Articles | Volume 16, issue 1
https://doi.org/10.5194/cp-16-117-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/cp-16-117-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
15 Jan 2020
Research article |
| 15 Jan 2020
| 15 Jan 2020
The end of the African humid period as seen by a transient comprehensive Earth system model simulation of the last 8000 years
Anne Dallmeyer
CORRESPONDING AUTHOR
The Land in the Earth System, Max Planck Institute for Meteorology, Bundesstrasse 53, 20146 Hamburg, Germany
Martin Claussen
The Land in the Earth System, Max Planck Institute for Meteorology, Bundesstrasse 53, 20146 Hamburg, Germany
Meteorological Institute, Centrum für Erdsystemforschung und
Nachhaltigkeit (CEN), Universität Hamburg, Bundesstrasse 55, 20146 Hamburg, Germany
Stephan J. Lorenz
The Ocean in the Earth System, Max Planck Institute for Meteorology, Bundesstrasse 53, 20146 Hamburg, Germany
Timothy Shanahan
The University of Texas at Austin, Department of Geological Sciences, 1 University Station C9000, Austin, Texas 78712, USA
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Anne Dallmeyer, Martin Claussen, Stephan J. Lorenz, Michael Sigl, Matthew Toohey, and Ulrike Herzschuh
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Climate model simulations covering the last millennium provide context for the evolution of the modern climate and for the expected changes during the coming centuries. They can help identify plausible mechanisms underlying palaeoclimatic reconstructions. Here, we describe the forcing boundary conditions and the experimental protocol for simulations covering the pre-industrial millennium. We describe the PMIP4 past1000 simulations as contributions to CMIP6 and additional sensitivity experiments.
Anne Dallmeyer, Martin Claussen, Jian Ni, Xianyong Cao, Yongbo Wang, Nils Fischer, Madlene Pfeiffer, Liya Jin, Vyacheslav Khon, Sebastian Wagner, Kerstin Haberkorn, and Ulrike Herzschuh
Clim. Past, 13, 107–134, https://doi.org/10.5194/cp-13-107-2017, https://doi.org/10.5194/cp-13-107-2017, 2017
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Alexander Lemburg, Martin Claussen, and Felix Ament
Clim. Past Discuss., https://doi.org/10.5194/cp-2016-68, https://doi.org/10.5194/cp-2016-68, 2016
Manuscript not accepted for further review
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Ulrike Port, Martin Claussen, and Victor Brovkin
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Sabine Egerer, Martin Claussen, Christian Reick, and Tanja Stanelle
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U. Port and M. Claussen
Clim. Past, 11, 1563–1574, https://doi.org/10.5194/cp-11-1563-2015, https://doi.org/10.5194/cp-11-1563-2015, 2015
V. P. Groner, M. Claussen, and C. Reick
Clim. Past, 11, 1361–1374, https://doi.org/10.5194/cp-11-1361-2015, https://doi.org/10.5194/cp-11-1361-2015, 2015
U. Port, M. Claussen, and V. Brovkin
Clim. Past Discuss., https://doi.org/10.5194/cpd-11-997-2015, https://doi.org/10.5194/cpd-11-997-2015, 2015
Revised manuscript not accepted
A. Dallmeyer, M. Claussen, N. Fischer, K. Haberkorn, S. Wagner, M. Pfeiffer, L. Jin, V. Khon, Y. Wang, and U. Herzschuh
Clim. Past, 11, 305–326, https://doi.org/10.5194/cp-11-305-2015, https://doi.org/10.5194/cp-11-305-2015, 2015
K. Lohmann, J. H. Jungclaus, D. Matei, J. Mignot, M. Menary, H. R. Langehaug, J. Ba, Y. Gao, O. H. Otterå, W. Park, and S. Lorenz
Ocean Sci., 10, 227–241, https://doi.org/10.5194/os-10-227-2014, https://doi.org/10.5194/os-10-227-2014, 2014
F. S. E. Vamborg, V. Brovkin, and M. Claussen
Earth Syst. Dynam., 5, 89–101, https://doi.org/10.5194/esd-5-89-2014, https://doi.org/10.5194/esd-5-89-2014, 2014
M. Claussen, K. Selent, V. Brovkin, T. Raddatz, and V. Gayler
Biogeosciences, 10, 3593–3604, https://doi.org/10.5194/bg-10-3593-2013, https://doi.org/10.5194/bg-10-3593-2013, 2013
J. Segschneider, A. Beitsch, C. Timmreck, V. Brovkin, T. Ilyina, J. Jungclaus, S. J. Lorenz, K. D. Six, and D. Zanchettin
Biogeosciences, 10, 669–687, https://doi.org/10.5194/bg-10-669-2013, https://doi.org/10.5194/bg-10-669-2013, 2013
Related subject area
Subject: Vegetation Dynamics | Archive: Modelling only | Timescale: Holocene
The challenge of comparing pollen-based quantitative vegetation reconstructions with outputs from vegetation models – a European perspective
How does the explicit treatment of convection alter the precipitation–soil hydrology interaction in the mid-Holocene African humid period?
