Tropical climate and vegetation changes during Heinrich event 1; a model-data comparison

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doi: 10.5194/cp-8-37-2012
Author(s): Handiani, Dian; Paul, André; Dupont, L.
Author Affiliation(s): Primary:
University of Bremen, Center for Marine Environmental Sciences (MARUM), Bremen, Germany
Volume Title: Climate of the Past
Source: Climate of the Past, 8(1), p.37-57. Publisher: Copernicus, Katlenburg-Lindau, International. ISSN: 1814-9324
Note: In English. Published in Climate of the Past Discussion: 21 June 2011,; accessed in April 2012. 77 refs.; illus., incl. 4 tables, sketch maps
Summary: Abrupt climate changes from 18 to 15 thousand years before present (kyr BP) associated with Heinrich Event 1 (HE1) had a strong impact on vegetation patterns not only at high latitudes of the Northern Hemisphere, but also in the tropical regions around the Atlantic Ocean. To gain a better understanding of the linkage between high and low latitudes, we used the University of Victoria (UVic) Earth System-Climate Model (ESCM) with dynamical vegetation and land surface components to simulate four scenarios of climate-vegetation interaction: the pre-industrial era, the Last Glacial Maximum (LGM), and a Heinrich-like event with two different climate backgrounds (interglacial and glacial). We calculated mega-biomes from the plant-functional types (PFTs) generated by the model to allow for a direct comparison between model results and palynological vegetation reconstructions. Our calculated mega-biomes for the pre-industrial period and the LGM corresponded well with biome reconstructions of the modern and LGM time slices, respectively, except that our pre-industrial simulation predicted the dominance of grassland in southern Europe and our LGM simulation resulted in more forest cover in tropical and sub-tropical South America. The HE1-like simulation with a glacial climate background produced sea-surface temperature patterns and enhanced inter-hemispheric thermal gradients in accordance with the "bipolar seesaw" hypothesis. We found that the cooling of the Northern Hemisphere caused a southward shift of those PFTs that are indicative of an increased desertification and a retreat of broadleaf forests in West Africa and northern South America. The mega-biomes from our HE1 simulation agreed well with paleovegetation data from tropical Africa and northern South America. Thus, according to our model-data comparison, the reconstructed vegetation changes for the tropical regions around the Atlantic Ocean were physically consistent with the remote effects of a Heinrich event under a glacial climate background.
Year of Publication: 2012
Research Program: ODP Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; Africa; Angola Basin; Atlantic Ocean; Atlantic meridional overturning circulation; Atmospheric precipitation; Biomes; Bogota Colombia; Bolivia; Boreal environment; Brazil; Burundi; Cameroon; Carbon dioxide; Cenozoic; Central Africa; Climate change; Colombia; Colonia Brazil; Cooling; Desertification; Deserts; Earth System-Climate Model; East Africa; East African Lakes; Evaporation; Forests; Fuquene Colombia; General circulation models; Glacial environment; Global change; Global warming; Grasslands; Heinrich events; Holocene; Interglacial environment; La Laguna Bogota Bolivia; Lake Caco; Lake Malawi; Lake Masoko; Lake Tanganyika; Last glacial maximum; Latitude; Leg 175; Microfossils; Miospores; North America; North Atlantic Deep Water; ODP Site 1078; Ocean Drilling Program; Paleoclimatology; Paleoenvironment; Palynomorphs; Quaternary; Saint Lawrence River; Savannas; Sea-surface temperature; Siberia Bolivia; South America; South Atlantic; Tanzania; Terrestrial environment; Three-dimensional models; Trees; Tropical environment; Tundra; Vegetation; West Africa
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Record ID: 2013010059
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Copernicus Gesellschaft, Katlenburg-Lindau, Germany