Observed and Modeled Aspects of Central-South American Low Level Jets

中南美洲低空急流的观测和模拟方面

• 批准号: 0106776
• 负责人: Jan Paegle
• 金额: $ 26.78万
• 依托单位: University of Utah
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-12-01 至 2005-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0106776&HistoricalAwards=false
• 关键词: Observed; Modeled; Aspects; Central; South

The low level jets (LLJs) that occur east of Andes Mountains in Central-South America and play a major role in the inter-basin transport of water vapor from the Amazon to the La Plata river basin are not well understood or predicted. This is, in part, due to poor observational coverage locally where spatial distribution of radiosonde sites is sparse and some of them have only one launch per day. This research project attempts to fill this observational gap and seek improved understanding and prediction of these LLJs. The research work is divided into three components. The first one is to study different features of the LLJs and their interactions with large-scale anomalies during the El Nino and La Nina summers using a global telescoping model that allows local high resolution. The second component is to launch radiosondes at two sites in Bolivia and one in Paraguay for three months in the Southern Hemisphere summer of 2002-2003 to obtain information on the diurnal and spatial structure of the LLJs. The third component will be to carry out short-term numerical simulations to calibrate and validate both the model and the reanalysis against the summer field observations. Understanding of these features may improve prediction with regional and global models. Collaborations between scientists in the U. S. and South American countries have great potential to elevate the research activities there and improve the long- term observational efforts locally. This last goal, if achieved, will have immeasurable benefits to the meteorological research and operational community.

低空急流（LLJ）出现在中南美洲安第斯山脉以东，在从亚马逊到拉普拉塔河流域的水蒸气跨流域输送中发挥着重要作用，但目前尚不清楚或预测不到。部分原因是当地观测覆盖范围较差，无线电探空仪站点的空间分布稀疏，其中一些站点每天仅发射一次。该研究项目试图填补这一观测空白，并寻求更好地理解和预测这些低空急流。研究工作分为三个部分。第一个是使用允许局部高分辨率的全球伸缩模型来研究低空急流的不同特征及其与厄尔尼诺和拉尼娜夏季期间大规模异常的相互作用。第二部分是在 2002-2003 年南半球夏季，在玻利维亚的两个地点和巴拉圭的一个地点发射无线电探空仪，为期三个月，以获得有关低空急流的昼夜结构和空间结构的信息。第三部分是进行短期数值模拟，以根据夏季实地观测来校准和验证模型和重新分析。了解这些特征可以改善区域和全球模型的预测。美国和南美国家科学家之间的合作具有巨大的潜力，可以提升那里的研究活动并改善当地的长期观测工作。最后一个目标如果实现，将为气象研究和业务界带来不可估量的好处。