Photo taken on Dec. 8, 2019 shows a television tower shrouded by heavy fog in Tashkent, Uzbekistan. Many flights were delayed due to the heavy fog on Sunday in Tashkent. (Photo by Zafar Khalilov/Xinhua)

Vehicles run on a road shrouded by heavy fog in Tashkent, Uzbekistan, Dec. 8, 2019. Many flights were delayed due to the heavy fog on Sunday in Tashkent. (Photo by Zafar Khalilov/Xinhua)

Vehicles run on a road shrouded by heavy fog in Tashkent, Uzbekistan, Dec. 8, 2019. Many flights were delayed due to the heavy fog on Sunday in Tashkent. (Photo by Zafar Khalilov/Xinhua)