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 km²/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.

海冰铅促进了大气与北冰洋之间的质量和能量交换。在过去的几十年中，海冰的持续变薄和海冰流动性的提高有可能改变北极地区铅分布的季节周期和年际变化，特别是在春季。但是，北极铅的长期趋势与海冰的流失仍然没有定论。需要从连续的中或高分辨率卫星观测中获得连续的铅分布数据，以获取区域或盆地尺度上的实际变化，趋势和铅特征。这项研究提出了一种改进的算法，该算法利用Terra / MODIS热图像中的温度异常来检索Beaufort海中的日常弹簧导程。我们将潜在客户地图与现有潜在客户数据集进行了比较，并通过Landsat-8图像进行了验证，表明改进的方法在识别裸露的水导线和被薄冰覆盖的冷冻导线方面提供了更好的结果。研究了2001-2020年研究期间4月潜在客户的发展情况和年际趋势。我们发现4月份铅矿区的年际趋势呈积极趋势，约为2612±1245 km² /年（置信度为90％）。在4月初，确定了较高的增长率，如果消除了云量变化的影响，增长率将降低26.4–29.2％。铅区与铅探测前的11天平均冰漂移速度密切相关，而区域压力梯度和东风对铅区的影响仅限于天气尺度，并在一周内消退。在铅面积异常大的年份，我们发现探测到的铅面积与加强Beaufort High和持续的东风驱动的冰运动增强密切相关。