Articles | Volume 19, issue 10
https://doi.org/10.5194/cp-19-1891-2023
© Author(s) 2023. 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-19-1891-2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
06 Oct 2023
Research article |
| 06 Oct 2023
| 06 Oct 2023
Contribution of lakes in sustaining the Sahara greening during the mid-Holocene
Yuheng Li
CORRESPONDING AUTHOR
Department of Civil Engineering, Graduate School of Engineering,
University of Tokyo, Tokyo, Japan
Kanon Kino
Department of Civil Engineering, Graduate School of Engineering,
University of Tokyo, Tokyo, Japan
Alexandre Cauquoin
Institute of Industrial Science, University of Tokyo, Kashiwa, Japan
Taikan Oki
Department of Civil Engineering, Graduate School of Engineering,
University of Tokyo, Tokyo, Japan
Related authors
No articles found.
Qing He, Naota Hanasaki, Akiko Matsumura, Edwin H. Sutanudjaja, and Taikan Oki
EGUsphere, https://doi.org/10.5194/egusphere-2025-2952, https://doi.org/10.5194/egusphere-2025-2952, 2025
This preprint is open for discussion and under review for Geoscientific Model Development (GMD).
Short summary
Short summary
This work presents a global groundwater modeling framework at 5-arcminute resolution, developed through an offline coupling of the H08 water resource model and MODFLOW6. The model includes a single-layer aquifer and is designed to capture long-term mean groundwater dynamics under varying climate types. The manuscript describes the model structure, input datasets, and evaluation against available observations.
Georgina Falster, Gab Abramowitz, Sanaa Hobeichi, Cath Hughes, Pauline Treble, Nerilie J. Abram, Michael I. Bird, Alexandre Cauquoin, Bronwyn Dixon, Russell Drysdale, Chenhui Jin, Niels Munksgaard, Bernadette Proemse, Jonathan J. Tyler, Martin Werner, and Carol Tadros
EGUsphere, https://doi.org/10.5194/egusphere-2025-2458, https://doi.org/10.5194/egusphere-2025-2458, 2025
This preprint is open for discussion and under review for Hydrology and Earth System Sciences (HESS).
Short summary
Short summary
We used a random forest approach to produce estimates of monthly precipitation stable isotope variability from 1962–2023, at high resolution across the entire Australian continent. Comprehensive skill and sensitivity testing shows that our random forest models skilfully predict precipitation isotope values in places and times that observations are not available. We make all outputs publicly available, facilitating use in fields from ecology and hydrology to archaeology and forensic science.
Titouan Tcheng, Elise Fourré, Christophe Leroy-Dos-Santos, Frédéric Parrenin, Emmanuel Le Meur, Frédéric Prié, Olivier Jossoud, Roxanne Jacob, Bénédicte Minster, Olivier Magand, Cécile Agosta, Niels Dutrievoz, Vincent Favier, Léa Baubant, Coralie Lassalle-Bernard, Mathieu Casado, Martin Werner, Alexandre Cauquoin, Laurent Arnaud, Bruno Jourdain, Ghislain Picard, Marie Bouchet, and Amaëlle Landais
EGUsphere, https://doi.org/10.5194/egusphere-2025-2863, https://doi.org/10.5194/egusphere-2025-2863, 2025
This preprint is open for discussion and under review for The Cryosphere (TC).
Short summary
Short summary
Studying Antarctic ice cores is crucial to assess past climate changes, as they hold historical climate data. This study examines multiple ice cores from three sites in coastal Adélie Land to see if combining cores improves data interpretability. It does at two sites, but at a third, wind-driven snow layer mixing limited benefits. We show that using multiple ice cores from one location can better uncover climate history, especially in areas with less wind disturbance.
Xin Huang, Qing He, Naota Hanasaki, Rolf H. Reichle, and Taikan Oki
EGUsphere, https://doi.org/10.5194/egusphere-2025-2004, https://doi.org/10.5194/egusphere-2025-2004, 2025
Preprint archived
Short summary
Short summary
This study demonstrates a new method using SMAP soil moisture products to identify irrigation effects, tested to be valid in an example region in California's Central Valley and showed great potential for application in arid/ semi-arid regions. The approach offers a simple, straightforward approach to monitoring irrigation signals without additional in-situ data or model tuning, providing a useful tool to extract irrigation water use data in observation-scarce regions.
Louise C. Sime, Rahul Sivankutty, Irene Malmierca-Vallet, Sentia Goursaud Oger, Allegra N. LeGrande, Erin L. McClymont, Agatha de Boer, Alexandre Cauquoin, and Martin Werner
EGUsphere, https://doi.org/10.5194/egusphere-2025-288, https://doi.org/10.5194/egusphere-2025-288, 2025
Short summary
Short summary
We used climate models to study how stable water isotopes in ice cores changed in the Arctic and Antarctica during the warm Last Interglacial (LIG) period. Whilst standard simulations underestimate polar warming, when the effects of ice sheet meltwater from the preceding deglaciation are included, there is a much better match with observations. Findings suggest that previous estimates of LIG Arctic warming were too high. Understanding these past polar changes can help improve future predictions.
