpatrick, KA ;
Trees, CC .
LIMNOLOGY AND OCEANOGRAPHY, 1996, 41 (08) :1669-1683
[3]   The 1991 coccolithophore bloom in the central North Atlantic .1. Relating optics to coccolith concentration [J].
Balch, WM ;
Kilpatrick, KA ;
Holligan, P ;
Harbour, D ;
Fernandez, E .
LIMNOLOGY AND OCEANOGRAPHY, 1996, 41 (08) :1684-1696
[4]   Secondary circulation associated with a shelfbreak front [J].
Barth, JA ;
Bogucki, D ;
Pierce, SD ;
Kosro, PM .
GEOPHYSICAL RESEARCH LETTERS, 1998, 25 (15) :2761-2764
[5]  
BVERNER EK, 1996, GLOBAL ENV WATER AIR
[6]   PRIMARY PRODUCTION AT 47-DEGREES-N AND 20-DEGREES-W IN THE NORTH-ATLANTIC OCEAN - A COMPARISON BETWEEN THE C-14 INCUBATION METHOD AND THE MIXED LAYER CARBON BUDGET [J].
CHIPMAN, DW ;
MARRA, J ;
TAKAHASHI, T .
DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY, 1993, 40 (1-2) :151-169
[7]  
COVERT P, 2003, OCEAN SCI M S, V84
[8]  
Dickson A.G., 1994, DOE handbook of methods for the analysis of the various parameters of the carbon dioxide system in seawater
[9]   PH SCALES AND PROTON-TRANSFER REACTIONS IN SALINE MEDIA SUCH AS SEA-WATER [J].
DICKSON, AG .
GEOCHIMICA ET COSMOCHIMICA ACTA, 1984, 48 (11) :2299-2308
[10]   THE MEASUREMENT OF SEA-WATER PH [J].
DICKSON, AG .
MARINE CHEMISTRY, 1993, 44 (2-4) :131-142