Effect of nitrogen limitation and soil biophysics on Holocene greening of the Sahara
Holocene vegetation transitions and their climatic drivers in MPI-ESM1.2
Harmonising plant functional type distributions for evaluating Earth system models
Controls on fire activity over the Holocene
North African vegetation–precipitation feedback in early and mid-Holocene climate simulations with CCSM3-DGVM
Comparing modelled fire dynamics with charcoal records for the Holocene
Climate and CO2 modulate the C3/C4 balance and δ13C signal in simulated vegetation
Anne Dallmeyer, Anneli Poska, Laurent Marquer, Andrea Seim, and Marie-José Gaillard
Clim. Past, 19, 1531–1557, https://doi.org/10.5194/cp-19-1531-2023, https://doi.org/10.5194/cp-19-1531-2023, 2023
Short summary
Short summary
We compare past tree cover changes in Europe during the last 8000 years simulated with two dynamic global vegetation models and inferred from pollen data. The major model–data mismatch is related to the much earlier onset of anthropogenic deforestation in the data compared to the prescribed land use in the models. We show that land use, and not climate, is the main driver of the Holocene forest decline. The model–data agreement depends on the model tuning, challenging model–data comparisons.
Leonore Jungandreas, Cathy Hohenegger, and Martin Claussen
Clim. Past, 19, 637–664, https://doi.org/10.5194/cp-19-637-2023, https://doi.org/10.5194/cp-19-637-2023, 2023
Short summary
Short summary
Increasing the vegetation cover over mid-Holcocene North Africa expands the West African monsoon ∼ 4–5° further north. This northward shift of monsoonal precipitation is caused by interactions of the land surface with large-scale monsoon circulation and the coupling of soil moisture to precipitation. We highlight the importance of considering not only how soil moisture influences precipitation but also how different precipitation characteristics alter the soil hydrology via runoff generation.
Jooyeop Lee, Martin Claussen, Jeongwon Kim, Je-Woo Hong, In-Sun Song, and Jinkyu Hong
Clim. Past, 18, 313–326, https://doi.org/10.5194/cp-18-313-2022, https://doi.org/10.5194/cp-18-313-2022, 2022
Short summary
Short summary
It is still a challenge to simulate the so–called Green Sahara (GS), which was a wet and vegetative Sahara region in the mid–Holocene, using current climate models. Our analysis shows that Holocene greening is simulated better if the amount of soil nitrogen and soil texture is properly modified for the humid and vegetative GS period. Future climate simulation needs to consider consequent changes in soil nitrogen and texture with changes in vegetation cover for proper climate simulations.
Anne Dallmeyer, Martin Claussen, Stephan J. Lorenz, Michael Sigl, Matthew Toohey, and Ulrike Herzschuh
Clim. Past, 17, 2481–2513, https://doi.org/10.5194/cp-17-2481-2021, https://doi.org/10.5194/cp-17-2481-2021, 2021
Short summary
Short summary
Using the comprehensive Earth system model, MPI-ESM1.2, we explore the global Holocene vegetation changes and interpret them in terms of the Holocene climate change. The model results reveal that most of the Holocene vegetation transitions seen outside the high northern latitudes can be attributed to modifications in the intensity of the global summer monsoons.
Anne Dallmeyer, Martin Claussen, and Victor Brovkin
Clim. Past, 15, 335–366, https://doi.org/10.5194/cp-15-335-2019, https://doi.org/10.5194/cp-15-335-2019, 2019
Short summary
Short summary
A simple but powerful method for the biomisation of plant functional type distributions is introduced and tested for six different dynamic global vegetation models based on pre-industrial and palaeo-simulations. The method facilitates the direct comparison between vegetation distributions simulated by different Earth system models and between model results and the pollen-based biome reconstructions. It is therefore a powerful tool for the evaluation of Earth system models.
S. Kloster, T. Brücher, V. Brovkin, and S. Wilkenskjeld
Clim. Past, 11, 781–788, https://doi.org/10.5194/cp-11-781-2015, https://doi.org/10.5194/cp-11-781-2015, 2015
R. Rachmayani, M. Prange, and M. Schulz
Clim. Past, 11, 175–185, https://doi.org/10.5194/cp-11-175-2015, https://doi.org/10.5194/cp-11-175-2015, 2015
Short summary
Short summary
The role of vegetation-precipitation feedbacks in modifying the North African rainfall response to enhanced early to mid-Holocene summer insolation is analysed using the climate-vegetation model CCSM3-DGVM. Dynamic vegetation amplifies the positive early to mid-Holocene summer precipitation anomaly by ca. 20% in the Sahara-Sahel region. The primary vegetation feedback operates through surface latent heat flux anomalies by canopy evapotranspiration and their effect on the African easterly jet.
