Ultra-high resolution pollen record from the northern Andes reveals rapid shifts in montane climates within the last two glacial cycles

• Published in: Climate of the Past
• Main Authors: Groot, M. H. M., Bogotá, R. G., Lourens, L. J., Hooghiemstra, H., Vriend, M., Berrio, J. C., Tuenter, E., Plicht, J., Geel, B., Ziegler, M., Weber, S. L., Betancourt, A., Contreras, L., Gaviria, S., Giraldo, C., González, N., Jansen, J. H. F., Konert, M., Ortega, D., Rangel, O., Sarmiento, G., Vandenberghe, J., Hammen, T., Linden, M., Westerhoff, W.
• Format: Text
• Language: English
• Published: 2018
• Subjects: North Atlantic
• Online Access: https://doi.org/10.5194/cp-7-299-2011; https://cp.copernicus.org/articles/7/299/2011/

Here we developed a composite pollen-based record of altitudinal vegetation changes from Lake Fúquene (5° N) in Colombia at 2540 m elevation. We quantitatively calibrated Arboreal Pollen percentages (AP%) into mean annual temperature (MAT) changes with an unprecedented ~60-year resolution over the past 284 000 years. An age model for the AP% record was constructed using frequency analysis in the depth domain and tuning of the distinct obliquity-related variations to the latest marine oxygen isotope stacked record. The reconstructed MAT record largely concurs with the ~100 and 41-kyr (obliquity) paced glacial cycles and is superimposed by extreme changes of up to 7 to 10° Celsius within a few hundred years at the major glacial terminations and during marine isotope stage 3, suggesting an unprecedented North Atlantic – equatorial link. Using intermediate complexity transient climate modelling experiments, we demonstrate that ice volume and greenhouse gasses are the major forcing agents causing the orbital-related MAT changes, while direct precession-induced insolation changes had no significant impact on the high mountain vegetation during the last two glacial cycles.