Present-Day Patagonian Dust Emissions: Combining Surface Visibility, Mass Flux, and Reanalysis Data

• Published in: Journal of Geophysical Research: Atmospheres
• Main Authors: Cosentino, N. J., Gaiero, D. M., Lambert, F.
• Format: Article in Journal/Newspaper
• Language: English
• Published: AMER GEOPHYSICAL UNION 2024
• Subjects: aerosols; aridity; dust; Patagonia; SOURCE REGIONS; SOIL-MOISTURE; MINERAL DUST; AEOLIAN DUST; TRANSPORT; DESERT; DEPOSITION; IMPACT; MODEL; 13 Climate Action; 11 Sustainable Cities and Communities; 13 Acción por el clima; 11 Ciudades y comunidades sostenibles; Antarc*; Antarctica
• Online Access: https://repositorio.uc.cl/handle/11534/78943; https://doi.org/10.1029/2020JD034459

The magnitude of the climatic forcing associated with mineral dust aerosols remains uncertain due in part to a lack of observations on dust sources. While modeling and satellite studies provide spatially extensive constraints, they must be supported by surface-validating dust monitoring. Southern South America is the main dust source to the southern oceans (>45 degrees S), a region of low biological productivity potentially susceptible to increased micronutrient fertilization through dust deposition, as well as one of the main dust sources to Antarctica, implying long-range transport of dust from Patagonia and potentially affecting snow cover albedo. We present multiyear time series of dust-related visibility reduction (DRVR) and dust mass flux in Patagonia. We find that local DRVR is partly controlled by long-term (i.e., months) water deficit, while same-day conditions play a smaller role, reflective of water retention properties of fine-grained dust-emitting soils in low-moisture conditions. This is supported independently by reanalysis data showing that large-scale dust outbreaks are usually associated with anomalously high long-term water deficit. By combining visibility data, surface dust sampling, and particle dispersion modeling, we derive regional dust emission rates. Our results suggest that the inclusion of long-term soil hydrologic balance parameterizations under low-moisture conditions may improve the performance of dust emission schemes in Earth system models. Agencia Nacional de Promocion Cientifica y Tecnologica (ANPyCT) ANID-Fondo Nacional de Desarrollo Cientifico y Tecnologico (FONDECYT) ANID/Fondecyt ANID/Fondo de Financiamiento de Centros de Investigacion en areas Prioritarias (FONDAP) ANID/Millennium Science Initiative/Millennium Nucleus Paleoclimate