Study on equatorial cumulous convection and atmospheric waves using radiosonde observations and data assimilation modeling

利用无线电探空仪观测和数据同化模型研究赤道积对流和大气波

基本信息

批准号：
12440127
负责人：
NAKAMUR Atakuji
金额：
$ 9.73万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12440127/
关键词：
Atmospheric waves Mesoscale modeling Water vapor Mesopause Cumulous convection Equatorial region Airglow imaging Transport between the troposphere and the stratosphere オゾン重力波欣起対流圏成層圏成層圏物質交換重力波励起

项目摘要

In the equatorial region, cumulous convections are extremely active which generate atmospheric waves. These waves propagate upward, affecting the circulations in the lower and middle atmospheres, as well as transporting energy into the thermosphere. In this study, we clarified the mechanisms underlying the convection and the atmospheric waves by comparing the details of the observational results and the four dimensional dataset produced by the numerical modeling by means of data assimilation technique. We, first, analyzed the observational dataset accumulated so far, and then new dataset collected by a novel precise observation techniques is utilized. Precise water vapor measurement around the tropopause was carried out in Indonesia, and the transport associated with the convective activity has been clarified. Airglow imaging observation over one year in Indonesia has revealed the climatology of small scale gravity waves in the mesopause region for the first time, and clear association with horizontal distributions of cumulous clouds has been found. A long term observation by the MLT radars clarified the relation between the intraseasonal variations in the MLT region and atmospheric wave activity in the lower atmosphere. Three dimensional modeling using these observational data clearly showed the gravity waves excited by the cumulous convection propagate into the mesospause region and break there. Further comparisons with the airglow imaging observations clarified the mechanism of gravity wave generation, propagation, breaking and associated atmospheric instability. Input from the new satellite data and further improvement of modeling such as extension of the simulation space and improvement of resolutions would greatly contribute to the understanding of global impact of the atmospheric waves in the lower and middle atmosphere.

在赤道区域中，杂乱的对流非常活跃，产生大气波。这些波向上传播，影响下层和中间大气中的循环，并将能量运输到热层中。在这项研究中，我们通过比较观测结果的细节以及通过数据同化技术的数值建模产生的四个维数据集来阐明对流和大气波的基础机制。首先，我们分析了到目前为止积累的观察数据集，然后利用了新型精确观察技术收集的新数据集。在印度尼西亚进行了对流层面周围的精确水蒸气测量，并阐明了与对流活动相关的运输。在印度尼西亚一年多的气流成像观察发现，首次发现了间层区域中小规模重力波的气候，并且发现了与累积的云层水平分布的明确关联。 MLT雷达的长期观察阐明了MLT区域的季节内变化与下大气中的大气波活性之间的关系。使用这些观察数据的三维建模清楚地表明，由于对流群的对流激发的重力波传播到中间区域并闯入那里。进一步比较气流成像观测结果阐明了重力波产生，传播，破裂和相关大气不稳定性的机理。来自新的卫星数据的输入以及建模的进一步改进，例如扩展模拟空间和分辨率的改进将极大地有助于理解较低和中间大气中大气波的全球影响。