Appraising timing response of paleoenvironmental proxies to the Bond cycle in the western Mediterranean over the last 20 kyr

• Published in: Climate Dynamics
• Main Authors: Rodrigo Gámiz, Marta, Martínez-Ruiz, Francisca, Rodríguez Tovar, Francisco J., Pardo Iguzquiza, Eulogio, Ortega Huertas, Miguel
• Format: Other/Unknown Material
• Language: English
• Published: Springer 2021
• Subjects: Cross-spectral; Bond cycle; Western Mediterranean; Marine record; Paleoenvironmental proxies; North Atlantic; North Atlantic oscillation
• Online Access: https://hdl.handle.net/20.500.12468/834; https://doi.org/10.1007/s00382-017-3782-y

The timing of climate responses to the Bond cycle is investigated in the western Mediterranean. Periodicities had been previously reported in a marine sediment record from this region spanning the last 20 kyr, and registered by diverse paleoenvironmental proxies, in particular those associated with terrigenous input, redox conditions, productivity, sea surface temperature (SST) and salinity. Further cross-spectral analyses on these time series reveal leads–lags in the 1400 year climate cycle. Considering as reference a terrigenous input proxy (the K/Al ratio), all the paleoenvironmental proxies displayed time shifts varying from ca. 700 year to ca. 350 year. SST and salinity variations show a first leaded response with the inflow of cold and less salty Atlantic waters. Followed by a time lead of 525 year, progresively arid conditions with an increase of eolian dust transport to the area, given by the Zr/Al signal, are observed. The intensification of dust transport could have triggered a latest biological response, lead by 350 year, with an increase of productivity, as suggested by the Ba/Al ratio. Lastly changes in the Mediterranean thermohaline circulation, indicated by a selected redox proxy (the U/Th ratio), are observed. These results support that the oceanic response triggered the atmospheric response to the Bond cycle in the western Mediterranean. Changes in the North Atlantic Oscillation mode and in the Inter-Tropical Convergence Zone migrations with variations in the monsoon activity or Saharan winds system, are considered as main forcing mechanisms, with a complex relationship of the involved phenomena. Instituto Andaluz de Ciencias de la Tierra, Consejo Superior de Investigaciones Científicas, España Instituto Andaluz de Ciencias de la Tierra, Universidad de Granada, España Departamento de Mineralogía y Petrología, Universidad de Granada, España Departamento de Estratigrafía y Paleontología, Universidad de Granada, España Instituto Geológico y Minero de España, España Ministerio de ...