Conducive circulation patterns and transport mechanisms for spring dust from Taklimakan Desert to the Tibetan Plateau
Аннотация
• Three circulation patterns influence spring Taklimakan Desert (TD) dust storms. • Northwest high-pressure pattern brings TD dust to the northeastern Tibetan Plateau (TP). • Central TP receives TD dust in the northern high-pressure with warm anomaly pattern. • TD dust rises and transports to the TP due to dynamic, thermal, and terrain effects. Dust aerosols have an impact on both public health and environmental health. The Taklimakan Desert (TD) serves as a significant source of high-altitude airborne dust over the Tibetan Plateau (TP). However, systematic understanding of its transport mechanism requires further exploration beyond isolated case studies. This study effectively identified the atmospheric circulation patterns and transport mechanisms that facilitate airborne dust movement from TD to TP in the spring, utilizing an obliquely rotated principal component analysis alongside various reanalysis and satellite datasets. The findings indicate that out of the five identified circulation patterns, three — specifically the northwest high-pressure (NWH), the northern high-pressure with warm anomaly (NH-W), and the northern high-pressure with cold anomaly (NH-C) — favor the occurrence of dust storms in the TD. In the NWH and NH-W patterns, dust is transported to the northeastern TP and the northwestern and central TP as a result of the interaction between dynamic, thermal, and terrain factors. This process features an elevated boundary layer, increased temperature, a steeper temperature lapse rate, and a more significant surface sensible heat flux in the TD. In contrast, the NH-C pattern restricts dust transport due to the presence of downdrafts along the north slope of the TP, and a reduced boundary layer and stable temperature stratification in the TD. This research provides valuable insights into the crucial function of atmospheric circulation in transporting dust from TD to TP, which is beneficial for assessing the condition of the cryosphere and developing environmental protection strategies.