153 - Identifying Teleconnections for the Precipitation of Karachi, Pakistan

Karachi Pakistan is home to over 20 million residents and is already facing the impacts of climate change via flooding, heatwaves, and sea-level rise. Focusing specifically on precipitation, an important driver of change is the changes in teleconnections (that is, large-scale oceanic, atmospheric, and land surface patterns). However, Karachi is on the edge of the well-known South Asian Monsoon system, and as such, the teleconnections responsible for Karachi’s precipitation have only been minimally studied. This study aims to definitively identify Karachi’s precipitation teleconnections, and in doing so, demonstrate a rigorous approach that can be an exemplar for other regions in the global south. Using correlation and wavelet analysis, we examine candidate teleconnections in the Indian, Pacific, and Atlantic Oceans at interannual and decadal timescales. We find that the interannual variability in Karachi’s precipitation is explained by the El Nino-Southern Oscillation while the decadal variable is likely driven by the Atlantic Equatorial Mode. The outcomes of this study are informative for seasonal forecasting as well as long-term projections under climate change.