Relation between length-of-day variation and angular momentum of geophysical fluids

NCU Institutional Repository > 地球科學學院 > 地球科學學系 > 期刊論文 > Item 987654321/50546

請使用永久網址來引用或連結此文件: http://ir.lib.ncu.edu.tw/handle/987654321/50546

題名:	Relation between length-of-day variation and angular momentum of geophysical fluids
作者:	Chao,BF;Yan,HM
貢獻者:	地球科學系
關鍵詞:	WOBBLE;SCALES;EARTH;MODEL
日期:	2010
上傳時間:	2012-03-27 17:36:33 (UTC+8)
出版者:	國立中央大學
摘要:	The remarkable relation well observed between variation in the length of day (Delta LOD) and variation in the axial atmospheric angular momentum (Delta AAM) (plus the oceanic counterpart, to a much lesser extent) is a consequence of the conservation of angular momentum on planet Earth. Quantification of the exact Delta LOD-Delta AAM relation, which we seek in the present study, depends significantly on the extent to which the core participates, or is dynamically coupled with the mantle, in transmission of the axial Delta AAM from the mantle to the core. If, after conversion to the equivalent Delta LOD assuming core-mantle decoupling (as in current standard practice), the calculated axial Delta AAM (according to atmospheric general circulation models [GCMs]) is systematically greater than the observed Delta LOD, then we can conclude the presence, and, furthermore, estimate the strength, of the said dynamic core-mantle coupling. However, in this study we find the opposite instead, that the calculated Delta AAM (plus the small oceanic counterpart) is smaller than the observed Delta LOD by 10%-20% consistently across the intraseasonal and seasonal time scales. Our main logical conclusion is that the atmospheric GCMs in general underpredict the Delta AAM, by at least 10%-20% at the mentioned time scales, a fact of importance with respect to the assessment of GCMs. Therefore, the systematic discrepancy found between the Delta AAM-predicted and the observed Delta LOD masks the relevant information on core-mantle coupling that we seek.
關聯:	JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
顯示於類別:	[地球科學學系] 期刊論文

文件中的檔案:

檔案	描述	大小	格式	瀏覽次數
index.html		0Kb	HTML	675	檢視/開啟

在NCUIR中所有的資料項目都受到原著作權保護.

社群 sharing

資料載入中.....