Analysis of MJO Wind-Flux Feedbacks in the Indian Ocean Using RAMA Buoy Observations
-
- RILEY DELLARIPA Emily M.
- Department of Atmospheric Science, Colorado State University, Colorado, USA
-
- MALONEY Eric D.
- Department of Atmospheric Science, Colorado State University, Colorado, USA
この論文をさがす
抄録
Observations spanning 2004-2012 from two Research Moored Array for African-Asian-Australian Monsoon Analysis and Prediction (RAMA) buoys along the equator in the Indian Ocean are used in conjunction with Tropical Rainfall Measuring Mission (TRMM) to assess the relative importance of surface latent heat fluxes to intraseasonal convection. This work is motivated by previous observational and modeling studies that have suggested the importance of wind-induced surface fluxes to the dynamics of the Madden-Julian Oscillation (MJO).<br> Intraseasonal variability is isolated in two ways: 1) 20-100-day bandpass filtering and 2) using the global real time multivariate MJO index. Linear regression shows latent heat flux anomalies to be between 4 % and 8 % of precipitation anomalies when the two variables are compared using similar Wm-2 energy units. From a moist static energy budget viewpoint, these results confirm the potential of wind-induced latent heat fluxes to aid destabilization of MJO convection. Results derived from using both simple intraseasonal filtering and global MJO indices indicate that precipitation leads latent heat flux on the order of a few days, indicating surface fluxes may be more important for maintenance of deep MJO convection in addition to helping set the MJO’s propagation speed. Sensitivity tests using smoothed wind speed or thermodynamics (i.e., air temperature, relative humidity, and sea surface temperature) to compute latent heat flux show wind speed variability explains most of the latent heat flux variability on intraseasonal timescales. A similar conclusion is found via linearization of the latent heat flux formula. Additional analysis shows mesoscale and synoptic scale wind variability have negligible impact on intraseasonal latent heat flux anomalies.
収録刊行物
-
- 気象集誌. 第2輯
-
気象集誌. 第2輯 93A (0), 1-20, 2015
公益社団法人 日本気象学会
- Tweet
キーワード
詳細情報 詳細情報について
-
- CRID
- 1390282681480151680
-
- NII論文ID
- 130005120369
-
- NII書誌ID
- AA00702524
-
- ISSN
- 21869057
- 00261165
-
- NDL書誌ID
- 027001557
-
- 本文言語コード
- en
-
- データソース種別
-
- JaLC
- NDL
- Crossref
- CiNii Articles
-
- 抄録ライセンスフラグ
- 使用不可