The rate of warming of the Arctic surface temperature has exceeded that of the global surface temperature in recent decades. However, the underlying process and causes of the long-term warming remain uncertain. In this paper, we explored the factors underlying variation in Arctic mean surface temperature anomalies (AMTA) using a piecewise linear model for 1920–2018. This analysis indicated that the change in AMTA during the study period could be divided into three segments, with AMTA increasing from 1920 to 1938, declining from 1939 to 1976, and finally increasing rapidly after 1977. By a newly developed rigorous formalism of information flow, we found a one-way causality from the driving forces to AMTA. Moreover, the AMTA evolution could mainly be attributed to a combined effect of anthropogenic and natural factors (e.g., CO_2, aerosol, and PDO). During the first warming stage (1920–1938), the PDO and aerosols are the main factors determining the change in AMTA. During the second warming stage (1977–2018), greenhouse gases, dominated by CO₂, are the major factors accounting for the Arctic warming. In 1939–1976, the observed cooling may be associated with aerosols, clouds, and land use. A better understanding of the driving mechanism underlying AMTA evolution provides insight into the historical Arctic climate change, and can improve the prediction of future changes in AMTA.

近几十年来，北极表面温度的升温速度已经超过了全球表面温度的升温速度。但是，长期变暖的潜在过程和原因仍然不确定。在本文中，我们使用1920–2018年的分段线性模型探索了北极平均表面温度异常（AMTA）变化的潜在因素。此分析表明，研究期间AMTA的变化可分为三个部分，其中AMTA从1920年到1938年增加，从1939年到1976年下降，并最终在1977年之后迅速增加。通过新近发展的严格的信息流形式主义，我们发现从驱动力到AMTA的单向因果关系。而且，AMTA的发展可能主要归因于人为因素和自然因素（例如，CO_2，气雾剂和PDO）。在第一个变暖阶段（1920-1938年），PDO和气溶胶是决定AMTA变化的主要因素。在第二个变暖阶段（1977-2018年），以CO ₂为主的温室气体是造成北极变暖的主要因素。在1939年至1976年，观测到的降温可能与气溶胶，云层和土地利用有关。更好地了解AMTA演变的驱动机制，可以深入了解北极的历史气候变化，并可以改善对AMTA未来变化的预测。