T. Brücher, V. Brovkin, S. Kloster, J. R. Marlon, and M. J. Power
Clim. Past, 10, 811–824, https://doi.org/10.5194/cp-10-811-2014, https://doi.org/10.5194/cp-10-811-2014, 2014
O. Flores, E. S. Gritti, and D. Jolly
Clim. Past, 5, 431–440, https://doi.org/10.5194/cp-5-431-2009, https://doi.org/10.5194/cp-5-431-2009, 2009
Cited articles
Adkins, J., deMenocal, P., and Eshel, G.: The “African Humid Period” and the record of marine upwelling from excess 230Th in ODP Hole 658C,
Paleoceanography, 21, PA4203, https://doi.org/10.1029/2005PA001200, 2006.
Bader, J., Jungclaus, J., Krivova, N., Lorenz, S., Maycock, A., Raddatz, T.,
Schmidt, H., Toohey, M., Wu, C.-J., and Claussen, M.: Global temperature
modes shed light on the Holocene temperature conundrum, Nat. Commun., submitted, 2019.
Bartlein, P. J. and Shafer, S. L.: Paleo calendar-effect adjustments in time-slice and transient climate-model simulations (PaleoCalAdjust v1.0): impact and strategies for data analysis, Geosci. Model Dev., 12, 3889–3913, https://doi.org/10.5194/gmd-12-3889-2019, 2019.
Bartlein, P. J., Harrison, S. P., Brewer, S., Connor, S., Davis, B. S. A.,
Gajewski, K., Guiot, J., Harrison-Prentice, T. I., Henderson, A., Peyron, O.,
Prentice, J. C., Scholze, M., Seppä, H., Shuman, B., Sugita, S.,
Thompson, R. S., Viau, A. E., Williams, J., and Wu, H.: Pollen-based
continental climate reconstructions at 6 and 21 ka: A global synthesis,
Clim. Dynam., 37, 775–802, https://doi.org/10.1007/s00382-010-0904-1, 2011.
Berger, A. L.: Long term variations of daily insolation and quaternary climatic changes, J. Atmos. Sci., 5, 2362–2367, 1978.
Bosmans, J. H. C., Drijfhout, S. S., Tuenter, E., Lourens, L. J., Hilgen, F. J., and Weber, S. L.: Monsoonal response to mid-holocene orbital forcing in a high resolution GCM, Clim. Past, 8, 723–740, https://doi.org/10.5194/cp-8-723-2012, 2012.
Bosmans, J., Drijfhout, S., Tuenter, E., Hilgen, F., and Lourens, L.:
Response of the North African summer monsoon to precession and obliquity
forcings in the EC-Earth GCM, Clim. Dynam., 44, 279–297,
https://doi.org/10.1007/s00382-014-2260-z, 2014.
Braconnot, P., de Noblet, N., and Ramstein, G.: Mid-Holocene and last glacial maximum African monsoon changes as simulated within the Paleoclimate
Modelling Intercomparison Project, Global Planet. Change, 26, 51–66, 2000.
Braconnot, P., Otto-Bliesner, B., Harrison, S., Joussaume, S., Peterchmitt, J.-Y., Abe-Ouchi, A., Crucifix, M., Driesschaert, E., Fichefet, Th., Hewitt, C. D., Kageyama, M., Kitoh, A., Loutre, M.-F., Marti, O., Merkel, U., Ramstein, G., Valdes, P., Weber, L., Yu, Y., and Zhao, Y.: Results of PMIP2 coupled simulations of the Mid-Holocene and Last Glacial Maximum – Part 2: feedbacks with emphasis on the location of the ITCZ and mid- and high latitudes heat budget, Clim. Past, 3, 279–296, https://doi.org/10.5194/cp-3-279-2007, 2007.
Braconnot, P., Marzin, C., Grégoire, L., Mosquet, E., and Marti, O.: Monsoon response to changes in Earth's orbital parameters: comparisons between simulations of the Eemian and of the Holocene, Clim. Past, 4, 281–294, https://doi.org/10.5194/cp-4-281-2008, 2008.
Braconnot, P., Harrison, S., Bartlein, P., Masson-Delmotte, V., Abe-Ouchi,
A., Otto-Bliesner, B., and Zhao, Y.: Evaluation of climate models using
palaeoclimatic data, Nat. Clim. Change, 2, 417–424,
https://doi.org/10.1038/nclimate1456, 2012.
Braconnot, P., Zhu, D., Marti, O., and Servonnat, J.: Strengths and challenges for transient Mid- to Late Holocene simulations with dynamical vegetation, Clim. Past, 15, 997–1024, https://doi.org/10.5194/cp-15-997-2019, 2019.
Brovkin, V., Raddatz, T., Reick, C. H., Claussen, M., and Gayler, V.: Global biogeophysical interactions between forest and climate, Geophys. Res. Lett., 36, L07405, https://doi.org/10.1029/2009GL037543, 2009.
Brovkin, V., Lorenz, S., Raddatz, T., Ilyina, T., Stemmler, I., Toohey, M., and Claussen, M.: What was the source of the atmospheric CO2 increase during the Holocene?, Biogeosciences, 16, 2543–2555, https://doi.org/10.5194/bg-16-2543-2019, 2019.
