Variations in Frequency and Intensity of Dust Events Crossing the Mongolia–China Border
Tana Bao, Tao Gao, Banzragch Nandintsetseg, Mei Yong, Erdemtu Jin
Abstract
In this study, we investigated the spatiotemporal variations of border-crossing dust events (DEs), including floating, blowing dust, and dust storms between Mongolia (MG) and Inner Mongolia (IM), China using the ground-based observations from 91 synoptic stations across the Mongolian Plateau during 1977-2018. We defined the intensity of DEs (progressive and recessive) depending on the dust impact area (number of stations affected by dust) by dividing them into three categories: DEs, transported dust events (T-DEs), and severe transported dust events (ST-DEs). The results revealed that during 1977-2018, the frequency of DEs in MG was two times higher than in IM. Simultaneously, the frequency of DEs (dominated by dust storms) increased in MG, whereas IM experienced a decrease in DEs (prevalent types of blowing dust). The T-DEs occurred 2.4 times higher than the ST-DEs over Mongolian Plateau. For the border-crossing DEs, transported dust storms were the dominant type. During 1977-1999, approximately 86% of DEs in IM originated from MG; however, this was decreased to 60% in the 2000s (2000-2018). The intensity of the border-crossing DEs originated from MG and the recessive T-DEs increased significantly since the 2000s, which were more significant than the progressive type.