A Comparison of the Effects of Interannual Arctic Sea Ice Loss and ENSO on Winter Haze Days： Observational Analyses and AGCM Simulations

• Published in: Journal of Meteorological Research Vol. 31; no. 5; pp. 820 - 833
• Main Authors: Li, Shuanglin, Han, Zhe, Chen, Huopo
• Format: Journal Article
• Language: English
• Published: Beijing The Chinese Meteorological Society 01-10-2017; Institute of Atmospheric Physics/Climate Change Research Center,Chinese Academy of Sciences,Beijing100029%Institute of Atmospheric Physics/Climate Change Research Center,Chinese Academy of Sciences,Beijing100029; Department of Atmospheric Science,China University of Geoscience,Wuhan430074
• Subjects: Atmospheric Protection/Air Quality Control/Air Pollution; Atmospheric Sciences; Earth and Environmental Science; Earth Sciences; Geophysics and Environmental Physics; Meteorology; Special Collection on the Heavy and Persistent Haze–Fog Episodes in Winter 2016 in the Beijing–Tianjin–Hebei Area of China; AGCM experiments; Arctic sea ice loss; ENSO; winter haze days
• ISSN: 2095-6037; 2198-0934
• DOI: 10.1007/s13351-017-7017-2

This study compares the impacts of interarmual Arctic sea ice loss and ENSO events on winter haze days m mare- land China through observational analyses and AGCM sensitivity experiments. The results suggest that （1） Arctic sea ice loss favors an increase in haze days in central-eastern China; （2） the impact of ENSO is overall contained within southern China, with increased （reduced） haze days during La Nifia （El Nifio） winters; and （3） the impacts from sea ice loss and ENSO are linearly additive. Mechanistically, Arctic sea ice loss causes quasi-barotropic positive height anomalies over the region from northem Europe to the Ural Mountains （Urals in brief） and weak and negative height anomalies over the region from central Asia to northeastem Asia. The former favors intensified frequency of the blocking over the regions from northern Europe to the Urals, whereas the latter favors an even air pressure distribu- tion over Siberia, Mongolia, and East Asia. This large-scale circulation pattern favors more frequent occurrence of calm and steady weather in northern China and, as a consequence, increased occurrence of haze days. In comparison, La Nifia （El Nifio） exerts its influence along a tropical pathway by inducing a cyclonic （anticyclonic） lower-tropo- spheric atmospheric circulation response over the subtropical northwestern Pacific. The northeasterly （southwesterly） anomaly at the northwestern rear of the cyclone （anticyclone） causes reduced （intensified） rainfall over southeastern China, which favors increased （reduced） occurrence of haze days through the rain-washing effect.