Claussen, M. and Gayler, V.: The Greening of the Sahara during the
Mid-Holocene: Results of an Interactive Atmosphere-Biome Model, Global
Ecol. Biogeogr., 6, 369–377, 1997.
Claussen, M., Kubatzki, C., Brovkin, V., Ganopolski, A., Hoelzmann, P., and
Pachur, H. J: Simulation of an abrupt change in Saharan vegetation in the mid-Holocene, Geophys. Res. Lett., 26, 2037–2040, 1999.
Claussen, M., Dallmeyer, A., and Bader, J.: Theory and modeling of the
African humid period and the green Sahara, Oxford Research Encyclopedia
of Climate Science, https://doi.org/10.1093/acrefore/9780190228620.013.532, 2017.
Cohen, J.: A coefficient of agreement for nominal scales, Educ. Psychol.
Meas., 20, 37–46, 1960.
Collins, J., Prange, M., Caley, T., and Schefuß, E.: Rapid termination
of the African Humid Period triggered by northern high-latitude cooling,
Nat. Commun., 8, 1372, https://doi.org/10.1038/s41467-017-01454-y, 2017.
COHMAP Members: Climatic changes of the last 18,000 years: Observations and
model simulations, Science, 241, 1043–1052, 1988.
Cook, K. H.: Generation of the African easterly jet and its role in
determining west African precipitation, J. Climate, 12, 1165–1184, 1999.
Dallmeyer, A., Claussen, M., and Brovkin, V.: Harmonising plant functional type distributions for evaluating Earth system models, Clim. Past, 15, 335–366, https://doi.org/10.5194/cp-15-335-2019, 2019.
deMenocal, P. B. and Tierney, J. E.: Green Sahara: African Humid Periods
Paced by Earth's Orbital Changes, Nature Education Knowledge, 3, 12, 1–6, 2012.
deMenocal, P. B., Ortiz, J., Guilderson, T., Adkins, J., Santhein, M., Baker,
L., and Yarusinsky, M.: Abrupt onset and termination of the African Humid
Period: Rapid climate responses to gradual insolation forcing, Quaternary
Sci. Rev., 19, 347–361, 2000.
Dezfuli, A.: Climate of Western and Central Equatorial Africa, Oxford Research Encyclopedia of Climate Science,
https://doi.org/10.1093/acrefore/9780190228620.013.511, 2017.
Egerer, S., Claussen, M., and Reick, C.: Rapid increase in simulated North Atlantic dust deposition due to fast change of northwest African landscape during the Holocene, Clim. Past, 14, 1051–1066, https://doi.org/10.5194/cp-14-1051-2018, 2018.
Foody, G. M.: Status of land cover classification accuracy assessment, Remote
Sens. Environ., 80, 185–201, 2002.
Fröhlich, L., Knippertz, P., Fink, A. H., and Hohberger, E.: An objective
climatology of tropical plumes, J. Climate, 26, 5044–5060, 2013.
Gaetani, M., Messori, G., Zhang, Q., Flamant C., and Pausata, F. S.:
Understanding the Mechanisms behind the Northward Extension of the West
African Monsoon during the Mid-Holocene, J. Climate, 30, 7621–7642,
https://doi.org/10.1175/JCLI-D-16-0299.1, 2017.
Geb, M.: Factors favouring precipitation in North Africa: Seen from the
viewpoint of present-day climatology, Global Planet. Change, 26, 85–96, 2000.
Goll, D. S., Brovkin, V., Liski, J., Raddatz, T., Thum, T., and Todd-Brown,
K. E. O.: Strong dependence of CO2 emissions from anthropogenic land cover change on initial land cover and soil carbon parametrization, Global
Biogeochem. Cy., 29, 1511–1523, https://doi.org/10.1002/2014gb004988, 2015.
Grist, J. P. and Nicholson, S. E.: A study of the dynamic factors
influencing the rainfall variability in the west african sahel, J. Climate, 14, 1337–1359, 2001.
Hagemann, S. and Stacke, T.: Impact of the soil hydrology scheme on simulated soil moisture memory, Clim. Dynam., 44, 1731–1750, https://doi.org/10.1007/s00382-014-2221-6, 2015.
Harrison, S.: BIOME 6000 DB classified plotfile version 1, University of
Reading, Dataset, https://doi.org/10.17864/1947.99, 2017.
Harrison, S. P., Bartlein, P. J., Brewer, S., Prentice, I. C., Boyd, M.,
Hessler, I., Holmgren, K., Izumi, K., and Willis, K.: Climate model benchmarking with glacial and mid-Holocene climates, Clim. Dynam., 43, 671–688, https://doi.org/10.1007/s00382-013-1922-6, 2014.
Hély, C., Lézine, A.-M., and contributors, A.: Holocene changes in African vegetation: tradeoff between climate and water availability, Clim. Past, 10, 681–686, https://doi.org/10.5194/cp-10-681-2014, 2014.
Hoelzmann, P., Jolly, D., Harrison, S. P., Laarif, F., Bonnefille, R., and
Pachur, H.-J.: Mid-Holocene land-surface conditions in northern Africa and
the Arabian Peninsula: A data set for the analysis of biogeophysical
feedbacks in the climate system, Global Biogeochem. Cy., 12, 35–51,
1998.
