Influence of the November Arctic Oscillation on the subsequent tropical Pacific sea surface temperature

Abstract

Previous studies suggested that the variability of boreal spring Arctic Oscillation (AO) can exert a significant influence on the sea surface temperature (SST) anomalies in the Niño-3.4 region during the following winter. This study further reveals that AO in November can have a pronounced influence on the tropical central-eastern Pacific SST anomalies during the following spring and summer. When the November AO is in its positive (negative) phase, SST anomalies tend to be positive (negative) during the following spring and summer in the tropical central-eastern Pacific. The influence of the AO is accomplished by atmospheric circulation anomalies over the subtropical North Pacific through an interaction between the synoptic-scale eddy and the low-frequency mean flow. In the positive November AO years, pronounced cyclonic circulation and atmospheric heating anomalies are observed over the subtropical North Pacific. The atmospheric heating anomalies sustain westerly wind anomalies over the tropical western North Pacific through a Gill-like atmospheric response. The westerly wind anomalies extend eastward subsequently through positive air-sea feedback mechanism, and result in SST warming during the following spring and summer in the tropical central-eastern Pacific. Results of this study imply that the November AO index can be used as an effective predictor of SST anomalies in the Niño-3.4 region during the following spring and summer.

The influence of boreal spring Arctic Oscillation on the subsequent winter ENSO in CMIP5 models

“…In addition, a strong spring AO's Pacific component and associated easterly wind anomalies to its south may provide more favorable conditions for the development of spring AO-related cyclonic circulation anomalies over the subtropical North Pacific. temperature (SST) anomalies over extratropics are important in maintaining the ENSO variability (e.g., Vimont et al 2001Vimont et al , 2003Feng et al 2014;Oshika et al 2015;Nakamura et al 2015;Ding et al 2015;Chen et al 2015a). For example, Vimont et al (2003) showed that the boreal winter North Pacific Oscillation (NPO) can impact the outbreak of ENSO in the subsequent winter via the so-called "seasonal footprinting mechanism".…”

Influence of mature El Niño‐Southern Oscillation phase on seasonal precipitation and streamflow in the Yangtze River Basin, China

“…Meanwhile, AO has a significant connection with the ENSO explored in the physical process (Chen et al ., ). The spring AO‐related anomalously atmospheric circulations influencing ENSO has become a strong regime after 1970s, and the November AO phase had a positive correlation with Pacific SST anomalies (Chen et al ., , ). The significant AO‐ENSO connection outbroke through the positive Bjerknes feedback in subsequent winter (Chen et al ., ).…”

Relationship between cold winters over Northern Asia and the subsequent hot summers over mid‐lower reaches of the Yangtze River valley under global warming

“…Whether through an interaction between the synoptic-scale eddy and the low-frequency mean flow like the influence of the Arctic Oscillation (AO) on tropical central-eastern Pacific SST (Chen et al, 2015)? In addition, the reasons for interdecadal change in the relationship between the cold winters over Northern Asia and hot summers over MLYRV before and after 1985/1986 are also unclear.…”