关键词: 科尔沁沙地, 冷锋, 风况

Abstract: Based on hourly wind records of 13 weather stations in early May, 2014, the authors analyzed and discussed the primary tempo-spatial characteristics of ground wind regimes in the Horqin Sandy Land when typical cold fronts passed. The results showed that: (1) Controlled by troughs at high altitudes and ground low pressure, instantaneous velocity can increase quickly up to more than 10 m·5s^-1 in 8 hours, and the direction turns to NW when a cold front passes over; (2) Along the prevailing wind direction, the speed of front advance attained 12.5 m·5s^-1 in the upwind grassland, while 9.21 m·5s^-1 in the sandy land, which the speed is varied with different locations; (3) With regard to the maximum entropy spectra of wind velocity, the largest value occurred to Linxi, and the smallest to Kezuohou Bannar;(4) There seem to be remarkable cycles of 2 h and 4 h, and somewhat 10 h and 25 h in Sandy Land and mountains, whereas the cycles of strong wind induced by cold fronts are not obvious; (5) Constant and frequent strong winds caused by cold fronts not only modify significantly morphology of dunes and drive robustly dune advance, but also sculpture and sustain spatial patterns of dunefields in the vast region.

Key words: Horqin Sandy Land, cold front, wind regime