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Period-depth diagram of layer-integrated spectrum of sea temperature variability for the interannual band derived from Argo data of 2004-13. The color scale depicts the globally averaged harmonic amplitude for each depth layer.
Source publication
Using the newly available decade-long Argo data for the period 2004-13, a detailed study is carried out on deriving four-dimensional (4D) modality of sea temperature in the upper ocean with emphasis on its interannual variability in terms of amplitude, phase, and periodicity. Three principal modes with central periodicities at 19.2, 33.8, and 50.3...
Contexts in source publication
Context 1
... a measure of the strength of oceanic variability, an ''integrated spectrum'' of sea temperature time series is derived for the interannual band ( Fig. 1): that is, the harmonic amplitude with respect to depth and ...
Context 2
... N(z k ) is the total number of valid grid points at depth z k . In the upper layers between 1 and 22 (corresponding to 0-220 m), a striking subsurface belt of maximum interannual variability is well defined. Three prominent ENSO-related modes centered around 90-100 m (as labeled with A, B, and C in Fig. 1) can be clearly identified. It is also obvious that the general trend of sea temperature variability exhibits an upward decrease with moderate surface manifestation, and a downward decrease with very little interannual change below layer 37 (corresponding to 500 ...
Context 3
... least two salient characteristics can be further derived for modes A-C: namely, peaking depth and period drift (as shown in Figs. 3a,b, respectively). As far as mode A (B or C) is concerned, the interannual variability is found to reach its maximum at the depth of 100 m (90 m) ( Fig. 3a) and becomes very weak at about 200 m (see also Fig. 1: note that the peak corresponding to mode C becomes insignificant and cannot be effectively resolved below 220 m). Moreover, within the range of significant interannual variability, a period drift is evident for modes B and C: the former increases from 31 months at sea surface to 35 months at 90 m and remains unchanged until 300 m, ...
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... further understand the formation mechanism of the Niño pipe, we refocus on equatorial Rossby/Kelvin wave dynamics in relation with the EUC. At least three issues need to be clarified: 1) Why do the subsurface maxima of combined interannual sea temperature amplitude as represented by the Niño pipe coincide with the pathway of EUC in space (Fig. 8)? 2) Why is the core of the Niño pipe shifted slightly but significantly from the equator (Fig. 9)? 3) Why does the Niño pipe as well as the tropical Pacific zone have a three-peak structure in their interannual sea temperature modality (Figs. 1 and 3)? To examine the first issue, it is necessary to understand that Rossby waves play a critical role in the transient adjustment of ocean circulation to changes in large-scale atmospheric forcing ( Chelton and Schlax 1996). ...
Context 5
... local and remote atmospheric circulation anomalies. The high correlation between OLR and upper-ocean sea temperature in their spectra suggests a direct oceanic thermal response to the atmospheric solar forcing. Specifically, the bandpassed time series of normalized amplitudes of OLR and sea temperature at 100-m depth for modes A-C are shown in Fig. 10. The well-defined phase reversal for all three modes suggests that atmospheric forcing is likely to be significant for each of the identified harmonic. Furthermore, as estimated by Chelton and Schlax (1996), a sea level variation of 5 cm may correspond to a thermocline displacement of about 50 m. Figure 2b thus also confirms that the ...
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Citations
... ( 表 1) [18~27] ,供广大用户免费下载共享,极大地方 便了人们的应用 [28~37] 。 C-ARDC 利用一种简单有 效且易于操作的逐步订正法 [23,38] ,并结合一个混合 层模型 [39] ( 用来反推对应剖面上的表层温度和盐 度,以弥补早期布放的 Argo 浮标无法观测离海面约 10 m 以浅深度内温度、盐度资料的不足) ,仅利用 混合 层 年 际 变 化 [29] 、 太 平 洋 流 场 [30] 、 台 湾 以东海域海温与温跃层 特征 [ 热带 印 度 洋 声 场 [32] 、 全球海洋最大混合层深 度 估 算 [33] 、 上 层 海 洋 季节和年际四维变化结 构 [34,35] [62,63] 。 吴晓芬等 [64] 分析了热 Fig. 7 Averaged longitude-depth cross section of recovered harmonic amplitude of sea temperature variability along 1°S of the Pacific sector (120~285°E) [34] 2 5 4 地球科学进展 第 31 卷 早在 2004 年,Argo 资料就被应用于改进海洋 资料同 化 和 模 式 中 的 物 理 过 程 [81] , 同 时 也 用 来 提高 ENSO 和我国夏季降水 的 气 候 预 测 水 平 [82,83] ( 图 8) ;Argo 在国家气候中心全球海洋资料四维同 化系统( NCC-GODAS) 中为短期气候预测系统提供 了重要海洋异常状况的初始信号 [84] ,为全球气候预 测业务模式系统及 ENSO 预报能力的提高发挥了重 要作用。 目前该同化系统已经发展到第二代 [85,86] , 其对热带太平洋海面高度的年际和 10 年际变化及 2 种类型的厄尔尼诺信号的捕捉能力明显优于第 一代。 中国科学院大气物理研究所朱江 [87] 带领的团 图 8 Zebiak-Cane 海洋模式计算得到的热带西太平洋次表层温度距平与混合层深度的关系及与实况的对比 [84] Fig. 8 Comparison of observed relationship between subsurface temperature anomaly and mixed-layer depth in the tropical western Pacific with that calculated by the parameterization scheme in Zebiak-Cane oceanic model [84] 黄色代表利用 Argo 资料改进后方案的计算结果 CORA) [88] ,目前已经扩展到全球海洋 [89] ,明显提高 [94] ,并应用到海洋内部 流场验证的系统研究 [95,96] ;利用 Argo 资料改进对海 洋复杂空间变化( 尺度小于气候尺度) 的研究 [97] ,以 ...
