Coastal dunefields of south Brazil as a record of climatic changes in the South American Monsoon System

- South Brazil coastal dunefields have been influenced by recent climate change.
- Meteorological data show relationships between wind direction and the climatic system.
- Intensification of the South American Monsoon System promotes dune stabilization.

Southern Brazil coastal dunefields are undergoing a stabilization process that appears to be influenced by climate change. Although this process is relatively well known in the literature, the precise climatic mechanisms involved were not fully understood until now. Here, we propose a new method for integrating meteorological data with dunefield morphology analyses by remote sensing to better understand the impacts of recent climate change on dunefield dynamics. Based on this approach, three successive morphological phases were identified for the Santa Catarina central coast dunefields since 1938: (i) increased sand saturation; (ii) reduced sand saturation with consequent accelerated dune migration; and (iii) decelerated dune migration with trends of stabilization by the vegetation cover. For the coastal dunefields of southern Brazil, the stabilization process can be explained mechanistically by an increase in precipitation and decrease of wind power, both of which were correlated with the intensification of the South American Monsoon System.