Collaborative Research: Barrier Jets in the Gulf of Alaska - Causes, Impacts, and Interactions with Other Phenomena

合作研究：阿拉斯加湾的障壁急流 - 原因、影响以及与其他现象的相互作用

• 批准号: 0240269
• 负责人: George Young
• 金额: $ 24.31万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-05-01 至 2007-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0240269&HistoricalAwards=false
• 关键词: Collaborative; Research; Barrier; Jets; Gulf

The mesoscale atmospheric flow near coastlines with prominent terrain has a tremendous impact on those who live and work in the coastal environment. Yet this class of localized wind systems remains a challenging and important problem in weather prediction. One of the most common terrain-induced coastal flows, the barrier jet, creates especially dangerous weather conditions, particularly in southeast Alaska and the Pacific Northwest. The resulting severe winds pose a threat to life, property, and economic activities. Addressing these societal issues requires research to improve understanding of the dynamics of coastal barrier jets and the larger-scale weather conditions required for their formation. Recent advances in satellite remote sensing technology provide an opportunity to further understanding of barrier jets. For example, synthetic aperture radar (SAR) provides detailed measurements of the surface wind speed with resolutions of hundreds of meters over regions several hundred kilometers on a side. Moreover, with SAR the wind speed field can be observed to within 1 km of the coastline. These SAR speed observations can be combined with other observations and model output to provide high-resolution wind vector maps throughout the coastal zone. These SAR-derived wind maps from several thousand cases over the past 5 years, archived at the Johns Hopkins University Applied Physics Laboratory, represent a unique resource for the development of improved understanding of barrier jets along the Alaskan coast. This archive contains on the order of 100 cases of barrier jet flows over the Gulf of Alaska. In this project, the Principal Investigators will exploit this archive, along with additional imagery, in situ observations and numerical simulations to gain a greater understanding of the dynamics of barrier jets along the western coast of North America and of the larger-scale weather conditions required for their formation, thereby providing the basis for operational forecasting of this hazardous phenomenon.Additionally, the interactions between the flow associated with barrier jets and local ocean circulations will be investigated. The barrier jet climatology will be used to map the seasonal mean wind stress anomalies associated with barrier jets in the Gulf of Alaska. These wind stress anomaly maps will be used to determine the mean Ekman pumping associated with barrier jets and the resulting upper ocean response. These results well be checked against in situ observations from moored buoys and used to examine the impact of barrier jets on the marine ecosystem. These findings will provide important information to the fisheries industry as well as the marine biology and physical oceanography research communities.

地形突出的海岸线附近的中尺度大气流动对在沿海环境中生活和工作的人们产生巨大影响。 然而，这类局域风系统仍然是天气预报中具有挑战性的重要问题。 障碍急流是最常见的地形引起的沿海气流之一，它会造成特别危险的天气条件，特别是在阿拉斯加东南部和太平洋西北地区。 由此产生的强风对生命、财产和经济活动构成威胁。 解决这些社会问题需要进行研究，以增进对沿海屏障急流动力学及其形成所需的更大规模天气条件的了解。卫星遥感技术的最新进展为进一步了解障碍射流提供了机会。 例如，合成孔径雷达 (SAR) 可以对边长数百公里的区域提供数百米分辨率的表面风速详细测量。 此外，SAR可以观测到海岸线1公里范围内的风速场。 这些 SAR 速度观测结果可以与其他观测结果和模型输出相结合，提供整个沿海地区的高分辨率风矢量图。 这些来自过去 5 年数千个案例的 SAR 风图存档于约翰·霍普金斯大学应用物理实验室，代表了加深对阿拉斯加海岸屏障急流了解的独特资源。 该档案包含大约 100 个阿拉斯加湾上空屏障急流的案例。 在该项目中，主要研究人员将利用该档案以及其他图像、现场观测和数值模拟，以更好地了解北美西海岸屏障急流的动态及其形成所需的更大规模的天气条件，从而为这种危险现象的业务预报提供基础。此外，与屏障急流相关的流动与当地海洋环流之间的相互作用将被研究。 调查了。 屏障急流气候学将用于绘制与阿拉斯加湾屏障急流相关的季节性平均风应力异常。 这些风应力异常图将用于确定与障碍射流相关的平均埃克曼泵送以及由此产生的上层海洋响应。 这些结果可以与系泊浮标的现场观测进行核对，并用于检查屏障射流对海洋生态系统的影响。 这些发现将为渔业以及海洋生物学和物理海洋学研究界提供重要信息。