Publications

Qu, M; Pang, XP; Zhao, X; Lei, RB; Ji, Q; Liu, Y; Chen, Y (2021). Spring leads in the Beaufort Sea and its interannual trend using Terra/MODIS thermal imagery. REMOTE SENSING OF ENVIRONMENT, 256, 112342.

Abstract
Sea ice leads promote mass and energy exchange between the atmosphere and the Arctic Ocean. The continuous thinning of sea ice and the enhanced sea ice mobility in the past decades can potentially change the seasonal cycle and interannual variability of lead distribution in the Arctic, especially during spring. However, the long-term trend in Arctic leads, associated with sea ice loss, remains inconclusive. Sequential lead distribution data from serial middle-or high-resolution satellite observations are needed to obtain realistic variation, trends, and lead characteristics on a regional or basin scale. This study proposed a modified algorithm to retrieve daily spring leads in the Beaufort Sea using temperature anomaly from Terra/MODIS thermal imagery. Our lead map was compared to existing lead datasets and validated by Landsat-8 images, showing that the modified method gave better results in identification of open water leads and refrozen leads covered by thin ice. The development and interannual trend for April leads were explored for the study period 2001-2020. We found a positive interannual trend in the April lead area of about 2612 +/- 1245 km(2)/year (90% confidence). Higher increasing rate was identified in the early April, which would be 26.4 - 29.2% lower if the influence from cloud variation was removed. Lead area presents a close correlation with the 11-day average of ice drift speed before lead detection, while the influence of regional pressure gradient and easterly wind on the lead area is limited to the synoptic scale and recedes within a week. In the years with anomalous large lead area, we found the detected lead area are closely related to enhanced ice motion driven by strengthening Beaufort High and persistent easterly wind.

DOI:
10.1016/j.rse.2021.112342

ISSN:
0034-4257