Causes of 2022 Pakistan flooding and its linkage with China and Europe heatwaves

Abstract In boreal summer of 2022, Pakistan suffered from record rainfall that led to severe flooding and left more than 30 million people homeless. At the same time, heatwaves persisted over central China and Europe. The concurrence of these extreme events suggests a possible linkage. Our analysis of climatic data indicated that the record rainfall was mainly induced by compounding factors, including 1) an unusually strong anomalous easterlies associated with La Niña over the northern Indian subcontinent and intense southerlies, further enhanced by an upward trend, from the Arabian Sea, 2) extratropical-tropical interaction between the northerly, downstream of the Europe blocking, and the southerly monsoon flow from the Arabian Sea. Wave activity flux analysis and regression analysis indicated that the Europe blocking, flooding in Pakistan, and heatwave in China were teleconnected by a stationary Rossby wave-like pattern, which was distinctly different from the Scandinavian and Circumglobal teleconnection pattern and appeared to be a new teleconnection pattern. The nature of teleconnected extreme events is a newly emerged issue that warrants further in-depth investigation for better understanding.