Two pathways of how remote SST anomalies drive the interannual variability of autumnal haze days in the Beijing–Tianjin–Hebei region, China
Year: 2019
Type: article
Abstract: . Analogous to the circumstances in wintertime, the increasing severity of autumnal haze pollution over the Beijing–Tianjin–Hebei (BTH) region may also lead to impairment of the socioeconomic development and human health in this region. Despite manmade aerosol emissions, the interannual variability of autumnal (September–October–November) haze days (AHD) in the BTH region (AHDBTH) is apparently tied to the global and regional meteorological anomalies. The present study suggests that an above-normal AHDBTH is closely associated with the simultaneous sea surface temperature (SST) warming in two regions [over the North Atlantic subtropical sector (R1) and over the western North Pacific sector (R2)]. When the autumnal SST warming in R1 and R2 are both remarkably significant, the joint impacts can greatly enhance the likelihood of a higher AHDBTH. Observational and simulation evidence suggests that SST anomalies can affect the variation in AHDBTH via two different pathways. Firstly, SST warming in R1 can induce a downstream mid-latitudinal Rossby wave train, leading to a barotropic high-pressure and subsidence anomaly over the BTH region. Secondly, SST warming in R2 can also result in air subsidence over the BTH region through an anomalous local meridional cell. Through these two distinct pathways, localized meteorological circumstances conducive to a higher AHDBTH (i.e., repressed planetary boundary layer, weak southerly airflow, and warm and moist conditions) can be established.
Authors: Jing Wang, Zhiwei Zhu, Li Qi, Qiaohua Zhao, Jinhai He, Julian X. L. Wang
Language: English
Subfield: Global and Planetary Change
Field: Environmental Science
Domain: Physical Sciences
SDG: Climate action
Open Access status: gold
Estimated APC paid: $1,725
OpenAlex ID: W2899954385