South American hydroclimatic response to large volcanic events over the last 600 years. A data-model intercomparison
Abstract
Volcanic eruptions constitute one of the main radiative perturbations to Earths climate system over the last centuries. Such events can induce large and persistent hydroclimatic changes at global and regional scale and yet, the magnitude and spatial extent of the hydroclimatic impacts over South America remain poorly understood. Here, we use the novel tree-ring based South American Drought Atlas (SADA) to analyze the hydroclimatic response of large volcanic events over the last 600 years during the summer season (December-February). Through a superposed epoch analysis, we investigate the hydroclimate response following tropical eruptions, larger than Mt Pinatubo, and events with hemispherically greater aerosol loading in either the Northern or Southern Hemisphere. We find a significant (p<0.05) drying over the Bolivian Altiplano following tropical eruptions and eruptions with greater aerosol loading in the Northern Hemisphere (years 0 and +1). In addition, wet conditions over the central Andes and dry conditions over central Chile and southern Patagonia are statistically significant two years after the eruption and persist for almost a decade. Finally, we compare our results with state-of-the-art data assimilation products (the Paleo Hydrodynamics Data Assimilation product-PHYDA, and the Last Millennium Reanalysis-LMR), and two paleoclimate models (NCAR Community Earth System Model-Last Millennium Ensemble, and the NASA GISS Model E2-R). The PHYDA reproduces the initial drying response over the Altiplano and the NASA GISS model shows the posterior extended wetting over the central Andes. However, none of the products reproduce either the magnitude or the extent of the hydroclimatic response seen in SADA. Reconciling these differences is therefore critical for accurately characterizing the hydroclimate risks of future volcanic eruptions over South America.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2021
- Bibcode:
- 2021AGUFMGC55C0439T