Rainfall isotopic variability in northern Central America driven by regionally-organized deep atmospheric convection and airmass rainout
5 affiliations
- 1Department of Geoscience, University of Nevada Las Vegas
- 2Department of Environmental Sciences, Informatics and Statistics, University Ca’ Foscari of Venice
- 3Department of Earth and Environmental Systems, Indiana State University
- 4Centro Universitario del Norte, Universidad de San Carlos de Guatemala
- 5Instituto Nacional de Sismología, Vulcanología, Meteorología e Hidrología
Abstract
Understanding the controls of rainfall isotopic composition (δ18Op) is essential to interpret isotopic paleoclimate records, yet it remains challenging in areas with complex climate and varied topography, such as northern Central America. Here, we present two years of daily rainfall isotope measurements from Guatemala to evaluate the regional and local climatic controls on δ18Op variability. We show that regional-scale convection and upstream rainout drive δ18Op variability and integrate multi-annual model-based δ18Op data supporting a persistent regional control across multiple timescales, from daily to interannual. Further, we document a consistent link between higher rainfall 18O depletion associated with both more intense regionally-organized convective systems and larger stratiform rain fractions. Moisture source analysis shows a dominant contribution from the Caribbean–Atlantic, and secondarily from the Mesoamerican continent, Gulf of Mexico, and Eastern Pacific. While changes between dominant source regions are associated with distinct δ18Op signatures, back-trajectory analysis and a source-based isotope reconstruction demonstrate a larger upstream airmass rainout control on the seasonal variations of δ18Op. Our results suggest that δ18Op in Guatemala rainfall are sensitive to regionally-integrated hydroclimatic processes, and that isotope-based paleoclimate records from northern Central America can provide reconstructions of past changes in regional-scale atmospheric convection and upstream rainfall amount.
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BibTeX
@article{lucia2026rainfall,
title = {{Rainfall isotopic variability in northern Central America driven by regionally-organized deep atmospheric convection and airmass rainout}},
author = {Giuseppe Lucia and Davide Zanchettin and Amos Winter and Osmín J. Vásquez and Mario Cu-Xi and Matthew S. Lachniet},
journal = {Scientific Reports},
year = {2026},
month = jul,
doi = {10.1038/s41598-026-63020-1},
url = {https://doi.org/10.1038/s41598-026-63020-1},
note = {CC BY},
}
RIS
TY - JOUR
TI - Rainfall isotopic variability in northern Central America driven by regionally-organized deep atmospheric convection and airmass rainout
AU - Giuseppe Lucia
AU - Davide Zanchettin
AU - Amos Winter
AU - Osmín J. Vásquez
AU - Mario Cu-Xi
AU - Matthew S. Lachniet
PY - 2026
DA - 2026/07/01
JO - Scientific Reports
DO - 10.1038/s41598-026-63020-1
UR - https://doi.org/10.1038/s41598-026-63020-1
AB - Understanding the controls of rainfall isotopic composition (δ18Op) is essential to interpret isotopic paleoclimate records, yet it remains challenging in areas with complex climate and varied topography, such as northern Central America. Here, we present two years of daily rainfall isotope measurements from Guatemala to evaluate the regional and local climatic controls on δ18Op variability. We show that regional-scale convection and upstream rainout drive δ18Op variability and integrate multi-annual model-based δ18Op data supporting a persistent regional control across multiple timescales, from daily to interannual. Further, we document a consistent link between higher rainfall 18O depletion associated with both more intense regionally-organized convective systems and larger stratiform rain fractions. Moisture source analysis shows a dominant contribution from the Caribbean–Atlantic, and secondarily from the Mesoamerican continent, Gulf of Mexico, and Eastern Pacific. While changes between dominant source regions are associated with distinct δ18Op signatures, back-trajectory analysis and a source-based isotope reconstruction demonstrate a larger upstream airmass rainout control on the seasonal variations of δ18Op. Our results suggest that δ18Op in Guatemala rainfall are sensitive to regionally-integrated hydroclimatic processes, and that isotope-based paleoclimate records from northern Central America can provide reconstructions of past changes in regional-scale atmospheric convection and upstream rainfall amount.
SN - 2045-2322
ER -