Abstract:

A cold airflow snowstorm process on December 6-7, 2005 in the Shandong peninsula was simulated using a WRF model. By reducing the height of the Taihang mountains down to 10 m and uplifting the height of the Shandong peninsula to 500 m, a sensitivity experiment was performed to analyze the effects of topography of the Taihang mountains and Shandong peninsula on cold airflow snowstorm. The results indicate that the intensity of cold airflow snowstorm in the Shandong peninsula increases because of the existence of the Taihang mountains. The convergence intensity of 10 m wind field in the sensitivity experiment by reducing the height of the Taihang mountains is weakened obviously compared with that in the control experiment, especially in the north of the Shandong peninsula. At the same time, the convergence of flow field in the Shandong peninsula is weakened simultaneously as the stream become diverging. A wave is generated as the northwest wind at 850 hPa crosses over the Taihang mountains, and the vortex in the wave strengthens the local convergence by moving downstream to the Shandong peninsula. As the raising of height of the Shandong peninsula enhances the effects of uplifting and convergence, the cold airflow snowstorm is strengthened consequently.

Key words:  Cold airflow snowstorm, Landform, Sensitivity experiment