Impact of Recent Westerly Wind Trends on the Southern Ocean.

南大洋洋流对海洋中的生物和化学、南极海冰的形成以及热量和碳从大气向海洋的转移产生了重大影响，从而调节了地球的气候。吹过南半球的强大的近地表大气层风在导致南半球和邻近海洋内部流动的过程中发挥了关键作用。观测显示，在过去40年里，这些风发生了重大变化，包括自2000年以来一直暂停的20世纪末峰值风的加强和向南极移动。鉴于风和洋流之间已知的联系，有理由预计，观测到的风趋势将导致或已经导致南大洋趋势的变化。然而，这一点还没有得到详细的研究。该项目将通过量化最近的风场停顿和南大洋风向区域变化的影响来解决知识差距问题。该项目将为AGU Bridge项目的一名研究生和几名本科生提供培训，将研究结果纳入教学计划，通过非正式的外展活动和夏令营与巴尔的摩市当地学校接触，并通过建立现有的NSF GEOPath项目来扩大对地球科学的参与。这项研究将利用海洋和气候模型模拟与观测相结合的方法，提高我们对南大洋对南半球风应力时间和区域变化的响应的理解。将对风和浮力强迫突变的理想化模拟进行分析，以量化南大洋对西风变化的反应的规模和时间尺度。然后，研究人员将使用观测到的大气变化和海洋观测带来的模拟，量化南大洋最近发生的变化中有多少可以用风的趋势来解释。通过将新的诊断方法应用于下一代海洋和气候模型来解决关键的知识差距，将提高我们对南大洋最近变化的原因及其对南极和全球气候的影响的理解。它还将提供对未来变化的洞察，无论是近期还是长期，当臭氧空洞缓慢恢复时，预计纬向风的微弱趋势，以及本世纪晚些时候，当风的变化可能取决于平流层臭氧恢复和温室气体持续增加之间的平衡时。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The currents of the Southern Ocean have a major impact on the biology and chemistry in the oceans, the formation of Antarctic sea-ice, and the transfer of heat and carbon from the atmosphere into the oceans, regulating Earth’s climate. The strong near-surface atmospheric winds that blow across the southern hemisphere play a key role in causing the flow within the Southern and neighboring oceans. Observations have shown substantial changes in these winds over the last four decades, including a strengthening and movement towards the south pole of the peak winds at the end of the twentieth century, that has paused since 2000. Given the known linkages between winds and ocean flow it is reasonable to anticipate that the observed wind trends will lead, or have already led, to changes in Southern Ocean trends. However, this has not yet been examined in detail. This project will address the knowledge gap by quantifying the impact the recent wind pauses and regional variations in wind trends on the Southern Ocean. This project will provide training for an AGU Bridge program graduate student and for several undergraduate students, incorporate findings into lesson plans, engage with local Baltimore City schools through informal outreach activities and summer camps, and broaden participation in the geosciences by building on existing NSF GEOPaths projects.This research will improve our understanding of the response of the Southern Ocean to temporal and regional variations in southern hemisphere wind stresses using a combination of ocean and climate model simulations together with observations. Idealized simulations with abrupt changes in the wind and buoyancy forcing will be analyzed to quantify the magnitude and time scales of the response of the Southern Ocean to changes in westerly winds. Researchers will then use simulations forced by observed atmospheric changes and ocean observations to quantify how much of the recent changes in the Southern Ocean can be explained by trends in the winds. Addressing key knowledge gaps with new diagnostics applied to next-generation ocean and climate models will improve our understanding of the causes of recent changes in the Southern Ocean and their impact on Antarctic and global climate. It will also provide insights into future changes, both near and long-term, when weak trends in the zonal winds are expected as the ozone hole slowly recovers, and later in the century when wind changes will likely depend on the balance between stratospheric ozone recovery and continued increases in greenhouse gases.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.