Collaborative Research: Untangling the Changing Nature of El Niño-Southern Oscillation (ENSO)-Driven Terrestrial Impacts

North Carolina State University, Raleigh NC

Investigators

Abstract

El Niño is primarily identified by a large pool of warmer-than-average water in the tropical Pacific Ocean that persists for several months in a row. El Niño, and its cooler-than-average counterpart La Niña, affects global weather and climate by altering atmospheric circulation patterns. El Niño can be predicted several months in advance, and so can provide an early picture of expected weather and climate patterns over North America and other highly populated regions of the world. It is not yet clear how El Niño will change in a future climate, with some studies suggesting it will get stronger, weaker, more or less frequent, or even that El Niño will become more frequent while La Niña diminishes, and so on. Additionally, there is uncertainty about how the future climate, which is expected to be warmer and wetter, will alter El Niño impacts. This study uses a sophisticated computer model simulation of the global atmosphere and ocean to untangle these interactions and understand how different possible changes in El Niño in turn lead to changes in their impacts. For example, if future El Niño events are stronger than current ones, how do temperature and precipitation patterns over North America change in a future climate? The investigators will systematically test several potential scenarios, uncovering the physical mechanisms that cause the changes in impacts. This study also seeks to understand if El Niño impacts may become more predictable, or less predictable, depending on how El Niño changes in the future. The outcomes of this study will contribute to our understanding of how El Niño affects North American weather and climate patterns and what can be expected under climate change. The broader impacts of this work are centered in four areas. Integration of Research and Education: The proposed work will train two graduate students and results will be integrated into classroom materials. Public Outreach: Public outreach will be facilitated through the National Oceanic and Atmospheric Administration’s climate.gov blog about El Niño. Societal Impacts: Under the current climate, El Niño’s impacts are far-reaching and highly impactful. The proposed work will contribute to improved understanding of the uncertainty in seasonal climate forecasts through a greater understanding of variability contingent on El Niño statistics and climate change. Data use beyond the lifetime of this project: The output generated via the proposed experiments will be useful not only for El Niño applications, but also for understanding how other climate variability is modulated by El Niño and future mean state changes. The investigators will share data with interested groups to support such efforts. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.