Dr. Yunhe Wang and Dr. Haibo Bi et al of  Institute of Oceanology, Chinese Academy of Sciences, and Prof. Xiaojun Yuan of Columbia University, achieved further progress in impacts on summer sea ice of winter cloud in the Antarctic. The research was published online in the Journal of Geophysical Research - Atmospheres on April 1, 2019.

The results show that the negative cloud-fraction anomalies in winter 2011 related to the large-scale atmospheric circulation resulted in a substantial negative surface-radiation budget, which cooled the surface and promoted more sea-ice growth. The sea-ice growth anomalies due to the negative cloud forcing propagated by sea-ice motion vectors from September 2011 to January 2012. The distribution of the sea ice anomalies corresponded well with the sea-ice concentration anomalies in February 2012 in the Weddell Sea and eastern Somov Sea. Thus, negative cloud-fraction anomalies in winter can play a vital role in the following summer sea ice distribution.  The results can help us to understand the thermodynamic effects of clouds on sea ice cover in the Antarctic.

Figure 1. The 850-hPa (a) geopotential height anomalies, wind anomalies, (b) air temperature anomalies, (c) specific humidity anomalies, (d) vertical pressure velocity anomalies in July 2011.

Figure 2. (a) Sea-ice growth estimated by surface cloud forcing anomalies during winter (Jun-Aug) 2011. The blue lines represent the SIE in February 2012, and the black lines represent the SIE in February 2011. (b) SIT anomaly distribution modified by the sea-ice motion from September 2011 to January 2012. (c) SIC anomalies in February 2012. (d) The difference in SIT between September 2011 and September 2010.