Subseasonal mode of cold and wet climate in South China during the cold season: a climatological view

Abstract

The authors investigate the dominant mode of climatological intraseasonal oscillation (CISO) of surface air temperature (SAT) and rainfall in China, and discuss the linkage of cold and wet climate in South China (SC) with the Arctic circulation regime during the cold season (from November to March). Results show that a positive CISO displays a cold-dry climate in North China, whereas a cold-wet pattern prevails in SC with a quasi-30-day oscillation during the peak winter season. In SC, the intraseasonal variability of SAT plays a leading role, altering the cold-wet climate by the southward shift of a cold front. Evidence shows that the circulation regime related to the cold and wet climate in SC is mainly regulated by a pair of propagating ISO modes at the 500-hPa geopotential height in the negative phase of Arctic Oscillation. It is demonstrated that the local cyclonic wave activity enhances the southward movement of the Siberian high, favoring an unstable atmosphere and resulting in the cold-wet climate over SC. Therefore, the cold-air activity acts as a precursor for subseasonal rainfall forecasting in SC.

The Alternating Change of Cold and Warm Extremes Over North Asia During Winter 2020/21: Effect of the Annual Cycle Anomaly

“…Arctic signals usually precede cold surges in Asia (e.g., L. Wang & Chen, 2010; Song & Wu, 2019; Song et al., 2018; Yu et al., 2019). Weakening of the stratospheric polar vortex has increased the probability of severe cold air outbreaks over Eurasia in recent global warming (e.g., Huang et al., 2021; Kretschmer et al., 2017).…”

“…Cold waves usually occur in January when the phase of annual cycle (AC) of winter SAT reaches its minimum (e.g., Yu et al., 2019). However, the slow‐varying AC of the East Asian monsoon and global temperature has shown an interannual variability and long‐term trend in phase and amplitude due to the climate natural variability and human influence (e.g., Ding & Chan, 2005; Liu et al., 2021; Santer et al., 2018; S. Jiang et al., 2020; Stine et al., 2009).…”

“…Although the cold waves were attributed to the synergistic effect of La Niña and Arctic warming (Zheng et al., 2021), no study has yet clearly addressed what signals resulted in an alternating change from cold to warm extremes over NA during the winter. The ISO of the winter circulation regime has been considered an important factor for cold waves (e.g., Song et al., 2018; L. Wang et al., 2021; Yang & Li, 2016; Yu et al., 2019). However, the impact of AC on the ISO has not yet been clearly addressed yet.…”

“…The ISO of the winter circulation regime has been considered an important factor for cold waves (e.g., Song et al, 2018;L. Wang et al, 2021;Yang & Li, 2016;Yu et al, 2019). However, the impact of AC on the ISO has not yet been clearly addressed yet.…”

Combined effect of the solar activity and ENSO on the tropical cyclone genesis frequency in the southeastern part of the western North Pacific

“…The power spectrum, Pearson correlation, linear regression, and composite analysis are used in this work, and the statistical significance is evaluated based on the Student t-test. According to Yan et al (2004) and Yu et al (2019), the effective degree of freedom of low-pass filtering is calculated.…”