Sea-surface dynamics diagnosed from satellite data and coupled models

根据卫星数据和耦合模型诊断海面动力学

• 批准号: 1536554
• 负责人: Thomas Haine
• 金额: $ 43.44万
• 依托单位: Johns Hopkins University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1536554&HistoricalAwards=false
• 关键词: Sea; surface; dynamics; diagnosed; satellite

A central question in oceanography and climate dynamics concerns the evolution of surface anomalies of a wide range of properties. Sea surface temperature anomalies regulate the exchange of heat between the upper ocean and the atmosphere, profoundly influencing ocean circulation, weather, the seasonal cycle, low-frequency climate variability, and climate change. In high latitudes, sea surface salinity anomalies have been associated with such variability, and with variability in ecosystems. It is unclear how to interpret the development and propagation of sea surface temperature anomalies, however, which are often analyzed in terms of spatiotemporally-lagged correlations. This ambiguity makes it difficult to constrain the underlying mechanisms, both in observations and in models. The main goal of this project is to diagnose, quantify, and understand the mechanisms controlling the propagation of ocean surface anomalies in temperature and salinity. This study will train one graduate student and its results will be disseminated broadly to scientists and the general public.This project applies a new framework developed by the investigators to understand how and why surface anomalies propagate and evolve. In particular, this new method to infers sea surface temperature transport fields greatly improves on earlier approaches by decomposing sea surface temperature evolution into advective, diffusive and relaxation components. Preliminary results applying this new method to historical North Atlantic sea surface temperature data and coupled climate model output motivate this study. The researchers intend to continue the sea surface temperature analysis to quantify anomaly dynamics using global observations, especially satellite imagery, as well as numerical models. The new framework also applies to other surface property fields, such as sea surface salinity. Three questions emerge from this work: Why do sea surface temperature anomalies apparently propagate at different speeds to the underlying currents? Why do sea surface temperature and sea surface salinity anomalies behave differently? and What determines the variations in the lateral diffusivity inferred from them? The researchers will use a hierarchy of models, including coupled climate models, to identify the mechanisms controlling anomaly evolution in these fields.

海洋学和气候动力学中的一个核心问题涉及广泛特性的表面异常的演变。海面温度异常调节上海与大气之间的热量交换，对海洋循环，天气，季节性周期，低频气候变化和气候变化产生深远影响。 在高纬度中，海面盐度异常与这种变异性和生态系统变异性有关。 然而，目前尚不清楚如何解释海面温度异常的发展和传播，但是通常会根据时空延伸的相关性进行分析。这种歧义使得在观测和模型中都很难限制基本机制。该项目的主要目标是诊断，量化和理解控制温度和盐分海面异常传播的机制。 这项研究将培训一名研究生，其结果将大致传播给科学家和公众。该项目采用了研究人员开发的新框架，以了解表面异常的传播和进化。尤其是，这种新方法渗透海面温度传输场通过将海面温度演变分解为对流，扩散和放松成分，从而大大改善了早期方法。初步的结果将这种新方法应用于历史悠久的北大西洋海面温度数据，并耦合气候模型输出激发了这项研究。 研究人员打算使用全球观测值，尤其是卫星图像以及数值模型来量化海面温度分析，以量化异常动力学。新框架还适用于其他表面特性场，例如海面盐度。这项工作来自三个问题：为什么海面温度异常显然以不同的速度传播到基础电流？ 为什么海面温度和海面盐度异常的行为不同？ 是什么决定了从它们推断出的横向扩散率的变化？ 研究人员将使用包括耦合气候模型在内的模型的层次结构来确定控制这些领域异常进化的机制。