A dynamically based method for estimating the Atlantic meridional overturning circulation at 26° N from satellite altimetry
A dynamically based method for estimating the Atlantic meridional overturning circulation at 26° N from satellite altimetry
复制标题
利用卫星测高估算北纬 26° 大西洋经向翻转环流的动态方法
DOI：
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
D. Smeed
中科院分区：
文献类型：
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作者：
A. Sanchez‐Franks;E. Frajka‐Williams;B. Moat;D. Smeed
摘要。大西洋经向翻转环流（AMOC）是一种大规模的洋流系统，它将1000米以上的温暖海水向北输送，并将较深的较冷的海水向南输送。AMOC的变化对气候系统有重大影响；因此，有必要长期监测AMOC的波动。目前最长的连续直接测量AMOC变化记录来自于2004年启动的RAPID-MOCHA-WBTS项目。RAPID计划和其他系泊计划彻底改变了我们对大规模循环的理解；然而，根据设计，它们被限制在单一纬度的测量，不能告诉我们2004年之前的任何事情。自1992年TOPEX/Poseidon卫星发射以来，几乎覆盖全球的卫星测高数据已经可用，并已被证明可以在年际时间尺度上提供可靠的地表海洋运输估计，包括以前调查海面高度变化与翻转环流之间经验相关性的研究。在这里，我们展示了一种基于动态方法的海洋环流直接计算方法，该方法利用卫星测高数据直接计算海洋中上部运输（UMO）、通过佛罗里达海峡的墨西哥湾流运输（GS）和AMOC，该方法结合了地学和26°N RAPID系泊的垂直流结构的时间平均值。基于卫星的传输分别捕获了26°N RAPID阵列在年际（18个月）时间尺度上56%、49%和69%的UMO、GS和AMOC传输变率。进一步研究水平输送的垂直结构表明，第一次斜压模态占内部地转变率的83%，正压和第一次斜压模态联合表示的动力高度占98%。最后，利用本文开发的方法重建了1993 ~ 2003年RAPID之前的UMO和AMOC。在26°N地区监测AMOC的卫星监测方法的有效实施，为监测所有纬度的大尺度环流奠定了起点。
Abstract. The large-scale system of ocean currents that transport warm waters in the upper 1000 m northward and return deeper cooler waters southward is known as the Atlantic meridional overturning circulation (AMOC). Variations in the AMOC have significant repercussions for the climate system; hence, there is a need for long-term monitoring of AMOC fluctuations. Currently the longest record of continuous directly measured AMOC changes is from the RAPID-MOCHA-WBTS programme, initiated in 2004. The RAPID programme and other mooring programmes have revolutionised our understanding of large-scale circulation; however, by design they are constrained to measurements at a single latitude and cannot tell us anything pre-2004. Nearly global coverage of surface ocean data from satellite altimetry has been available since the launch of the TOPEX/Poseidon satellite in 1992 and has been shown to provide reliable estimates of surface ocean transports on interannual timescales including previous studies that have investigated empirical correlations between sea surface height variability and the overturning circulation. Here we show a direct calculation of ocean circulation from satellite altimetry of the upper mid-ocean transport (UMO), the Gulf Stream transport through the Florida Straits (GS), and the AMOC using a dynamically based method that combines geostrophy with a time mean of the vertical structure of the flow from the 26∘ N RAPID moorings. The satellite-based transport captures 56 %, 49 %, and 69 % of the UMO, GS, and AMOC transport variability, respectively, from the 26∘ N RAPID array on interannual (18-month) timescales. Further investigation into the vertical structure of the horizontal transport shows that the first baroclinic mode accounts for 83 % of the interior geostrophic variability, and the combined barotropic and first baroclinic mode representation of dynamic height accounts for 98 % of the variability. Finally, the methods developed here are used to reconstruct the UMO and the AMOC for the time period pre-dating RAPID, 1993 to 2003. The effective implementation of satellite-based method for monitoring the AMOC at 26∘ N lays down the starting point for monitoring large-scale circulation at all latitudes.
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影响因子：
4.9
作者：
B. Moat;B. Sinha;S. Josey;J. Robson;P. Ortega;F. Sévellec;N. P. Holliday;G. McCarthy;A. New;J. Hirschi
通讯作者：
B. Moat;B. Sinha;S. Josey;J. Robson;P. Ortega;F. Sévellec;N. P. Holliday;G. McCarthy;A. New;J. Hirschi
影响因子：
5.2
作者：
D. Smeed;S. Josey;C. Beaulieu;W. Johns;B. Moat;E. Frajka‐Williams;D. Rayner;C. Meinen;M. Baringer-M
通讯作者：
D. Smeed;S. Josey;C. Beaulieu;W. Johns;B. Moat;E. Frajka‐Williams;D. Rayner;C. Meinen;M. Baringer-M
影响因子：
3.2
作者：
D. Smeed;G. McCarthy;S. Cunningham;E. Frajka‐Williams;D. Rayner;W. Johns;C. Meinen;M. Baringer;B. Moat;A. Duchez;H. Bryden
通讯作者：
D. Smeed;G. McCarthy;S. Cunningham;E. Frajka‐Williams;D. Rayner;W. Johns;C. Meinen;M. Baringer;B. Moat;A. Duchez;H. Bryden
影响因子：
3.2
作者：
B. Moat;D. Smeed;E. Frajka‐Williams;D. Desbruyères;C. Beaulieu;W. Johns;D. Rayner;A. Sanchez‐Franks;M. Baringer;D. Volkov;L. Jackson;H. Bryden
通讯作者：
B. Moat;D. Smeed;E. Frajka‐Williams;D. Desbruyères;C. Beaulieu;W. Johns;D. Rayner;A. Sanchez‐Franks;M. Baringer;D. Volkov;L. Jackson;H. Bryden
影响因子：
5.2
作者：
Bingham, Rory J.;Hughes, Chris W.;Williams, Richard G.
通讯作者：
Williams, Richard G.