The Loop Current Circulation Over the MIS 9 to MIS 5 Based on Planktonic Foraminifera Assemblages From the Gulf of Mexico

IF 3.2 2区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Paleoceanography and Paleoclimatology Pub Date : 2023-03-01 DOI:10.1029/2022PA004568

E. Arellano‐Torres, Abril Amezcua‐Montiel, Arantza Casas‐Ortiz

{"title":"The Loop Current Circulation Over the MIS 9 to MIS 5 Based on Planktonic Foraminifera Assemblages From the Gulf of Mexico","authors":"E. Arellano‐Torres, Abril Amezcua‐Montiel, Arantza Casas‐Ortiz","doi":"10.1029/2022PA004568","DOIUrl":null,"url":null,"abstract":"The loop current (LC) in the Gulf of Mexico (GoM) is part of the western North Atlantic circulation. Recording its strength and slowdown variations can help us characterize the regional climate over the Late Pleistocene. To reconstruct the sea surface and the LC intensity in the eastern GoM, we study the distribution patterns of planktonic foraminifera in the core EN‐032‐18PC, spanning the end of Marine Isotope Stage (MIS) 9 to early MIS‐4. We reconstructed a sequence of paleoceanographic events based on stable isotopes (δ18O and δ13C) of the surface dweller Globigerinoides ruber and two faunal assemblages. The first assemblage explains most of the glacial and late interglacial periods, suggesting a subtropical environment with a deep thermocline and a reduced LC due to a moderate inflow of warm Caribbean waters. The second assemblage explains the warmest interglacial substages, dominated by tropical species, a shallow thermocline, and an extended LC, driven by summer insolation. Overall, surface ocean conditions led to more ecological successions and instability during the warmest interglacial substages than during glacial periods, as supported by the stable isotope records. Besides the GoM relationship to AMOC, as a regulator of heat transport to higher latitudes, we suggest that fluctuations in the LC rely on the migration of atmospheric circulation patterns and astronomical insolation forcing.","PeriodicalId":54239,"journal":{"name":"Paleoceanography and Paleoclimatology","volume":" ","pages":""},"PeriodicalIF":3.2000,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Paleoceanography and Paleoclimatology","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1029/2022PA004568","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}

引用次数: 1

Abstract

The loop current (LC) in the Gulf of Mexico (GoM) is part of the western North Atlantic circulation. Recording its strength and slowdown variations can help us characterize the regional climate over the Late Pleistocene. To reconstruct the sea surface and the LC intensity in the eastern GoM, we study the distribution patterns of planktonic foraminifera in the core EN‐032‐18PC, spanning the end of Marine Isotope Stage (MIS) 9 to early MIS‐4. We reconstructed a sequence of paleoceanographic events based on stable isotopes (δ18O and δ13C) of the surface dweller Globigerinoides ruber and two faunal assemblages. The first assemblage explains most of the glacial and late interglacial periods, suggesting a subtropical environment with a deep thermocline and a reduced LC due to a moderate inflow of warm Caribbean waters. The second assemblage explains the warmest interglacial substages, dominated by tropical species, a shallow thermocline, and an extended LC, driven by summer insolation. Overall, surface ocean conditions led to more ecological successions and instability during the warmest interglacial substages than during glacial periods, as supported by the stable isotope records. Besides the GoM relationship to AMOC, as a regulator of heat transport to higher latitudes, we suggest that fluctuations in the LC rely on the migration of atmospheric circulation patterns and astronomical insolation forcing.

查看原文本刊更多论文

基于墨西哥湾浮游有孔虫组合的MIS 9至MIS 5环流

墨西哥湾环流（LC）是北大西洋西部环流的一部分。记录其强度和减缓变化可以帮助我们描述更新世晚期的区域气候。为了重建GoM东部的海面和LC强度，我们研究了EN‐032‐18PC核心中浮游有孔虫的分布模式，涵盖海洋同位素阶段（MIS）9末期至MIS‐4早期。我们根据地表居民Globigerinoides ruber的稳定同位素（δ18O和δ13C）和两个动物组合重建了一系列古海洋事件。第一个组合解释了大部分冰川期和间冰期晚期，表明亚热带环境具有深层跃层，由于温暖的加勒比海水域的适度流入，LC降低。第二个组合解释了最热的间冰期，主要由热带物种、浅温跃层和夏季日照驱动的延长LC组成。总的来说，正如稳定同位素记录所支持的那样，在最温暖的间冰期，表层海洋条件导致了比冰川期更多的生态演替和不稳定。除了GoM与AMOC的关系外，作为向高纬度地区热传输的调节器，我们认为LC的波动取决于大气环流模式的迁移和天文日射强迫。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Paleoceanography and Paleoclimatology Earth and Planetary Sciences-Atmospheric Science

CiteScore

6.20

自引率

11.40%

发文量

107

期刊介绍： Paleoceanography and Paleoclimatology (PALO) publishes papers dealing with records of past environments, biota and climate. Understanding of the Earth system as it was in the past requires the employment of a wide range of approaches including marine and lacustrine sedimentology and speleothems; ice sheet formation and flow; stable isotope, trace element, and organic geochemistry; paleontology and molecular paleontology; evolutionary processes; mineralization in organisms; understanding tree-ring formation; seismic stratigraphy; physical, chemical, and biological oceanography; geochemical, climate and earth system modeling, and many others. The scope of this journal is regional to global, rather than local, and includes studies of any geologic age (Precambrian to Quaternary, including modern analogs). Within this framework, papers on the following topics are to be included: chronology, stratigraphy (where relevant to correlation of paleoceanographic events), paleoreconstructions, paleoceanographic modeling, paleocirculation (deep, intermediate, and shallow), paleoclimatology (e.g., paleowinds and cryosphere history), global sediment and geochemical cycles, anoxia, sea level changes and effects, relations between biotic evolution and paleoceanography, biotic crises, paleobiology (e.g., ecology of “microfossils” used in paleoceanography), techniques and approaches in paleoceanographic inferences, and modern paleoceanographic analogs, and quantitative and integrative analysis of coupled ocean-atmosphere-biosphere processes. Paleoceanographic and Paleoclimate studies enable us to use the past in order to gain information on possible future climatic and biotic developments: the past is the key to the future, just as much and maybe more than the present is the key to the past.