Distinct evolutions of haze pollution from winter to the following spring over the North China Plain: role of the North Atlantic sea surface temperature anomalies

Abstract

Abstract. This study reveals that haze pollution (HP) over the North China Plain (NCP) in winter can persist to the following spring during most years. The persistence of haze pollution over the NCP (HPNCP) is attributed to the maintenance of an anticyclonic anomaly (AA) over northeast Asia and southerly wind anomalies over the NCP. Southerly wind anomalies over the NCP reduce surface wind speed and increase relative humidity, which are conducive to above-normal HPNCP both in winter and spring. However, there exist several years when above-normal HPNCP in winter are followed by below-normal HPNCP in the following spring. The reversed HPNCP in winter and spring in these years is due to the inverted atmospheric anomalies over northeast Asia. In particular, AA over northeast Asia in winter is replaced by a cyclonic anomaly (CA) in the following spring. The resultant spring northerly wind anomalies over the NCP are conducive to below-normal HPNCP. These two distinctive evolutions of HPNCP and atmospheric anomalies over northeast Asia from winter to spring are attributed to the different evolutions of sea surface temperature anomalies (SSTAs) in the North Atlantic. In the persistent years, warm North Atlantic SSTAs in winter persist to the following spring via a positive air–sea interaction process and induce a negative spring North Atlantic Oscillation (NAO)-like pattern, which contributes to the AA over northeast Asia via an atmospheric wave train. By contrast, in the reverse years, cold SSTAs in the North Atlantic are maintained from winter to spring, which induce a positive spring NAO-like pattern and lead to a CA over northeast Asia via an atmospheric wave train. Hence, this study improves our understanding of the characteristics of haze pollution evolution from winter to the following spring and suggests the potential role of North Atlantic SSTAs to serve as an important preceding signal for haze pollution prediction one season ahead over the North China Plain.