利用1958~2003年对流层相对湿度和风场(NCEP/NCAR再分析资料)的季节变化来定义盛行风的季节变化引起的天气气候明显变化的区域——季风区。通过分析表明,对流层低层的风场季节变率可以描述传统的季风区,但是在传统季风区以外,也有风场季节变率大的区域。利用中高层相对湿度的显著季节变化(热带地区季节变化大于20%,副热带地区大于10%,赤道地区以风向的季节变化大于90°)可以弥补风场季节变率的不足。由它们二者确定的季风区物理意义明确,有较大的合理性。
NCEP/NCAR reanalysis wind and relative humidity data from 1953 to 2003 are used to partition classical monsoon regions-the regions where changes of prevail wind induce prominent anomalies in weather and climate. Analysis indicates that seasonal variability of wind would be able to describe classical monsoon,but it introduces generalized regions. Significant seasonal variations of relative humidity in the middle-upper tropdsphere are developed to eliminate the lack of seasonal variability of wind. Significant seasonal variations refer to changes larger than 20%, 10% in tropics and subtropics,respectively. And in equatorial region, seasonal variation of relative humidity is not taken into account. It seems more reasonable to use both of them to partition the classical monsoon regions.