Intraseasonal rainfall variability in North Sumatra and its relationship with Boreal Summer Intraseasonal Oscillation (BSISO)

3rd International Symposium on LAPAN-IPB Satellite For Food Security and Environmental Monitoring 2016

地球科学;轻工业;生态环境科学

Faqih, Akhmad^1 ; Nurussyifa, Desiana^1

Department of Geophysics and Meteorology, Faculty of Mathematics and Natural Sciences, Bogor Agricultural University (IPB), Kampus IPB Dramaga, FMIPA Building, Jalan Raya Dramaga, Jawa Barat, Wing 19, Bogor

16680, Indonesia^1

关键词: Boreal summer intraseasonal oscillation;    Climate variability;    Composite analysis;    Extreme rainfall;    Northern Hemispheres;    Rainfall anomaly;    Rainfall variability;    Standard deviation;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/54/1/012033/pdf
DOI  :  10.1088/1755-1315/54/1/012033

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

The Boreal Summer Intraseasonal Oscillation (BSISO) is a mode of climate variability on intraseasonal timescales that dominantly occurs during Northern Hemisphere summer monsoon. Its propagation and activity can be monitored by using indices namely as BSISO1 and BSISO2. The rainfall anomalies and extremes in North Sumatra may be potentially affected by BSISO due to its location within the path of their propagations. This study analyzes the relationship of BSISO with daily rainfall anomalies and extremes during different phases and types of BSISO. The results of spectral analysis show some agreements in the periodicity of BSISO1 and BSISO2 with daily rainfall anomaly. This study also identifies extreme rainfall during different phases of BSISO, showing the increase in the number of extreme rainfall events. High number of extreme rainfall events beyond thresholds at 90thand 95thpercentiles are mostly found during phase 1, 2 and 3 of BSISO1 and phase 1 and 2 of BSISO2. Composite analysis conducted separately for spatial standard deviations of daily rainfall anomalies are also performed in this study. Similar results are found, where BSISO influences on rainfall variability especially during phase 1, 2 and 3 of BSISO1, and phase 1 and 2 of BSISO2.