The sea surface temperature (SST) in the tropical Indian Ocean(IO) has experienced rapid warming over the past 40 years. The reason for this phenomenon is still debated. Our study suggests that the decrease in Arctic sea ice during winter can influence the warming of SST in the Northern Indian Ocean (NIO) through three main pathway including atmospheric circulation, western Pacific SST and Tibet Plateau land. Firstly, the reduction of Arctic sea ice can trigger atmospheric teleconnection wave trains and circulation anomalies from the North Atlantic to the NIO, leading to anticyclone anomaly in the Bay of Bengal(BOB) that increases thermal contribution by radiation warming, as well as cyclonic anomalies in the Arabian Sea(AS) that increases dynamic contribution by warm current transport. Secondly, the reduction of Arctic sea ice can induce a wave train propagating from the Arctic through Eurasia to the western Pacific, resulting in anticyclone anomalies and SST rise in the South China Sea, thus enhancing the dynamic contribution of heat transfer through the Indonesian through flow(ITF). Thirdly,Arctic sea ice can enhances cross-equatorial flow by inducing warm surface temperature of the Tibetan Plateau.These three pathways will still exist until 2045 in future SSP245 emission scenarios.This study establishes a connection between the Arctic and the tropical IO, expanding our understanding of the relationship between these regions.

中文翻译：

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北极海冰减少加剧了北印度洋的变暖


热带印度洋 （IO） 的海表温度 （SST） 在过去 40 年中经历了快速变暖。这种现象的原因仍在争论中。研究表明，冬季北极海冰的减少可通过大气环流、西太平洋海温和青藏高原陆地 3 种主要途径影响北印度洋 （NIO） 海温的变暖。首先，北极海冰的减少会触发从北大西洋到蔚来的大气遥相关波序列和环流异常，导致孟加拉湾的反气旋异常 （BOB） 增加辐射变暖的热贡献，以及阿拉伯海的气旋异常 （AS） 增加暖流传输的动力贡献。其次，北极海冰的减少会诱发波列从北极穿过欧亚大陆传播到西太平洋，导致南海出现反气旋异常和 SST 上升，从而增强通过印度尼西亚直通流 （ITF） 的热传递的动态贡献。（3）北极海冰通过诱导青藏高原温暖的地表温度来增强跨赤道流动，在未来的 SSP245 排放情景中，这三条路径将一直存在到 2045 年。这项研究在北极和热带 IO 之间建立了联系，扩大了我们对这些地区之间关系的理解。