Hoelzmann, P., Kruse, H.-J., and Rottinger, F.: Precipitation estimates for
the eastern Saharan palaeomonsoon based on a water balance model of the West
Nubian Palaeolake Basin, Global Planet. Change, 26, 105–120, 2000.
Hoelzmann, P., Keding, B., Berke, H., Kröpelin, S., and Kruse, H. J.:
Environmental change and archaeology: lake evolution and human occupation in
the Eastern Sahara during the Holocene, Palaeogeogr. Palaeocl., 169, 193–217, 2002.
Hurtt, G. C., Chini, L. P., Frolking, S., Betts, R. A., Feddema, J.,
Fischer, G., Fisk, J. P., Hibbard, K., Houghton, R. A., Janetos, A., Jones,
C. D., Kindermann, G., Kinoshita, T., Goldewijk, K. K., Riahi, K.,
Shevliakova, E., Smith, S., Stehfest, E., Thomson, A., Thornton, P., van
Vuuren, D. P., and Wang, Y. P.: Harmonization of land-use scenarios for the
period 1500–2100: 600 years of global gridded annual land-use transitions,
wood harvest, and resulting secondary lands, Climatic Change, 109, 117–161,
https://doi.org/10.1007/s10584-011-0153-2, 2011.
Ilyina, T., Six, K., Segschneider, J., Maier-Reimer, E., Li, H., and
Núñez-Riboni, I.: Global ocean biogeochemistry model HAMOCC: Model
architecture and performance as component of the MPI-Earth System Model in
different CMIP5 experimental realizations, J. Adv. Model. Earth Sy., 5, 287–315, https://doi.org/10.1029/2012MS000178, 2013.
Janiga, M. A. and Thorncroft, C. D.: The Infuence of African Easterly Waves on Convection over Tropical Africa and the East Atlantic, Mon. Weather Rev., 144, 171–192, 2016.
Jolly, D., Prentice, I. C., Bonneille, R., Ballouche, A., Bengo, M., Brenac, P., Buchet, G., Burney, D., Cazet, J.-P., Cheddadi, R., Edorh, T., Elenga, H., Elmoutaki, S., Guiot, J., Laarif, F., Lamb, H., Lezine, A.-M., Maley, J., Mbenza, M., Peyron, O., Reille, M., Reynaud-Farrera, I., Riollet, G., Ritchie, J. C., Roche, E., Scott, L., Ssemmanda, I., Straka, H., Umer, M., Van Campo, E., Vilimumbalo, S., Vincens, A., and Waller, M.: Biome reconstruction from pollen and plant macrofossil data for Africa and the Arabian peninsula at 0 and 6000 years, J. Biogeogr., 25, 1007–1027, 1998.
Joussaume, S., Taylor, K. E., Braconnot, P., Mitchell, J. F. B., Kutzbach,
J. E., Harrison, S. P., Prentice, I. C., Broccoli, A. J., Abe-Ouchi, A.,
Bartlein, P. J., Bonfiels, C., Dong., B., Guiot, J., Herterich, K., Hewit,
C. D., Jolly, D., Kim, J. W., Kislov, A., Kitoh, A., Loutre, M. F., Masson, V., McAvaney, B., McFarlane, N., deNoblet, N., Peltier, W. R., Peterschmitt, J. Y., Pollard, D., Rind, D., Royer, J. F., Schlesinger, M. E., Syktus, J., Thompson, S., Valdes, P., Vettoretti, G., Webb, R. S., and Wyputta, U.: Monsoon changes for 6000 years ago: Results of 18 simulations from the Paleoclimate Modeling Intercomparison Project (PMIP), Geophys. Res. Lett., 26, 859–862, 1999.
Jungclaus, J. H., Fischer, N., Haak, H., Lohmann, K., Marotzke, J., Matei,
D., Mikolajewicz, U., Notz, D., and von Storch, J. S.: Characteristics of
the ocean simulations in the Max Planck Institute Ocean Model (MPIOM) the
ocean component of the MPI-Earth system model, J. Adv. Model. Earth Sy., 5, 422–446, https://doi.org/10.1002/jame.20023, 2013.
Knippertz, P.: Tropical–extratropical interactions causing precipitation in Northwest Africa: Statistical analysis and seasonal variations, Mon. Weather Rev., 131, 3069–3076, 2003.
Knippertz, P.: Tropical–extratropical interactions related to upper-level
troughs at low latitudes, Dynam. Atmos. Oceans, 43, 36–62, 2007.
Knippertz, P. and Martin, J. E.: Tropical plumes and extreme precipitation in subtropical and tropical West Africa, Q. J. Roy. Meteor. Soc., 131, 2337–2365, https://doi.org/10.1256/qj.04.148, 2005.
Knippertz, P., Fink, A. H., Reiner, A., and Speth, P.: Three late
summer/early autumn cases of tropical–extratropical interactions causing
precipitation in Northwest Africa, Mon. Weather Rev., 131, 116–135, 2003.
