Spatiotemporal patterns of midlatitude environmental impact variability and associated tropical thermal forcing

Gaining insight into how large-scale air–sea interactions influence environmental impact variability in tropical and extratropical regions is essential for improving climate forecasting and impact assessment. This study examines the link between the El Niño–Southern Oscillation (ENSO) and environmental impact variables (EIVs) across the Southeast of US climate regions. Using spatial coherence and temporal consistency analyses over a two-year ENSO cycle, three core regions were identified: North Region (NR), Middle Region (MR), and South Region (SR), with SR showing the strongest response to both warm and cold ENSO phases. During El Niño (La Niña) years, EIV composites were above (below) normal from winter through spring. Spatial coherence rates for El Niño ranged from 0.92 to 0.98 and for La Niña from 0.85 to 0.98, while temporal consistency rates ranged from 0.76 to 0.83 and 0.77 to 0.82, respectively. Composite-harmonic analysis further revealed that EIV anomalies often reverse between ENSO phases, with positive anomalies during warm phases showing stronger and more coherent responses. These findings underscore ENSO’s significant influence on the southeastern U.S., highlighting a strong teleconnection between large-scale climate circulation and regional environmental impact variability.