How volcanic eruption latitudes diversify surface climate responses

• Main Authors: Paik, Seungmok, Min, Seung-Ki, Son, Seok-Woo, An, Soon-Il, Kug, Jong-Seong, Yeh, Sang-Wook
• Format: Text
• Language: English
• Published: 2022
• Subjects: Arctic; Pacific
• Online Access: https://doi.org/10.5194/acp-2022-187; https://acp.copernicus.org/preprints/acp-2022-187/

This study analyzes the influence of tropical, northern, and southern volcanic eruptions on the surface climate, focusing on the role of El Niño–Southern Oscillation and stratospheric polar vortex, using large-ensemble simulations of the Community Earth System Model Last Millennium Ensemble. Typically, volcanic eruptions at different latitudes induce El Niño-like sea surface temperature anomalies over the equatorial eastern Pacific. However, the temporal variations and intensities differ. Such El Niño-like responses tend to amplify summer monsoon drying, which is stronger when followed by tropical eruptions than after northern and southern eruptions. Additionally, volcanic eruptions generate a stronger stratospheric polar vortex of varying magnitudes in both hemispheres. The strengthened Arctic polar vortex that occurs after tropical and southern eruptions, accompanies a positive Arctic Oscillation response in boreal winter. This induces warmer and wetter surface conditions over northern Eurasia relative to the conditions before the eruptions. However, the Arctic polar vortex and associated surface responses are only weakly influenced by northern eruptions. This is consistent with the more poleward spread of volcanic aerosols and the reduced equatorward extension of planetary wave propagation in the lower stratosphere. These results suggest that volcanic eruptions modulate surface climate by warming the sea surface temperature over the equatorial eastern Pacific and strengthening the stratospheric polar vortex but with diverse patterns depending on eruption latitudes.