Increasing monsoon precipitation extremes in relation to large-scale climatic patterns in Pakistan

• Published in: Atmospheric Research
• Main Authors: Hussain, Azfar, Hussain, Ishtiaq, Rezaei, Abolfazl, Ullah, Waheed, Lu, Mengqian, Zhou, Jinxing, Guan, Yinghui
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier Ltd 2024
• Subjects: Atlantic and Pacific variability; Climate change; Global teleconnections; Integrated indices; Monsoon extremes; Wavelet analysis; Indian; Kendall; Pacific; Soi; North Atlantic; North Atlantic oscillation
• Online Access: http://repository.hkust.edu.hk/ir/Record/1783.1-140544; https://doi.org/10.1016/j.atmosres.2024.107592; http://lbdiscover.ust.hk/uresolver?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rfr_id=info:sid/HKUST:SPI&rft.genre=article&rft.issn=0169-8095&rft.volume=&rft.issue=&rft.date=2024&rft.spage=&rft.aulast=Hussain&rft.aufirst=Azfar&rft.atitle=Increasing+monsoon+precipitation+extremes+in+relation+to+large-scale+climatic+patterns+in+Pakistan&rft.title=Atmospheric+Research; http://www.scopus.com/record/display.url?eid=2-s2.0-85199400151&origin=inward; http://gateway.isiknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=LinksAMR&SrcApp=PARTNER_APP&DestLinkType=FullRecord&DestApp=WOS&KeyUT=001281928200001

This study comprehensively evaluates monsoon variability and its large-scale drivers in Pakistan, a country often affected by extreme monsoon events leading to destructive flooding. Utilizing the Monotonic Mann-Kendall and Sen's Slope test, we analyzed trends in seven indicators of extreme precipitation events (EPEs) from 1961 to 2017 across Pakistan and its homogeneous climatic regions. The wavelet coherence method further allowed us to probe the connection between EPEs and key climate indices such as the Atlantic Multidecadal Oscillation (AMO), North Atlantic Oscillation (NAO), El Niño–Southern Oscillation (ENSO), Indian Ocean Dipole (IOD), Pacific Decadal Oscillation (PDO), Indian summer monsoon (ISM), and Southern Oscillation Index (SOI) in the time-frequency domain. Our findings indicate a significant increase in all EPEs across Pakistan, particularly in the monsoon region (R-II) from 1961 to 2017, with a noticeable decline post-1980s. The findings revealed a significant increase in EPEs in the whole country from 1961 to 1989 to 1990–2017, with a dominant change in the monsoon region during 1990–2017. In terms of climate indices combinations, IOD + ISM showed the highest coherences (>0.65), while ENSO+IOD + ISM and ENSO+IOD + PDO displayed coherences >0.81 and > 0.79, respectively, across the entire country. The multi-linear regression (MLR) model analysis drivers indicate that IOD and ENSO are the leading drivers of changes in monsoon EPEs in the whole country, whereas the core monsoon region of Pakistan also showed a strong influence from AMO and NAO in tandem with ENSO and IOD. The overall increase in EPEs over Pakistan are mainly associated with the indices from the Pacific Ocean, especially IOD, ENSO and PDO and with their various combinations. Our study reveals the variations in EPEs across Pakistan, yielding insights that could inform water resource management strategies and disaster prevention measures. © 2024