Modification of Saharan air layer and environmental shear over the eastern Atlantic Ocean by dust-radiation effects

NCU Institutional Repository > 地球科學學院 > 大氣物理研究所 > 期刊論文 > Item 987654321/50328

jsp.display-item.identifier=請使用永久網址來引用或連結此文件: http://ir.lib.ncu.edu.tw/handle/987654321/50328

题名:	Modification of Saharan air layer and environmental shear over the eastern Atlantic Ocean by dust-radiation effects
作者:	Chen,SH;Wang,SH;Waylonis,M
贡献者:	大氣物理研究所
关键词:	TROPICAL CYCLOGENESIS;NUMERICAL SIMULATIONS;OPTICAL-PROPERTIES;MINERAL DUST;AEROSOL;MODEL;INTENSITY;DISTURBANCES;VALIDATION;HURRICANES
日期:	2010
上传时间:	2012-03-27 17:29:30 (UTC+8)
出版者:	國立中央大學
摘要:	[1] This study investigates the influence of dust-radiation effects on the modification of the Saharan air layer (SAL) and environmental shear. A tracer model based on the Weather Research and Forecast model was developed to examine the influence using a dust outbreak event. Two numerical experiments were conducted with (ON) and without (OFF) the dust-radiation effects. Both simulations reasonably reproduced SAL's features. However, the 700 hPa maximum temperature within SAL was slightly underestimated and shifted northwestward from OFF. These were improved from ON, but the maximum temperature became slightly overestimated, which might be due to inaccurate optical properties. The dust-radiation interactions mainly warmed the dusty air between 750 and 550 hPa because dust shortwave absorption dominated dust longwave cooling. Another major warming area was found near the surface over the ocean due to longwave radiative heating by dust aloft. The modification of temperature resulted in an adjustment of the vertical wind shear. To the south of SAL, where easterly wave disturbances and tropical storms usually occur, the vertical zonal wind shear increased by about 1 similar to 2.5 m s(-1) km(-1) from 750 to 550 hPa, resulting in a maximum wind change of 3 similar to 5 m s(-1), a 30 similar to 40% increase, around the top of this layer. The enhancement of the vertical shear in this layer could potentially have an impact on TC genesis and development. The dust-radiation effects also modified the moisture and dust distribution, which can have a feedback (i.e., a secondary effect) on the heating profile and the vertical shear.
關聯:	JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
显示于类别:	[大氣物理研究所 ] 期刊論文

文件中的档案:

档案	描述	大小	格式	浏览次数
index.html		0Kb	HTML	495	检视/开启

在NCUIR中所有的数据项都受到原著作权保护.

社群 sharing

数据加载中.....