Seasonal and interannual variability of the mineral dust cycle under present and glacial climate conditions

• Published in: Journal of Geophysical Research
• Main Authors: Werner, M, Tegen, I., Harrison, S, P, Kohfeld, K, E, Prentice, I, C, Balkanski, Yves, Rodhe, H., Roelandt, C.
• Other Authors: Max Planck Institute for Biogeochemistry (MPI-BGC), Max-Planck-Gesellschaft, Leibniz Institute for Tropospheric Research (TROPOS), Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Modelling the Earth Response to Multiple Anthropogenic Interactions and Dynamics (MERMAID), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Department of Meteorology Stockholm (MISU), Stockholm University
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2002
• Subjects: glacial climate; GCM simulation; LGM; GRIP/GISP ice cores; mineral aerosol; dust; [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]; [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology; GISP; Greenland; Greenland ice core; GRIP; ice core
• Online Access: https://hal.science/hal-02870603; https://hal.science/hal-02870603/document; https://hal.science/hal-02870603/file/Werner2002_JGR.pdf; https://doi.org/10.1029/2002JD002365

International audience [1] We present simulations of the dust cycle during present and glacial climate states, using a model, which explicitly simulates the control of dust emissions as a function of seasonal and interannual changes in vegetation cover. The model produces lower absolute amounts of dust emissions and deposition than previous simulations of the Last Glacial Maximum (LGM) dust cycle. However, the simulated 2-to 3-fold increase in emissions and deposition at the LGM compared to today, is in agreement with marine-and ice-core observations, and consistent with previous simulations. The mean changes are accompanied by a prolongation of the length of the season of dust emissions in most source regions. The increase is most pronounced in Asia, where LGM dust emissions are high throughout the winter, spring and summer rather than occurring primarily in spring as they do today. Changes in the seasonality of dust emissions, and hence atmospheric loading, interact with changes in the seasonality of precipitation, and hence of the relative importance of wet and dry deposition processes at high northern latitudes. As a result, simulated dust deposition rates in the high northern latitudes show high interannual variability. Our results suggest that the high dust concentration variability shown by the Greenland ice core records during the LGM is a consequence of changes in atmospheric circulation and precipitation locally rather than a result of changes in the variability of dust emissions. interannual variability of the mineral dust cycle under present and glacial climate conditions