ABSTRACT

Sea ice conditions and navigability along four typical routes of the Northeast Passage (NEP) are analysed using remote-sensing data from 1979 to 2019. The influence of air temperature (T_air) and surface wind on the sea ice concentration (SIC) and the navigability of routes is determined. It is found that the annually averaged SICs of the different routes have decreased over the past 41 years. The fastest rate of decrease occurred in the Kara Sea (∼−1% per year), while the slowest rates of decrease occurred in the Laptev/East Siberian Sea (∼−0.42% per year). The number of navigable days for the Kara Sea has become ∼1–2 months longer than the Laptev/East Siberian Sea route as a result. The effect of T_air on SIC, quantified by ΔSIC/ΔT_air in the routes through the eastern Kara Sea and Laptev/East Siberian Sea in 2010s was ∼−0.04/°C, two to three times that seen during the 1980s. Air temperature is becoming a significant driving force of melting ice in these routes. Surface winds are also a crucial factor for the navigability of the Vilkitsky Strait and Long Strait, as they drive ice drift, and affect the navigability of the Kara Strait by introducing warm air.

摘要

利用1979年至2019年的遥感数据，对东北通道（NEP）四个典型路线的海冰条件和通航性进行了分析。气温（T _air）和地表风对海冰浓度（SIC）和海冰浓度的影响。确定路线的可通行性。结果发现，在过去的41年中，不同路线的年均SIC有所下降。下降最快的速度发生在卡拉海（每年约-1％），而下降最快的速度发生在拉普捷夫/西伯利亚海（每年约-0.42％）。结果，与拉普捷夫/东西伯利亚海航线相比，卡拉海的通航天数已增加了约1-2个月。的效果Ť_空气上SIC，通过ΔSIC/Δ定量Ť在2010年代，穿过东部卡拉海和拉普捷夫/西伯利亚海的航线中的_空气约为-0.04 /°C，是1980年代的两倍至三倍。在这些路线中，空气温度正在成为融化冰的重要驱动力。地表风也是导致Vilkitsky海峡和Long Strait通航的关键因素，因为它们推动冰漂移并通过引入温暖的空气影响Kara Strait的通航性。