摘要
Based on NCEP reanalysis data,EDAS data and ground observation data,the causes of a strong sandstorm process in Ulanqab City from March 14 to 15,2021 were analyzed.The analysis shows that"3.15"sandstorm,a sandstorm process accompanied by northwest gale behind the front,was caused by strong cold air in the north.In the early stage,the Mongolian cyclone resulted in the increase of temperature and decrease of pressure on the ground.When a strong surface cold high pressure at the rear of the cyclone invaded the city,a strong pressure gradient between high and low pressure provided dynamic conditions for the sandstorm outbreak.The transit of the surface cold front was the sign of the sandstorm outbreak,and the downward transmission of momentum at high altitudes increased the wind speed near the surface.