Köhler, P.: Interactive comment on “What was the source of the atmospheric CO2 increase during the Holocene?” by Victor Brovkin et al., Biogeosciences Discuss., C1–C6, https://doi.org/10.5194/bg-2019-64-SC1, 2019.
Krinner, G., Lezine, A. M., Braconnot, P., Sepulchre, P., Ramstein, G.,
Grenier, C., and Gouttevin, I.: A reassessment of lake and wetland feedbacks on the North African Holocene climate, Geophys. Res. Lett., 39, L07701, https://doi.org/10.1029/2012GL050992, 2012.
Krivova, N. A., Solanki, S. K., and Unruh, Y. C.: Towards a long-term record of solar total and spectral irradiance, J. Atmos. Sol.-Terr. Phy., 73, 223–234, https://doi.org/10.1016/j.jastp.2009.11.013, 2011.
Kröpelin, S., Verschuren, D., Lézine, A. M., Eggermont, H., Cocquyt, C., Francus, P., Cazet, J. P., Fagot, M., Rumes, B., Russell, J. M., Darius, F., Conley, D. J., Schuster, M., von Suchodoletz, H., and Engstrom, D. R.: Climate-driven ecosystem succession in the Sahara: The past 6000 years, Science, 320, 765–768, 2008.
Kuper, R. and Kröpelin, S.: Climate-controlled Holocene occupation of the Sahara: Motor of Africa's evolution, Science, 313, 803–807, 2006.
Kutzbach, J. E.: Monsoon climate of the early Holocene: Climate experiment with the Earth's orbital parameters for 9000 years ago, Science, 214, 59–61, 1981.
Kutzbach, J. E. and Liu, Z.: Response of the African Monsoon to Orbital
Forcing and Ocean Feedbacks in the Middle Holocene, Science, 278, 440–443, 1997.
Kutzbach, J. E., Chen, G., Cheng, H., Edwards, L. R., and Liu, Z.: Potential role of winter rainfall in explaining increased moisture in theMediterranean and Middle East during periods of maximum orbitally-forced insolation seasonality, Clim. Dynam., 42, 1079–1095, 2014.
Lemburg, A., Bader, J., and Claussen, M.: Sahel rainfall – Tropical
Easterly Jet relationship on synoptic to intraseasonal time scales, Mon. Weather Rev., 147, 1733–1752, https://doi.org/10.1175/MWR-D-18-0254.1, 2019.
Levis, S., Bonan, G., and Bonfils, C.: Soil feedback drives the
mid-Holocene North African monsoon northward in fully coupled CCSM2
simulations with a dynamic vegetation model, Clim. Dynam., 23, 791–802, 2004.
Lézine, A.-M., Hély, C., Grenier, C., Braconnot, P., and Krinner, G.: Sahara and Sahel vulnerability to climate changes, lessons from Holocene hydrological data, Quaternary Sci. Rev., 30, 3001–3012, 2011.
Liu, Z., Wang, Y., Gallimore, R., Notaro, M., and Prentice, I. C.: On the cause of abrupt vegetation collapse in North Africa during the Holocene: Climate variability vs. vegetation feedback, Geophys. Res. Lett., 33, L22709, https://doi.org/10.1029/2006GL028062, 2006.
Liu, Z., Wang, Y., Gallimore, R., Gasse, F., Johnson, T., deMenocal, P., Adkins, J., Notaro, M., Prentice, I. C., Kutzbach, J., Jacob, R., Behling, P., Wang, L., and Ong, E.: Simulating the transient evolution and abrupt change of Northern Africa
atmosphere-ocean-terrestrial ecosystem in the Holocene, Quaternary Sci. Rev., 26, 1818–1837, 2007.
Mauritsen, T., Bader, J., Becker, T., Behrens, J., Bittner, M., Brokopf, R., Brovkin, V., Claussen, M., Crueger, T., Esch, M., Fast, I., Fiedler, S., Popke, D., Gayler, V., Giorgetta, M., Goll, D., Haak, H., Hagemann, S., Hedemann, C., Hohenegger, C., Ilyina, T., Jahns, T., Jimenez Cuesta de la Otero, D., Jungclaus, J., Kleinen, T., Kloster, S., Kracher, D., Kinne, S., Kleberg, D., Lasslop, G., Kornblueh, L., Marotzke, J., Matei, D., Meraner, K., Mikolajewicz, U., Modali, K., Möbis, B., Müller, W., Nabel, J., Nam, C., Notz, D., Nyawira, S., Paulsen, H., Peters, K., Pincus, R., Pohlmann, H., Pongratz, J., Popp, M., Raddatz, T., Rast, S., Redler, R., Reick, C., Rohrschneider, T., Schemann, V., Schmidt, H., Schnur, R., Schulzweida, U., Six, K., Stein, L., Stemmler, I., Stevens, B., von Storch, J., Tian, F., Voigt, A., de Vrese, P., Wieners, K.-H., Wilkenskjeld, S., Roeckner, E., and Winkler, A.: Developments in the MPI-M Earth System Model version 1.2 (MPI-ESM1.2) and its response to increasing CO2, J. Adv. Model. Earth Sy., 11, 998–1038, https://doi.org/10.1029/2018MS001400, 2019.
