An Analysis of SSH Ridges and SST Frontal Bands in Mid-Latitude Oceans

中纬度海洋海温脊和海温锋带分析

• 批准号: 1060397
• 负责人: Peter Cornillon
• 金额: $ 23.54万
• 依托单位: University of Rhode Island
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-04-15 至 2015-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1060397&HistoricalAwards=false
• 关键词: Analysis; SSH; Ridges; SST; Frontal

Intellectual Merit: Images of monthly averaged sea surface temperature (SST) front probability show zonal bands at mid-latitudes in all major ocean basins with a meridional separation of approximately 400 km. These bands are visually correlated with ridges of sea surface height (SSH) anomaly in the eastern South Pacific and with bathymetry. Furthermore, they are stable over many years. The dynamics giving rise to these features are not understood at present. Current hypotheses range from zonal jets resulting from baroclinic instability and geostrophic turbulence to preferred eddy pathways determined by mean flows or eddy interactions. The specific objectives of this project are: to quantify the relationship between persistent bands of frontal probability and persistent ridges in mean SSH fields; to determine the origin and maintenance of quasi-zonal bands of SST front probability; to characterize the inter-annual variability of the location of bands in the frontal probability fields; and, to analyze the impact of bottom topography on bands of frontal probability. The ubiquity of the observed zonal structures, their zonal extent, their persistence in time and the uniform meridional scale in all basins and all seasons suggests that they result from fundamental dynamic processes in the ocean. The tight correspondence between features in these structures and deep bathymetry suggests that they are involved with processes that extend well below the main thermocline. As such, understanding their origin will likely contribute to a better understanding of the general circulation of the ocean. Broader Impacts: In the course of the project, frontal data sets from a variety of satellite-derived SST fields extending from 1981 to present at a variety of spatial and temporal resolutions will be made available to the oceanographic community. Preliminary work suggests an ocean to atmosphere impact of the SST anomalies associated with frontal bands. Specifically, atmospheric water vapor is higher over these anomalies than the background. There is also a potential connection with geology in that the features associated with the bands are persistent in time - possibly over very long times with impacts on deposition on and scouring of the sea floor. Understanding the dynamics and persistence of the zonal striations will also be important to understanding ocean transports over long timescales affecting climate and thereby benefit our understanding of the ocean role in Earth's climate. This would also motivate efforts for parameterizing these ocean processes for representation in coarse coupled global climate models. The band detection algorithms and the analyses therein, as developed in this proposal, provide important scale information that can be useful in the design and maintenance of global ocean observing systems. This project will also support the training of one graduate student.

智力优势：月平均海面温度（SST）锋概率图像显示，在所有主要洋盆的中纬度地区，纬向间隔约为400公里的纬向带。 这些波段在视觉上与南太平洋东部海面高度（SSH）异常的脊和水深相关。 此外，它们多年来保持稳定。 目前还不了解产生这些特征的动力学。 目前的假设范围从纬向急流造成的斜压不稳定和地转湍流的首选涡路径确定的平均流量或涡的相互作用。 该项目的具体目标是：量化锋面概率的持续带与平均SSH场中的持续脊之间的关系;确定SST锋面概率的准纬向带的起源和维持;表征锋面概率场中带位置的年际变化;分析海底地形对锋面概率带的影响。 所观察到的纬向结构的普遍性、纬向范围、时间上的持续性以及所有盆地和所有季节的统一纬向尺度表明，它们是海洋基本动力过程的结果。 这些结构的特征与深海测深之间的紧密对应表明，它们涉及远低于主温跃层的过程。 因此，了解它们的起源可能有助于更好地了解海洋的一般环流。 更广泛的影响：在项目实施过程中，将向海洋学界提供从1981年到现在各种空间和时间分辨率的各种卫星SST场的锋面数据集。 初步工作表明，与锋带相关的SST异常的海洋到大气的影响。 具体来说，大气中的水蒸气是高于这些异常比背景。 与地质学也有潜在的联系，因为与环带有关的特征在时间上是持久的-可能持续很长时间，对海底的沉积和冲刷产生影响。 了解带状条纹的动态和持续性对于了解影响气候的长期海洋输送也很重要，从而有助于我们了解海洋在地球气候中的作用。 这也将促使人们努力将这些海洋过程参数化，以便在粗略的全球气候耦合模式中表现出来。 本提案中提出的波段探测算法及其分析提供了重要的尺度信息，可用于设计和维护全球海洋观测系统。 该项目还将支持培训一名研究生。