Mechanism of the Madden-Julian Oscillation (MJO) Viewed from Scale Interactions in the Frequency Domain

该项目将通过对大气和大气-海洋耦合系统的诊断分析和数值模拟，研究热带地区马登-朱利安振荡(MJO)的演变。MJO是季节内变率的重要组成部分，对热带和热带外太平洋/北美地区的环流和降水变率起着重要的调节作用。MJO还影响亚澳夏季风。由于被夹在两个显著的波动时间尺度之间--较短的时间尺度天气和较长时间尺度的季节至年际变化--MJO直到最近才得到所需的研究关注。Krishnamurti博士(FSU)将研究频率内相互作用在MJO发生和进化中的作用。将整合大气和大气-海洋系统的高分辨率数值模式，以了解在MJO可变性的背景下，边界层水分、感热和动量通量的时空结构。该项目是由PI的假设驱动的，即MJO时间尺度的气流成分通过与一对天气时间尺度(2至6天)环流特征的频率相互作用而放大，特别是在行星边界层。全球20多亿人感受到了亚洲季风预报的社会经济影响。季节内海浪的通过似乎对季风的干湿周期有很大影响。这项工作有可能导致MJO的实时预报模式，从而为季风持续的干湿时段提供重要的指导。

The project will investigate the evolution of the Madden-Julian Oscillation (MJO) in the tropics from diagnostic analysis of observations and numerical modeling of the atmosphere and the coupled atmosphere-ocean system. MJO is a key component of intra-seasonal variability, and plays a significant role in modulating the circulation and precipitation variability in the tropics and the extratropical Pacific/North American region. MJO also influences the Asian-Australian summer monsoons. Because of being sandwiched between two notable fluctuation time-scales--the shorter time-scale weather and the longer time-scale seasonal-to-interannual variability--MJO has not received the needed research attention up until recently. Dr. Krishnamurti (FSU) will investigate the role of intra-frequency interactions in MJO genesis and evolution. High-resolution numerical models of the atmosphere and the atmosphere-ocean system will be integrated to understand the spatio-temporal structure of the boundary layer fluxes of moisture, sensible heat, and momentum, in context of MJO variability. The project is driven by the PI's hypothesis that MJO time-scale flow components amplify from frequency interactions with a pair of synoptic time-scale (2-to-6 days) circulation features, particularly in the planetary boundary layer. The socio-economic impacts of Asian monsoon forecasts are felt by more than two billion people on the earth. The passage of intra-seasonal waves seems to have substantial impact on the wet and dry spells of the monsoon. This work has the potential to lead to real time prediction models of the MJO that can provide important guidance for sustained wet and dry spells of the monsoon.