Inès Ollivier, Hans Christian Steen-Larsen, Barbara Stenni, Laurent Arnaud, Mathieu Casado, Alexandre Cauquoin, Giuliano Dreossi, Christophe Genthon, Bénédicte Minster, Ghislain Picard, Martin Werner, and Amaëlle Landais
The Cryosphere, 19, 173–200, https://doi.org/10.5194/tc-19-173-2025, https://doi.org/10.5194/tc-19-173-2025, 2025
Short summary
Short summary
The role of post-depositional processes taking place at the ice sheet's surface on the water stable isotope signal measured in polar ice cores is not fully understood. Using field observations and modelling results, we show that the original precipitation isotopic signal at Dome C, East Antarctica, is modified by post-depositional processes and provide the first quantitative estimation of their mean impact on the isotopic signal observed in the snow.
Giuliano Dreossi, Mauro Masiol, Barbara Stenni, Daniele Zannoni, Claudio Scarchilli, Virginia Ciardini, Mathieu Casado, Amaëlle Landais, Martin Werner, Alexandre Cauquoin, Giampietro Casasanta, Massimo Del Guasta, Vittoria Posocco, and Carlo Barbante
The Cryosphere, 18, 3911–3931, https://doi.org/10.5194/tc-18-3911-2024, https://doi.org/10.5194/tc-18-3911-2024, 2024
Short summary
Short summary
Oxygen and hydrogen stable isotopes have been extensively used to reconstruct past temperatures, with precipitation representing the input signal of the isotopic records in ice cores. We present a 10-year record of stable isotopes in daily precipitation at Concordia Station: this is the longest record for inland Antarctica and represents a benchmark for quantifying post-depositional processes and improving the paleoclimate interpretation of ice cores.
Shinichiro Nakamura, Fuko Nakai, Yuichiro Ito, Ginga Okada, and Taikan Oki
Hydrol. Earth Syst. Sci., 28, 2329–2342, https://doi.org/10.5194/hess-28-2329-2024, https://doi.org/10.5194/hess-28-2329-2024, 2024
Short summary
Short summary
The formation of levee systems is an important factor in determining whether a society fights or adapts to floods. This study presents the levee system transformation process over the past century, from the indigenous levee system to modern continuous levees, and its impacts on human–flood coevolution in the Kiso River basin, Japan, and reveals the interactions between levee systems and human–water systems involving different scales and water phenomena.
Amaelle Landais, Cécile Agosta, Françoise Vimeux, Olivier Magand, Cyrielle Solis, Alexandre Cauquoin, Niels Dutrievoz, Camille Risi, Christophe Leroy-Dos Santos, Elise Fourré, Olivier Cattani, Olivier Jossoud, Bénédicte Minster, Frédéric Prié, Mathieu Casado, Aurélien Dommergue, Yann Bertrand, and Martin Werner
Atmos. Chem. Phys., 24, 4611–4634, https://doi.org/10.5194/acp-24-4611-2024, https://doi.org/10.5194/acp-24-4611-2024, 2024
Short summary
Short summary
We have monitored water vapor isotopes since January 2020 on Amsterdam Island in the Indian Ocean. We show 11 periods associated with abrupt negative excursions of water vapor δ18Ο. Six of these events show a decrease in gaseous elemental mercury, suggesting subsidence of air from a higher altitude. Accurately representing the water isotopic signal during these cold fronts is a real challenge for the atmospheric components of Earth system models equipped with water isotopes.
Christophe Leroy-Dos Santos, Elise Fourré, Cécile Agosta, Mathieu Casado, Alexandre Cauquoin, Martin Werner, Benedicte Minster, Frédéric Prié, Olivier Jossoud, Leila Petit, and Amaëlle Landais
The Cryosphere, 17, 5241–5254, https://doi.org/10.5194/tc-17-5241-2023, https://doi.org/10.5194/tc-17-5241-2023, 2023
Short summary
Short summary
In the face of global warming, understanding the changing water cycle and temperatures in polar regions is crucial. These factors directly impact the balance of ice sheets in the Arctic and Antarctic. By studying the composition of water vapor, we gain insights into climate variations. Our 2-year study at Dumont d’Urville station, Adélie Land, offers valuable data to refine models. Additionally, we demonstrate how modeling aids in interpreting signals from ice core samples in the region.
