“向南方”的英语？

燕子在秋季开始向南方迁移.Swallows begin their migration south in autumn.飞机飞向南方.The airplanes winged their way to the south.例如, 撒哈拉沙漠以每年30英里的速度向南方推移.The Sahara desert, for example, creeps southward at a rate of thirty miles annually....