Large Puna evaporation ponds associated with domain-scale atmospheric changes

Large evaporation ponds in the high-altitude Argentine Puna are associated with warmer, drier near-surface conditions across an impact domain, according to a study that applied a Before–After–Control–Impact framework to reanalysis-based meteorological data. The analysis estimated a differential air-temperature change of +0.55 °C, a 2.7-percentage-point decrease in relative humidity and a 0.73 °C decrease in dew point temperature when the pond-containing domain was compared with a nearby control domain. Vapor pressure deficit increased by 0.033 kPa, near-surface soil moisture decreased by 0.0069 m³ m⁻³, and FAO-56 reference evapotranspiration rose by 0.0036 mm h⁻¹.

The 95% bootstrap confidence intervals for all six differential changes excluded zero. The observational comparison covered the austral winter periods of 2010–2014 and 2019–2023. One domain contained extensive lithium brine evaporation-pond systems, while the other served as a nearby control.

By comparing changes in both domains over the two periods, the BACI design sought to distinguish a response associated with the more extensively developed pond systems from changes occurring across the wider region. The study examined the atmospheric consequences of extensive surface modification in a high-altitude arid environment, where the effects of evaporation ponds had received less attention than their hydrological and geochemical impacts. Uncertainty in the estimated responses was evaluated with a hierarchical moving-block bootstrap that accounted for the multi-year structure of the data and short-term serial dependence.

In the impact domain, the differential shifts toward higher temperature, lower humidity, greater vapor pressure deficit and increased reference evapotranspiration were statistically distinguishable from zero. The soil-moisture estimate provided a corresponding surface-level signal, registering a decrease in the cubic metres of water per cubic metre of soil. The response was not uniform across every variable examined.

Precipitation, low-level cloud cover, 10-m wind speed and shortwave radiation showed no clear differential response between the impact and control domains. The results therefore do not show that the ponds changed every measured aspect of the atmosphere. Instead, they identify a more specific domain-scale pattern involving near-surface temperature, humidity, soil moisture and evaporative demand.

The comparison also concerns relative changes against a nearby control area, rather than an estimate of the total atmospheric effect attributable to the ponds. Published in Theoretical and Applied Climatology in 2026, the findings support an association between more extensive evaporation-pond development and measurable atmospheric changes at the study-domain scale. The authors cautioned that the resolution of the reanalysis data precludes attributing fine-scale gradients or responses to individual facility features.

The results consequently do not establish that a particular pond caused a specific local effect. They instead demonstrate the potential of temporally structured BACI analysis for assessing atmospheric responses to major land-surface modifications in data-scarce, high-altitude environments.

Subject of Research: Domain-scale atmospheric changes associated with large evaporation ponds in Argentina’s high-altitude Puna

Article Title: Near-surface atmospheric response to large evaporation ponds in the high-altitude puna plateau: a BACI-based analysis

Article References: Abraham, J. A. (2026). Near-surface atmospheric response to large evaporation ponds in the high-altitude puna plateau: a BACI-based analysis. Theoretical and Applied Climatology, 157(11), 742. https://doi.org/10.1007/s00704-026-06693-y

Image Credits: AI Generated

DOI: 10.1007/s00704-026-06693-y

Keywords: lithium brine, evaporation ponds, Argentine Puna, atmospheric response, BACI analysis, reanalysis data, air temperature, relative humidity, evaporative demand, high-altitude climate, Near-surface, atmospheric