Late Winter Sea Ice in the Bering Sea: Predictor for Maize and Rice Production in Northeast China

Abstract

AbstractIn this research, the linkage between late winter Bering Sea ice and maize/rice yields in northeastern China (NEC) is investigated. Results show that such ice influences NEC crop production and thus can be employed to predict harvest amounts. Further investigation reveals that positive anomalies of late winter sea ice cover can persist until spring and that spring sea ice can strengthen North Pacific Oscillation (NPO) positive-phase patterns, and vice versa. NPO significantly affects sea surface temperature (SST) over the North Pacific Ocean through sea–air interaction—in particular, in the Kuroshio region—that may persist until summer. In association with the positive SST anomalies, the polar vortex weakens and the western Pacific subtropical high strengthens, resulting in the convergence of southern and northern air masses over NEC. Moreover, both the southerly flow along the western flank of the western Pacific subtropical high and the easterly flow from the Japan Sea and the central Pacific region supply more water vapor transport; thus, an anomalous water vapor convergence center appears in NEC. With the anomalous updrafts, NEC exhibits positive precipitation anomalies. The greenhouse effect of water vapor results in an increase in minimum temperature, thereby leading to a decrease in diurnal temperature range (DTR). This increase in minimum temperature and decrease in DTR are primary factors favoring increases in rice and maize yields, respectively.