暖域レインバンドの成因と発達機構
The initiation and development mechanism of warm sector rainbands

大気物理学研究室 増田 有俊
指導教官: 守田 治



A two-dimensional , nonhydrostatic and primitive-equation model is used to investigate the initiation and development mechanism of warm sector rainbands. Simulations were performed with the horizontal resolution of 2km and the vertical resolution of 250m. The initial state was started from the two-dimensional Eady type baroclinic disturbance.

The important results about the initiation of warm sector rainbands are as follows: (1) Low level convergence generated by the downdraft produced by the precipitation from the narrow cold-frontal rainbands and the low level wind in the warm sector plays an important role to form warm sector rainbands. (2) Frontal wind systems, called katafront and anafront, develop depending on whether warm sector rainbands is formed or not. In the case of katafront, low level convergence is formed in the warm sector, because the downdraft produced by the narrow cold-frontal rainbands shifts to the warm sector side. In the case of anafront, low level convergence is not formed in the warm sector, as the strong downdraft shifts to the cold sector side.