Photo taken on Jan. 18, 2020 from an Alaska Airlines plane shows the scenery of San Francisco, the United States. (Xinhua/Wu Xiaoling)

Photo taken on Jan. 18, 2020 from an Alaska Airlines plane shows the scenery amid the clouds. (Xinhua/Wu Xiaoling)

Photo taken on Jan. 18, 2020 from an Alaska Airlines plane shows the scenery of a wind power plant. (Xinhua/Wu Xiaoling)

Photo taken on Jan. 18, 2020 from an Alaska Airlines plane shows the scenery of the snow-covered mountains. (Xinhua/Wu Xiaoling)

Photo taken on Jan. 18, 2020 from an Alaska Airlines plane shows the scenery of the snow-covered land. (Xinhua/Wu Xiaoling)