The climate of Central America is influenced by changing conditions in both the North Atlantic region and the tropical Pacific Ocean, and how these systems have varied in the past to affect precipitation patterns in the tropics is poorly understood.
Our ability to predict future changes in water resource availability requires a longer-term perspective based on the geologic record. In this paper, Nathan D. Stansell and colleagues analyze lake sediments from Nicaragua for their oxygen isotopic composition in order to infer past changes precipitation during the last ~1,400 years.
This record is the first of its kind from Nicaragua that documents abrupt environmental changes at a resolution sufficient for comparing with other regional paleoclimate archives. In this region of the northern tropics, the Medieval Climate Anomaly was consistently wet, and the Little Ice Age was relatively dry.
Based on what is known about modern conditions, these findings further suggest that changes in mean-state conditions of the both ocean basins operated differently in the past to affect the climate of Central America.
Consequently, climate models that evaluate changes in water resources for this region need to consider that the modern analogue might not be consistent with what has operated on longer time-scales in the past.
Nathan D. Stansell et al., doi: 10.1130/G33736.1