McGee, D., deMenocal, P. B., Winckler, G., Stuut, J. B. W., and Bradtmiller, L. I.: The magnitude, timing and abruptness of changes in North African dust deposition over the last 20,000 yr, Earth Planet. Sc. Lett., 371–372, 163–176, 2013.
Meyer, D., Dimitriadou, E., Hornik, K., Weingessel A., and Leisch F.: e1071:
Misc Functions of the Department of Statistics (e1071), TU Wien, R package
version 1.6-4, available at: https://cran.r-project.org/src/contrib/Archive/e1071/ (last access: 14 December 2019), 2014.
MPG.PuRe, Publication Repository of the Max-Planck-Society,
http://hdl.handle.net/21.11116/0000-0003-F299-F, last access: 16 December 2019.
Nicholson, S. E.: On the factors modulating the intensity of the tropical rainbelt over West Africa, Int. J. Climatol., 29, 673–689, 2009.
Nicholson, S. E. and Grist, J. P.: The Seasonal Evolution of the Atmospheric
Circulation over West Africa and Equatorial Africa, J. Climate, 16, 1013–1030, 2003.
Patricola, C. M. and Cook, K. H.: Dynamics of the West African Monsoon under
Mid-Holocene Precessional Forcing: Regional Climate Model Simulations,
J. Climate, 20, 694–716, 2007.
Pausata, F., Messori, G., and Zhang, Q.: Impacts of dust reduction on the
northward expansion of the African monsoon during the Green Sahara period,
Earth Planet. Sc. Lett., 434, 298–307, https://doi.org/10.1016/j.epsl.2015.11.049, 2016.
Perez-Sanz, A., Li, G., González-Sampériz, P., and Harrison, S. P.: Evaluation of modern and mid-Holocene seasonal precipitation of the Mediterranean and northern Africa in the CMIP5 simulations, Clim. Past, 10, 551–568, https://doi.org/10.5194/cp-10-551-2014, 2014.
Peyron, O., Jolly, D., Braconnot, P., Bonnefille, R., Guiot, J., Wirrmann, D., and Chalié, F.: Quantitative reconstructions of annual rainfall in Africa 6000 years ago: Model-data comparison, J. Geophys. Res., 111, D24110, https://doi.org/10.1029/2006JD007396, 2006.
Rachmayani, R., Prange, M., and Schulz, M.: North African vegetation–precipitation feedback in early and mid-Holocene climate simulations with CCSM3-DGVM, Clim. Past, 11, 175–185, https://doi.org/10.5194/cp-11-175-2015, 2015.
R Core Team: R: A language and environment for statistical computing, R Foundation for Statistical Computing, Vienna, Austria, available at:
http://www.R-project.org/ (last access: 14 December 2019), 2014.
Reick, C. H., Raddatz, T., Brovkin, V., and Gayler, V.: The representation
of natural and anthropogenic land cover change in MPI-ESM, J. Adv. Model.
Earth Sy., 5, 1–24, https://doi.org/10.1002/jame.20022, 2013.
Renssen, H., Brovkin, V., Fichefet, T., and Goosse, H.: Holocene climate
instability during the termination of the African Humid Period, Geophys. Res. Lett., 30, 1184, https://doi.org/10.1029/2002GL016636, 2003.
Roehrig, R., Bouniol, D., Guichard, F., Hourdin, F., and Redelsperger,
J.-L.: The present and future of the West African monsoon: A
process-oriented assessment of CMIP5 simulations along the AMMA transect,
J. Climate, 26, 6471–6505, 2013.
Rossignol-Strick, M: Mediterranean Quaternary sapropels, an immediate
response of the Africa monsoon to variation of insolation, Palaeogeogr.
Palaeocl., 49, 237–263, 1985.
Shanahan, T. M., Mckay, N. P., Hughen, K. A., Overpeck, J. T., Otto-Bliesner, B., Heil, C. W., King, J., Scholz, C. A., and Peck, J.: The time-transgressive termination of the African humid period, Nat. Geosci., 8,
140–144, https://doi.org/10.1038/ngeo2329, 2015.
Skinner, C. B. and Diffenbaugh, N. S.: The contribution of African easterly
waves to monsoon precipitation in the CMIP3 ensemble, J. Geophys. Res.-Atmos., 118, 3590–3609, https://doi.org/10.1002/jgrd.50363, 2013.
Skinner C. B. and Poulsen, C. J.: The role of fall season tropical plumes in
enhancing Saharan rainfall during the African Humid Period, Geophys. Res.
Lett., 43, 349–358, https://doi.org/10.1002/2015GL066318, 2016.
