Influence of the ITCZ and OMZ on the isotopic composition of suspended particulate matter in the western tropical North Atlantic

被引:1
|
作者
Pinango, Andres [1 ,2 ]
Azar, Elias [2 ,3 ]
Wallner-Kersanach, Monica [3 ]
Machado, Eunice da Costa [3 ]
Martins, Gabriela [2 ,3 ]
Peterle, Thayna [2 ]
de Rezende, Carlos Eduardo [4 ]
Baumgarten, Maria da Graca [3 ]
机构
[1] Univ Fed Rio Grande FURG, Lab Estudos Oceanos & Clima LEOC, Inst Oceanog, Ave Italia km 8 S-N,Campus Carreiros, BR-96203900 Rio Grande, RS, Brazil
[2] Univ Fed Rio Grande FURG, Programa Pos Grad Oceanol PPGO, Inst Oceanog, Ave Italia km 8 S-N,Campus Carreiros, BR-96203900 Rio Grande, RS, Brazil
[3] Univ Fed Rio Grande FURG, Lab Hidroquim, Inst Oceanog, Ave Italia km 8 S-N,Campus Carreiros, BR-96203900 Rio Grande, RS, Brazil
[4] Univ Estadual Norte Fluminense, Lab Ciencias Ambientais, UENF, BR-28013602 Campos Dos Goytacazes, RJ, Brazil
关键词
Suspended particulate matter; Intertropical convergence zone; Oxygen minimum zone; Carbon isotopes; Nitrogen isotopes; Carbon cycle; Atlantic Ocean; OXYGEN-MINIMUM ZONES; UPWELLING ANNUAL CYCLE; ORGANIC-CARBON FLUXES; NATURAL-ABUNDANCE; SOUTH ATLANTIC; STABLE CARBON; DATA PRODUCT; NITROGEN; OCEAN; WATER;
D O I
10.1016/j.jmarsys.2022.103803
中图分类号
P [天文学、地球科学];
学科分类号
07 ;
摘要
The tropical North Atlantic Ocean is a complex region where the intertropical convergence zone (ITCZ) and the oxygen minimum zone (OMZ) play important roles in the control of the physical and biogeochemical processes and affect the efficiency of the carbon pump. Changes in the composition of the particulate organic matter (POM) have been extensively studied in the eastern tropical North Atlantic and recent findings suggested less effective remineralization in the OMZ by comparison with well-oxygenated waters. However, dynamics of the POM in the western tropical North Atlantic, including the effect of the hypoxic condition on the isotopic signature of the POM, has been poorly understood. This study uses data collected in October 2018 during the PIRATA XVIII cruise (38 degrees W) to describe the biogeochemical variability and isotopic composition of suspended POM in the water column, with emphasis on the effect of the ITCZ and the OMZ on the POM. The ITCZ, located between 5 degrees N and 10 degrees N, was responsible for the low sea surface salinity and local upwelling, thus favoring the high biological productivity found in this band. Although a clear relation between delta C-13(POC) values and the ITCZ position was not found, low delta N-15(TPN) values (similar to 2 parts per thousand) and high silicate concentration observed on the surface between 4 degrees N-6 degrees N suggested that dust deposition and its associated enhancement of the diazotrophic activity may be important in the southernmost part of the ITCZ. Preferential remineralization of fractions rich in C-13 (proteins, carbohydrates) and nitrogen compounds resulted in low delta C-13(POC) and high C:N values observed at depth. However, these alterations were attenuated in the OMZ, suggesting that reduced remineralization expected in waters with low oxygen concentrations may also affect the isotopic POM signature. Additionally, the minimum delta N-15(TPN) value (similar to 1 parts per thousand) observed in the core of the OMZ confirms that, although microbial activity may be important in this region, nitrogen-loss processes are not predominant in the western tropical Atlantic.
引用
收藏
页数:12
相关论文
共 50 条
  • [1] THE COMPOSITION OF PARTICULATE ORGANIC MATTER IN THE WESTERN NORTH ATLANTIC
    MENZEL, DW
    RYTHER, JH
    LIMNOLOGY AND OCEANOGRAPHY, 1964, 9 (02) : 179 - 186
  • [2] Latitudinal distribution of nitrogen isotopic composition in suspended particulate organic matter in tropical/subtropical seas
    Zhang, Run
    Chen, Min
    Ma, Qiang
    Cao, Jianping
    Qiu, Yusheng
    ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES, 2011, 47 (04) : 489 - 497
  • [3] Signature of terrestrial influence on nitrogen isotopic composition of suspended particulate matter in the Bay of Bengal
    Kumar, S
    Ramesh, R
    Sheshshayee, MS
    Sardesai, S
    Patel, PP
    CURRENT SCIENCE, 2005, 88 (05): : 770 - 774
  • [4] Iron Isotopic Composition of Suspended Particulate Matter in Hongfeng Lake
    Zheng, Xiaodi
    Teng, Yanguo
    Song, Liuting
    WATER, 2019, 11 (02)
  • [5] STERENES IN SUSPENDED PARTICULATE MATTER IN THE EASTERN TROPICAL NORTH PACIFIC
    WAKEHAM, SG
    GAGOSIAN, RB
    FARRINGTON, JW
    CANUEL, EA
    NATURE, 1984, 308 (5962) : 840 - 843
  • [6] Influence of the Amazon River on the composition of particulate organic carbon in the western tropical Atlantic Ocean
    Utsumi, Giovanna S. A.
    He, Ding
    Berelson, William M.
    Castelao, Renato M.
    Yager, Patricia L.
    Medeiros, Patricia M.
    GEOCHIMICA ET COSMOCHIMICA ACTA, 2025, 389 : 84 - 99
  • [7] DISTRIBUTION AND COMPOSITION OF SUSPENDED MATTER IN WATERS OF THE NORTHEASTERN TROPICAL ATLANTIC
    BEZBORODOV, AA
    BURLAKOVA, ZP
    EREMEEVA, LV
    OKEANOLOGIYA, 1989, 29 (01): : 112 - 118
  • [8] Natural isotopic composition of nitrogen in suspended particulate matter in the Bay of Bengal
    Kumar, S
    Ramesh, R
    Bhosle, NB
    Sardesai, S
    Sheshshayee, MS
    BIOGEOSCIENCES, 2004, 1 (01) : 63 - 70
  • [9] PARTICLE-SIZE, LIGHT-SCATTERING AND COMPOSITION OF SUSPENDED PARTICULATE MATTER IN THE NORTH-ATLANTIC
    RICHARDSON, MJ
    DEEP-SEA RESEARCH PART A-OCEANOGRAPHIC RESEARCH PAPERS, 1987, 34 (08): : 1301 - 1329
  • [10] ELEMENTARY COMPOSITION OF SUSPENDED PARTICULATE MATTER IN THE NORTH-SEA
    NOLTING, RF
    EISMA, D
    NETHERLANDS JOURNAL OF SEA RESEARCH, 1988, 22 (03): : 219 - 236