| 项目编号: | 1360237
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| 项目名称: | Studies of Madden-Julian Oscillation (MJO) Initiation Using Atmospheric Sounding Data |
| 作者: | Richard Johnson
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| 承担单位: | Colorado State University
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| 批准年: | 2013
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| 开始日期: | 2014-04-01
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| 结束日期: | 2018-03-31
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| 资助金额: | USD755986
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| 资助来源: | US-NSF
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| 项目类别: | Standard Grant
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| 国家: | US
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| 语种: | 英语
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| 特色学科分类: | Geosciences - Atmospheric and Geospace Sciences
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| 英文关键词: | datum
; mjo
; mjo event
; madden-julian oscillation
; complete mjo cycle
; project
; other priority sounding sites
; mjo lifecycle
; mjo initiation
; radiosonde datum
; datum product
; radar datum
; mjo prediction
; field datum
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| 英文摘要: | This project consists of processing, analysis, and exploration of field data taken during the Dynamics of the Madden-Julian Oscillation (DYNAMO) field campaign, which took place in the Indian Ocean during the 2011-2012 Fall and Winter seasons. The Madden-Julian Oscillation (MJO) is an envelope of organized convection that propagates from the Indian Ocean to the Pacific Ocean and constitutes the dominant form of intraseasonal precipitation and atmospheric circulation variability in the tropics. The MJO influences a variety of tropical weather and climate phenomena,including tropical cyclones (affecting hurricanes in the Gulf of Mexico), the onset and intraseasonal fluctuations of the monsoons and rainfall over Asia, Australia, Africa, and the Americas, and the onset of El Nino events. Two complete MJO cycles were observed during DYNAMO.
Data for this project come from a 6-station network of radiosonde (weather balloon) stations which were organized and co-managed by the PI during DYNAMO, augmented by a number of other Priority Sounding Sites throughout the Indian and Western Pacific Oceans. The overall goal of the proposal is to use the sounding data, after some additional processing and in concert with other DYNAMO observations, to examine the processes associated with the evolution of atmospheric moisture during the MJO lifecycle. Preliminary results show that there was a gradual increase in lower to middle tropospheric relative humidity leading up to the initiation of both MJO events, and this project seeks to identify the mechanisms leading to the build-up. One avenue to address this question is the development of moisture budgets from the sounding data, another is the use of radar data from the campaign to assess the contribution of clouds of various types to atmospheric moistening. Additional work will consider the role of the diurnal cycles of sea surface temperature and non-precipitating clouds, and variations in the depth of the atmospheric mixed layer (the layer of the atmosphere in contact with, and strongly influenced by, the underlying sea surface).
Despite its importance and concerted efforts over several decades, the MJO has not yet been adequately explained, and global atmospheric circulation models have difficulty simulating and predicting it. The research thus has societal broader impacts as it is expected to contribute to improved understanding and prediction of MJO events. More specifically, the PI will work with modeling centers around the world to enhance MJO prediction, most importantly by providing data products for their use such as large-scale forcing fields for use in numerical simulations of MJO initiation. The PI notes that all radiosonde data collected through his DYNAMO sub-project will be hosted on several websites, and work funded here would enhance that data through quality control, removal of island effects, resolution of inhomogeneities, etc. In addition, the project provides funding for a graduate student, thereby providing for the future workforce in this research area. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/97212
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| Appears in Collections: | 影响、适应和脆弱性
气候减缓与适应
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| Recommended Citation: | |
Richard Johnson. Studies of Madden-Julian Oscillation (MJO) Initiation Using Atmospheric Sounding Data. 2013-01-01.
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