Dynamics and Moist Thermodynamics of the Boreal Summer Intraseasonal Oscillation

北方夏季季节内振荡的动力学和湿润热力学

• 批准号: 0647995
• 负责人: Bin Wang
• 金额: $ 52.68万
• 依托单位: University of Hawaii
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-03-01 至 2010-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0647995&HistoricalAwards=false
• 关键词: Dynamics; Moist; Thermodynamics; Boreal; Summer

Intraseasonal oscillations in the tropics drive week-to-week and month-to-month variations in precipitation and in the risk of tropical cyclones. Thus they are important for the most significant weather and climate variations in these regions. Intraseasonal oscillations in the boreal summer are potentially more complex than the more familiar wintertime Madden-Julian oscillation, because they are not confined to the equatorial band, they exhibit complex interactions with the ocean and with the seasonal mean climate, and they involve a wide range of modes and scales. Current coupled climate models do not simulate the summertime intraseasonal oscillations well.The PIs will analyze observations in order to define the detailed structures of the boreal summer intraseasonal oscillations, including their seasonal variations, the coupling between timescales, and their interactions with seasonal variability. These studies will employ newly available remotely sensed data from satellites, ground-based data, and a very long historical record of precipitation. Modeling studies, using a hierarchy of coupled atmosphere-ocean models, as well as mechanistic intermediate models, will be carried out to identify the mechanisms that drive the BSISO and determine its timescales, to investigate the predictability of the BSISO and its interactions with the ocean, and to explore how it is influenced by seasonal anomalies, such as El Nino.Broader impacts of this work are in the importance of the BSISO for intraseasonal forecasting in the tropics, with implications for predicting floods and droughts, and in training a postdoctoral associate and a graduate student.

热带地区的季节内波动导致降水量和热带气旋风险出现每周和每月的变化。因此，它们对于这些地区最显着的天气和气候变化非常重要。北半球夏季的季节内振荡可能比更熟悉的冬季马登-朱利安振荡更为复杂，因为它们并不局限于赤道带，它们表现出与海洋和季节性平均气候的复杂相互作用，并且涉及广泛的范围。模式和音阶。目前的耦合气候模型不能很好地模拟夏季季节内振荡。PI 将分析观测结果，以确定北方夏季季节内振荡的详细结构，包括它们的季节变化、时间尺度之间的耦合以及它们与季节变化的相互作用。这些研究将利用新近获得的卫星遥感数据、地面数据和长期的降水历史记录。将使用大气-海洋耦合模型层次结构以及机械中间模型进行建模研究，以确定驱动 BSISO 的机制并确定其时间尺度，研究 BSISO 的可预测性及其与海洋的相互作用，并探讨它如何受到季节性异常（例如厄尔尼诺现象）的影响。这项工作的更广泛影响在于 BSISO 对于热带地区季节内预报的重要性，对预测洪水具有影响和干旱，以及培训博士后助理和研究生。