Skonieczny, C., McGee, D., Winckler, G., Bory, A., Bradtmiller, L. I.,
Kinsley, C. W., Polissar, P. J., De Pol-Holz, R., Rossignol, L., and
Malaizé, B.: Monsoon-driven Saharan dust variability over the past
240,000 years, Science Advances, 5, eaav1887,
https://doi.org/10.1126/sciadv.aav1887, 2019.
Stevens, B., Giorgetta, M., Esch, M., Mauritsen, T., Crueger, T., Rast, S.,
Salzmann, M., Schmidt, H., Bader, J., Block, K., Brokopf, R., Fast, I.,
Kinne, S., Kornblueh, L., Lohmann, U., Pincus, R., Reichler, T., and
Roeckner, E.: Atmospheric component of the MPI-M Earth System Model: ECHAM6,
J. Adv. Model. Earth Sy., 5, 146–172, https://doi.org/10.1002/jame.20015, 2013.
Street-Perrott, F. A., Marchand, D. S., Roberts, N., and Harrison, S. P.:
Global Lake-Level Variations from 18,000 to 0 Years Ago: A Paleoclimatic Analysis. U.S. Department of Energy Technical Report 46, Washington, D.C. 20545. Distributed by National Technical Information Service, Springfield, VA 22161, 1989.
Su, H. and Neelin, J. D.: Dynamical mechanisms for African monsoon changes
during the mid-Holocene, J. Geophys. Res., 110, D19105, https://doi.org/10.1029/2005JD005806, 2005.
Swann, A. L. S., Fung, I. Y., Liu, Y., and Chiang, J. C. H.: Remote vegetation feedbacks and the mid-Holocene Green Sahara, J. Climate, 27,
4857–4870, 2014.
Tang, G., Shafer, S. L., Bartlein, P., and Holman, J.: Effects of experimental protocol on global vegetation model accuracy: a comparison of simulated and observed vegetation patterns for Asia, Ecol. Model., 220, 1481–1491, 2009.
Thompson, A. J., Skinner, C. B., Poulsen, C. J., and Zhu, J.: Modulation of
mid-Holocene African rainfall by dust aerosol direct and indirect effects,
Geophys. Res. Lett., 46, 3917–3926, https://doi.org/10.1029/2018GL081225, 2019.
Tierney, J. E., Lewis, S. C., Cook, B. I., LeGrande, A. N., and Schmidt, G.
A.: Model, proxy and isotopic perspectives on the East African Humid Period,
Earth Planet. Sc. Lett., 307, 103–112, 2011.
Tierney, J. E., Pausata, F. S. R., and deMenocal, P. B.: Rainfall regimes of
the Green Sahara, Science Advances, 3, e1601503, https://doi.org/10.1126/sciadv.1601503, 2017.
Toohey, M. and Sigl, M.: Volcanic stratospheric sulfur injections and aerosol optical depth from 500 BCE to 1900 CE, Earth Syst. Sci. Data, 9, 809–831, https://doi.org/10.5194/essd-9-809-2017, 2017.
Tuenter, E., Weber, S. L., Hilgen, F. J., and Lourens, L. J.: The response of
the African summer monsoon to remote and local forcing due to precession and
obliquity, Global Planet. Change, 36, 219–235, 2003.
Vamborg, F. S. E., Brovkin, V., and Claussen, M.: The effect of a dynamic background albedo scheme on Sahel/Sahara precipitation during the mid-Holocene, Clim. Past, 7, 117–131, https://doi.org/10.5194/cp-7-117-2011, 2011.
Wang, B. and LinHo: Rainy season of the Asian-Pacific summer monsoon, J.
Climate, 15, 386–398, https://doi.org/10.1175/1520-0442(2002)015<0386:RSOTAP>2.0.CO;2, 2002.
Wu, M.-L. C., Reale, O., Schubert, S. D., Suarez, M. J., and Thorncroft, C. D.: African easterly jet: Barotropic instability, waves, and cyclogenesis, J.
Climate, 25, 1489–1510, https://doi.org/10.1175/2011JCLI4241.1, 2012.
Zhao, Y., Braconnot, P., Marti, O., Harrison, S., Hewitt, C., Kitoh, A.,
Liu, Z., Mikolajewicz, U., Otto-Bliesner, B., and Weber, S.: A multi-model
analysis of the role of the ocean on the African and Indian monsoon during
the mid-Holocene, Clim. Dynam., 25, 777–800, 2005.
Zielinski, G., Mayewski, P., Meeker, L., Whitlow, S., and Twickler, M.: A
110,000-Yr Record of Explosive Volcanism from the GISP2 (Greenland) Ice
Core, Quaternary Res., 45, 109–118, https://doi.org/10.1006/qres.1996.0013, 1996.
Short summary
We analyse the end of the African humid period (AHP) in a transient Holocene simulation performed with the comprehensive Earth system model MPI-ESM1.2. The model reproduces the time-transgressive end of the AHP evident in proxy data and indicates that changes in moisture can be attributed to the retreat of the summer monsoon and to changes in the extratropical troughs. The spatially varying impact of these systems imposes regionally different responses to the Holocene insolation change.
We analyse the end of the African humid period (AHP) in a transient Holocene simulation...
