孟加拉国夏季季风在孟加拉国夏季季风的活跃和中断时间
Zannatul Ferdoushi1, D A Quadir2, S M Quamrul Hassan3
1Department at Meteorology, University of Dhaka, Dhaka, 1000, Bangladesh.
Heliyon
|September 28, 2023
概括
这项研究使用30年降雨数据分析了孟加拉国的季风变化. 活跃的季风时期与西南风和较低的气压相关,而休息时期则显示东南风.
科学领域:
- 气象学 天气学
- 气候科学 气候科学
- 大气科学 大气科学
背景情况:
- 西南夏季季风对孟加拉国气候至关重要.
- 了解季内季风的变化是水资源管理和防灾准备的关键.
- 以前的研究集中在广泛的季风模式上,但季内变化需要详细分析.
研究的目的:
- 研究孟加拉国西南夏季季风的季内变化.
- 用观测数据和模型模拟来定义和分析活跃和破坏季风的时间.
- 调查与季风活跃期和中断期相关的同视条件.
主要方法:
- 利用了来自孟加拉国气象局 (BMD) 雨量计站的30年 (1988-2017) 的降雨数据.
- 采用了30公里分辨率的10年 (2008-2017年) 季风模拟 (五月-九月) 的天气和预报 (WRF) 模型.
- 模型模拟的降雨量,海平面压力 (SLP),850/200hPa风力和输出长波辐射 (OLR) 与TRMM,ERA5和Kalpana-1卫星数据进行了比较.
主要成果:
- 活跃的季风时期 (七月至八月) 的特点是每日降水量超过气候周期的0.5.5.
- 断裂周期被定义为每日降水量低于气候周期0.5的时期.
- 降雨量增加与西南风相关,降雨量减少与东南风相吻合.
- 与休息日相比,活动日显示出较低的输出长波辐射 (OLR) 和较低的海平面压力 (SLP).
结论:
- 孟加拉国的季节内季风变化与风向和海平面压力变化密切相关.
- 较低的OLR和SLP标志着活跃的季风条件,而较高的值则表明休息期.
- 这些发现增强了对季风动态的理解,这对区域气候研究和预测至关重要.
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