A coupled mode of cloud, atmospheric circulation, and sea ice controlled by wave-3 pattern in Antarctic winter: Data

This study examines coupled relationships among clouds, atmospheric circulation, and sea ice in Antarctic winter. We find that the wave-3 pattern dominates the leading co-variability mode among cloud, atmospheric circulation, and sea ice. In the mid-troposphere, the pressure, meridional wind, and clouds form a coupled wave-3 pattern. Both horizontal transport and vertical motion contribute to cloud formation, resulting in maximum cloud anomalies spatially between maximum meridional wind and pressure anomalies. The radiative effect of the cloud pattern can generate 12-cm sea ice anomalies in one month in the Amundsen Sea. It also strengthens the sea ice anomalies that are directly induced by low-level atmospheric circulation anomalies. In contrast, the radiative forcing of anomalous clouds in the lower troposphere is suppressed by the dynamic and thermodynamic effects of the circulation anomalies. These discoveries provide a better understanding of Antarctica’s interactive processes, and also offer physical evidence for climate model validations.