Monsoon precipitation variations in Myanmar since AD 1770: linkage to tropical ocean‐atmospheric circulations

• Published in: Climate dynamics 2021-05, Vol.56 (9-10), p.3337-3352
• Main Authors: Zaw, Zaw, Fan, Ze-Xin, Bräuning, Achim, Liu, Wenjie, Gaire, Narayan Prasad, Than, Kay Zin, Panthi, Shankar
• Format: Article
• Language: English
• Subjects: Analysis; Annual precipitation; Atmospheric circulation; Climate; Climate system; Climatic indexes; Climatology; Drought; Earth and Environmental Science; Earth Sciences; El Nino; El Nino phenomena; El Nino-Southern Oscillation event; Environmental aspects; Extreme weather; Forecasts and trends; Geophysics/Geodesy; Global climate; Hydroclimate; Influence; Monsoon circulation; Monsoon precipitation; Monsoons; Ocean circulation; Oceanography; Oceans; Periodicities; Precipitation; Precipitation variability; Precipitation variations; Reconstruction; Sea surface; Sea surface temperature; Sea surface temperature variations; Seasonal variations; Southern Oscillation; Statistical methods; Summer; Summer monsoon; Summer precipitation; Surface temperature; Tectona grandis; Temperature variations; Tree growth; Tree rings; Tropical atmosphere; Tropical circulation; Tropical climate; Variation; Weather; Wind
• ISSN: 0930-7575; 1432-0894
• DOI: 10.1007/s00382-021-05645-8

To understand inter-annual to decadal summer monsoon precipitation variations in Myanmar, we developed new tree-ring chronologies of Tectona grandis (teak) from three sampling sites in north-central Myanmar where the climatic proxy is sparse. A regional chronology (spanning 1700–2016) derived from three site chronologies showed a strongly positive precipitation sensitivity during the summer monsoon ( R  = 0.71), indicating that slow tree growth was detected in years of deficient precipitation. We reconstructed monsoon precipitation (May–October) for the period 1770–2016, with robust calibration-verification statistics. Our reconstruction revealed 22 (16) extremely dry (wet) years over the past 247 years. Several dry and wet episodes recorded in our reconstruction are consistent with other precipitation proxies from tropical Asia, such as the East Indian drought in 1790–1796 and the Victorian Holocaust drought in 1888–1890. The 2.0–4.0-year high-frequency periodicities revealed from spectral peaks and dominant regions of high spatial correlations indicated the summer precipitation in Myanmar is linked with broader-scale ocean-atmospheric circulations, mainly associated with the El Niño-Southern Oscillation (ENSO) activities due to sea surface temperature variations in the tropical Pacific Ocean. Coherent relationships of our reconstructed series with ENSO-related climate indices further support the dynamics of monsoon precipitation variability in Myanmar is inter-linked with global climate systems. Our reconstruction inferred from teak tree rings may be useful to provide valuable insight into the impacts of extreme weather events associated with monsoon hydroclimate in Myanmar.