Analysis of Different ENSO Severity on the Frequency and Intensity of Marine Heatwaves in the Tropical Pacific with Ocean Niño Index and Marine Heatwave Time Series Data from 2002 to 2024

Liangtong (Sry) Wei OCEAN 215 Final Project
Autumn 2024

This research investigates the impact of El Niño-Southern Oscillation (ENSO) on marine heatwave (MHW) events in the tropical Pacific (5°N-5°S, 120°-170°W) over the past 22 years. The study aims to evaluate how stronger ENSO events influence the frequency, intensity, and spatial distribution of MHWs, with a particular focus on potential seasonal trends and temporal lags between ENSO peaks and MHW intensities. By analyzing ENSO severity categories and their relationship with MHW occurrences, this research identifies a notable increase in moderate to strong MHW events during stronger ENSO phases. Results indicate a temporal lag between ENSO peaks, characterized by Ocean Niño Index values, and subsequent MHW intensification with time series data. The clustering patterns in the visualization of MHW density and intensity alongside four ENSO peaks further solidifies this result. These key findings reveal that stronger ENSO events correlate with increased occurrences of extreme MHWs, demonstrate a lag between ENSO peaks and subsequent MHW intensities, and emphasize the significance of time-dependent analyses in understanding ENSO-MHW interactions, which suggesting further investigation into temporal dynamics and regional variability.