The NOAA IR serves as an archival repository of NOAA-published products including scientific findings, journal articles, guidelines, recommendations, or other information authored or co-authored by NOAA or funded partners.
As a repository, the NOAA IR retains documents in their original published format to ensure public access to scientific information.
i
Circulation Factors Determining the Propagation Speed of the Madden–Julian Oscillation
-
2020
-
-
Source: Journal of Climate, 33(8), 3367-3380
[PDF-1.88 MB]
Details:
-
Journal Title:Journal of Climate
-
Personal Author:
-
NOAA Program & Office:
-
Description:The eastward propagating Madden–Julian oscillation (MJO) events exhibit various speeds ranging from 1 to 9 m s−1, but what controls the propagation speed remains elusive. This study attempts to address this issue. It reveals that the Kelvin wave response (KWR) induced by the MJO convection is a major circulation factor controlling the observed propagation speed of the MJO, with a stronger KWR corresponding to faster eastward propagation. A stronger KWR can accelerate the MJO eastward propagation by enhancing the low-level premoistening and preconditioning to the east of the MJO deep convection. The strength of the KWR is affected by the background sea surface temperature (SST). When the equatorial central Pacific SST warms, the zonal scale of the Indo-Pacific warm pool expands, which increases the zonal scale of the MJO, favoring enhancing the KWR. This effect of warm-pool zonal scale has been verified by idealized experiments using a theoretical model. The findings here shed light on the propagation mechanism of the MJO and provide a set of potential predictors for forecasting the MJO propagation.
-
Keywords:
-
Source:Journal of Climate, 33(8), 3367-3380
-
DOI:
-
ISSN:0894-8755;1520-0442;
-
Format:
-
Publisher:
-
Document Type:
-
Funding:
-
Rights Information:Other
-
Compliance:Library
-
Main Document Checksum:
-
Download URL:
-
File Type:
