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Based on ilia observational data, NCEP 1° X 1° reanalysir data and potential vortieita theory, the oeeurrenea mechanism ol a strong sandstorm occurring in Inner Mongolio duvng March 14 - 15 was studied. The resultr show that the larce potential voCex aree io the uppec troposphere moved eastward and downward, and a structure similao te a "funnel" appeared; the cyclone moved eastward and developed; the high potential vortex region always matched the region where the cyclone developed; the development ol' the cyclone was closely related to the cold air activity, and there was an obvious reteraction between high- and low-altitude systems. The potential vorle'ilv at 500 hPa had obvious significancc for the influencing system oS this sandstorm. The 0. 5 PVU contour tine can be used as the boundara oS sandstorm weatUer area. On the potential temperature profile, Wo occurrencc process oS ths sandstorm was the process oS the expansion oS cold air from high latitudes to low latitudes. When the high-value potential vortieita system slide along the isentropic surfacc, the lowee vertical vortieita increased due to the increasing slope oS the isentropic surfacc and the conservation oS potential vortieita, leading to the development oS the surfacc cyclone circulation and the enhancement oS wind speed, and furthee causing the occurrencc oS WIs sandstorm. [ABSTRACT FROM AUTHOR]

In order to explore the characteristics of climate change in the Hunshandake Sandy Land, the number of gale days, sandstorms, and extreme precipitation events in the sandy land from 1956 to 2018 were analyzed. The results show that in the Hunshandake Sandy Land, the number of gale days was the largest in spring; it first increased and then decreased from 1956 to 2018. The number of gale days was large from 1955 to 1980, and decreased in fluctuation after 1980. Sandstorms mainly occurred in spring; the number of sandstorm days first increased and then decreased. It was the largest during 1966 - 1970, and then decreased slowly; it was the smallest during 1996 -2000. with the anomaly of about -0. 16 d; it rose after the 21sl century. The threshold of extreme precipitation in the sandy land was high in the south and low in the north. The threshold exceeded 80 mm in the southern part of the sandy land, and was less than 50 mm in sandy hinterland and its northern part. The total frequency of extreme precipitation in the sandy land showed an increasing trend year by year. Especially after 1982, the frequency of extreme precipitation rose obviously. Extreme precipitation events mostly happened in July and August. The frequency of extreme precipitation events was the highest in Abaga Banner and the lowest in Duolun County. The maximum daily precipitation appeared in Duolun County, reaching 142.3 mm. [ABSTRACT FROM AUTHOR]

Based on the data of sandstorm at 11 stations in Ulanqab City from 1990 to 2021, the spatial and temporal variation characteristics of sandstorm weather were analyzed firstly, and then the conceptual models of cold front and Mongolian cyclone sandstorm were obtained by analyzing sandstorm cases. Finally, the forecast points of the two types of sandstorm weather were given to provide some scientific basis and reference for the prediction of local sandstorm weather in the future. [ABSTRACT FROM AUTHOR]