气候变化领域集成服务门户(CCPortal): The Variable and Changing Southern Ocean Silicate Front: Insights From the CESM Large Ensemble

CCPortal

DOI	10.1029/2017GB005816
	The Variable and Changing Southern Ocean Silicate Front: Insights From the CESM Large Ensemble
	Freeman N.M.; Lovenduski N.S.; Munro D.R.; Krumhardt K.M.; Lindsay K.; Long M.C.; Maclennan M.
发表日期	2018
ISSN	0886-6236
EISSN	1944-9224
起始页码	752
结束页码	768
卷号	32 期号:5
英文摘要	The location of the Southern Ocean Silicate Front (SF) is a key indicator of physical circulation, biological productivity, and biogeography, but its variability in space and time is currently not well understood due to a lack of time-varying nutrient observations. This study provides a first estimate of the spatiotemporal variability of the SF, defined using the silicate-to-nitrate (Si:N) ratio as simulated by the Community Earth System Model (CESM) Large Ensemble (1920–2100), and its response to a changing Southern Ocean. The latitude where Si:N = 1 largely coincides with regions of high gradients in silicate and the observed position of the Antarctic Polar Front (PF) and serves as an indicator of waters with adequate nutrients available for diatom growth. On seasonal to interdecadal time scales, vasriability in the location of the SF is largely determined by biological nutrient utilization and Southern Ocean bathymetry, respectively. From 1920 to 2100, under historical and RCP8.5 forcing, the zonally averaged SF shifts poleward by ∼3° latitude, with no discernible shift in the position of the simulated location of the PF or the core of the Antarctic Circumpolar Current. A more poleward SF is primarily driven by long-term reductions in silicate and nitrate concentrations at the surface as a consequence of greater iron availability and a warmer, more stratified Southern Ocean. These results suggest a decoupling of the SF and PF by the end of the century, with implications for local biogeography, global thermocline nutrient cycling, and the interpretation of paleoclimate records from deep sea sediments. ©2018. American Geophysical Union. All Rights Reserved.
英文关键词	Antarctic Circumpolar Current; Antarctic Polar Front; climate variability; Silicate Front; Southern Ocean
语种	英语
scopus关键词	climate modeling; climate variation; concentration (composition); decadal variation; nitrate; nutrient cycling; nutrient dynamics; paleoclimate; polar front; silicate; spatiotemporal analysis; stratification; thermocline; Antarctic Circumpolar Current; Southern Ocean; Bacillariophyta
来源期刊	Global Biogeochemical Cycles
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/129831
作者单位	Department of Atmospheric and Oceanic Sciences and Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, CO, United States; Now at Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, United States; Environmental Studies Program and Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, CO, United States; Climate and Global Dynamics Laboratory, National Center for Atmospheric Research, Boulder, CO, United States
推荐引用方式 GB/T 7714	Freeman N.M.,Lovenduski N.S.,Munro D.R.,et al. The Variable and Changing Southern Ocean Silicate Front: Insights From the CESM Large Ensemble[J],2018,32(5).
APA	Freeman N.M..,Lovenduski N.S..,Munro D.R..,Krumhardt K.M..,Lindsay K..,...&Maclennan M..(2018).The Variable and Changing Southern Ocean Silicate Front: Insights From the CESM Large Ensemble.Global Biogeochemical Cycles,32(5).
MLA	Freeman N.M.,et al."The Variable and Changing Southern Ocean Silicate Front: Insights From the CESM Large Ensemble".Global Biogeochemical Cycles 32.5(2018).