... ( 表 1) [18~27] ,供广大用户免费下载共享,极大地方 便了人们的应用 [28~37] 。 C-ARDC 利用一种简单有 效且易于操作的逐步订正法 [23,38] ,并结合一个混合 层模型 [39] ( 用来反推对应剖面上的表层温度和盐 度,以弥补早期布放的 Argo 浮标无法观测离海面约 10 m 以浅深度内温度、盐度资料的不足) ,仅利用 混合 层 年 际 变 化 [29] 、 太 平 洋 流 场 [30] 、 台 湾 以东海域海温与温跃层 特征 [ 热带 印 度 洋 声 场 [32] 、 全球海洋最大混合层深 度 估 算 [33] 、 上 层 海 洋 季节和年际四维变化结 构 [34,35] [62,63] 。 吴晓芬等 [64] 分析了热 Fig. 7 Averaged longitude-depth cross section of recovered harmonic amplitude of sea temperature variability along 1°S of the Pacific sector (120~285°E) [34] 2 5 4 地球科学进展 第 31 卷 早在 2004 年,Argo 资料就被应用于改进海洋 资料同 化 和 模 式 中 的 物 理 过 程 [81] , 同 时 也 用 来 提高 ENSO 和我国夏季降水 的 气 候 预 测 水 平 [82,83] ( 图 8) ;Argo 在国家气候中心全球海洋资料四维同 化系统( NCC-GODAS) 中为短期气候预测系统提供 了重要海洋异常状况的初始信号 [84] ,为全球气候预 测业务模式系统及 ENSO 预报能力的提高发挥了重 要作用。 目前该同化系统已经发展到第二代 [85,86] , 其对热带太平洋海面高度的年际和 10 年际变化及 2 种类型的厄尔尼诺信号的捕捉能力明显优于第 一代。 中国科学院大气物理研究所朱江 [87] 带领的团 图 8 Zebiak-Cane 海洋模式计算得到的热带西太平洋次表层温度距平与混合层深度的关系及与实况的对比 [84] Fig. 8 Comparison of observed relationship between subsurface temperature anomaly and mixed-layer depth in the tropical western Pacific with that calculated by the parameterization scheme in Zebiak-Cane oceanic model [84] 黄色代表利用 Argo 资料改进后方案的计算结果 CORA) [88] ,目前已经扩展到全球海洋 [89] ,明显提高 [94] ,并应用到海洋内部 流场验证的系统研究 [95,96] ;利用 Argo 资料改进对海 洋复杂空间变化( 尺度小于气候尺度) 的研究 [97] ,以 ...
... Global distribution of the meridional transport of fluid trapped by mesoscale eddies[65] ( a) 流经纬向断面的涡致经向输送;( b) 涡致经向输送的纬向积分 ( a) Eddy-induced meridional transport through a zonal cross-section per degree of longitude; ( b) Distribution of the total zonal-integrated meridional transport induced by eddies as a function of latitude 图 7 太平洋海域沿 1°S 断面海温变化谐振幅[34] ...
This paper reviews the current achievements of the China Argo project. It considers aspects of both the construction of the Argo observing array, float technology, and the quality control and sharing of its data. The developments of associated data products and data applications for use in the fields of ocean, atmosphere, and climate research are discussed, particularly those related to tropical cyclones (typhoons), ocean circulation, mesoscale eddies, turbulence, oceanic heat/salt storage and transportation, water masses, and operational oceanic/atmospheric/climatic forecasts and predictions. Finally, the challenges and opportunities involved in the long-term maintenance and sustained development of the China Argo ocean observation network are outlined. Discussion also focuses on the necessity for increasing the number of floats in the Indian Ocean and for expanding the regional Argo observation network in the South China Sea, together with the importance of promoting the use of Argo data by the maritime countries of Southeast Asia and India.
A decade of newly available Argo float data for the period 2004-13 are used to investigate the three-dimensional structures of upper-ocean seasonality with emphasis on the vertical aspects of annual and semiannual cycles, yielding three main findings with oceanographic implications. First, the vertical evolution of the horizontal pattern of annual and semiannual amplitudes appears to be highly nonlinear, suggesting that the thermodynamic causes are depth dependent. The global ocean seasonality exhibits a vertically varying pattern in space, including midlatitude maxima in the near-surface layer due to solar forcing, zonal strips in the subsurface layer due to the equatorial current system, and systematic westward phase propagation in the intermediate layer due to annual Rossby waves. Second, a zone of 500 +/- 300-m depths along with a 6-month periodicity are chosen as appropriate space-time windows for detecting eddy signatures via Argo-derived temperature amplitude and phase, respectively. It is revealed that the eddy-induced blobby pattern observed previously by satellite altimeter appears in the Agro result as woodsy bulks, which can be well illustrated in the semiannual amplitude and phase maps at window depths. Meanwhile, six eddy deserts paired in each ocean basin have also been identified. Third, the existence of a dozen vertical quasi-annual amphidromes is first reported, with cophase lines that may radiate toward the similar to 2000-m lower limit of Argo measurement. The well-known global meridional overturning circulation and the pseudozonal overturning currents in the equatorial Pacific, Atlantic, and Indian Oceans may possibly contribute to the observed vertical amphidromes.
