Abstract
In this study, the direct and indirect atmospheric responses over the Asian–Pacific–American region to the El Niño–Southern Oscillation (ENSO) are documented. Since ENSO is likely to induce the northward displacement of the East Asian trough (NDEAT), some of the influence of ENSO on the Asian–Pacific–American region is possibly indirect and acts by inducing NDEAT. To separate corresponding influences of ENSO and NDEAT, partial regression is utilized. It is noted that temperature variations in the East Asian–Western Pacific region are controlled mainly by NDEAT. In contrast, ENSO demonstrates a weak direct relation to the temperature variation over the East Asian–Western Pacific region. This suggests that the influence of ENSO on this region is indirect, through modulation of NDEAT. On the other hand, temperature variation over the tropical eastern Pacific is dominated by ENSO forcing. Finally, temperature variation over the eastern North American–Western Pacific region is controlled by both ENSO and NDEAT. Nevertheless, their influences on temperature and circulation over this region tend to offset each other. This implies that temperature variation is controlled by their relative strengths.
Highlights
The El Niño–Southern Oscillation (ENSO) is a dominant ocean and atmospheric coupling phenomenon over the tropical Pacific[1,2]
The first empirical orthogonal function (EOF) represents the northward displacements of the East Asian trough (EAT) (Fig. 1b), respectively
To delineate the impacts on different regions at seasonal and synoptic scales, we investigate the two time scales separately
Summary
The El Niño–Southern Oscillation (ENSO) is a dominant ocean and atmospheric coupling phenomenon over the tropical Pacific[1,2]. An eastward shift of the convective center over the tropical Western Pacific is associated with anomalous sea surface temperatures during El Niño winters. This changes both the zonal overturning cell (Walker cell)[3,4] and meridional overturning cell (Hadley cell)[5]. Aside from its modulation on overturning circulation, ENSO induces a Rossby wave train, originating from the tropical central Pacific and moving to North America[6,7,8,9] This shows the possible linkage of ENSO with circulation changes in remote regions. This study is carried out to examine these two types of ENSO forcing on climate variability over the Asian–Pacific–American region at both seasonal and synoptic time scales
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