Xiaoxu Shi, Alexandre Cauquoin, Gerrit Lohmann, Lukas Jonkers, Qiang Wang, Hu Yang, Yuchen Sun, and Martin Werner
Geosci. Model Dev., 16, 5153–5178, https://doi.org/10.5194/gmd-16-5153-2023, https://doi.org/10.5194/gmd-16-5153-2023, 2023
Short summary
Short summary
We developed a new climate model with isotopic capabilities and simulated the pre-industrial and mid-Holocene periods. Despite certain regional model biases, the modeled isotope composition is in good agreement with observations and reconstructions. Based on our analyses, the observed isotope–temperature relationship in polar regions may have a summertime bias. Using daily model outputs, we developed a novel isotope-based approach to determine the onset date of the West African summer monsoon.
Alexandre Cauquoin, Ayako Abe-Ouchi, Takashi Obase, Wing-Le Chan, André Paul, and Martin Werner
Clim. Past, 19, 1275–1294, https://doi.org/10.5194/cp-19-1275-2023, https://doi.org/10.5194/cp-19-1275-2023, 2023
Short summary
Short summary
Stable water isotopes are tracers of climate processes occurring in the hydrological cycle. They are widely used to reconstruct the past variations of polar temperature before the instrumental era thanks to their measurements in ice cores. However, the relationship between measured isotopes and temperature has large uncertainties. In our study, we investigate how the sea surface conditions (temperature, sea ice, ocean circulation) impact this relationship for a cold to warm climate change.
Jiajia Wang, Hongxi Pang, Shuangye Wu, Spruce W. Schoenemann, Ryu Uemura, Alexey Ekaykin, Martin Werner, Alexandre Cauquoin, Sentia Goursaud Oger, Summer Rupper, and Shugui Hou
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2022-384, https://doi.org/10.5194/essd-2022-384, 2022
Revised manuscript not accepted
Short summary
Short summary
Stable water isotopic observations in surface snow over Antarctica provide a basis for validating isotopic models and interpreting Antarctic ice core records. This study presents a new compilation of Antarctic surface snow isotopic dataset based on published and unpublished sources. The database has a wide range of potential applications in studying spatial distribution of water isotopes, model validation, and reconstruction and interpretation of Antarctic ice core records.
Naota Hanasaki, Hikari Matsuda, Masashi Fujiwara, Yukiko Hirabayashi, Shinta Seto, Shinjiro Kanae, and Taikan Oki
Hydrol. Earth Syst. Sci., 26, 1953–1975, https://doi.org/10.5194/hess-26-1953-2022, https://doi.org/10.5194/hess-26-1953-2022, 2022
Short summary
Short summary
Global hydrological models (GHMs) are usually applied with a spatial resolution of about 50 km, but this time we applied the H08 model, one of the most advanced GHMs, with a high resolution of 2 km to Kyushu island, Japan. Since the model was not accurate as it was, we incorporated local information and improved the model, which revealed detailed water stress in subregions that were not visible with the previous resolution.
Daisuke Tokuda, Hyungjun Kim, Dai Yamazaki, and Taikan Oki
Geosci. Model Dev., 14, 5669–5693, https://doi.org/10.5194/gmd-14-5669-2021, https://doi.org/10.5194/gmd-14-5669-2021, 2021
Short summary
Short summary
We developed TCHOIR, a hydrologic simulation framework, to solve fluvial- and thermodynamics of the river–lake continuum. This provides an algorithm for upscaling high-resolution topography as well, which enables the representation of those interactions at the global scale. Validation against in situ and satellite observations shows that the coupled mode outperforms river- or lake-only modes. TCHOIR will contribute to elucidating the role of surface hydrology in Earth’s energy and water cycle.
Marcus Breil, Emanuel Christner, Alexandre Cauquoin, Martin Werner, Melanie Karremann, and Gerd Schädler
Clim. Past, 17, 1685–1699, https://doi.org/10.5194/cp-17-1685-2021, https://doi.org/10.5194/cp-17-1685-2021, 2021
Short summary
Short summary
For the first time an isotope-enabled regional climate simulation for Greenland is performed for the mid-Holocene. Simulation results are compared with observed isotope ratios in ice cores. Compared to global climate simulations, a regional downscaling improves the agreement with measured isotope concentrations. Thus, an isotope-enabled regional climate simulation constitutes a useful supplement to reconstruct regional paleo-climate conditions during the mid-Holocene in Greenland.
Cited articles
Adkins, J., deMenocal, P., and Eshel, G.: The “African humid period” and
the record of marine upwelling from excess 230Th in Ocean Drilling Program Hole 658C, Paleoceanography, 21, PA4203, https://doi.org/10.1029/2005PA001200, 2006.
Bartlein, P. J., Harrison, S. P., Brewer, S., Connor, S., Davis, B. A. S., Gajewski, K., Guiot, J., Harrison-Prentice, T. I., Henderson, A., Peyron, O., and Prentice, I. C.: 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, 2010.
Bercos-Hickey, E., Nathan, T. R., and Chen, S.-H.: On the relationship between the African Easterly Jet, Saharan Mineral Dust Aerosols, and West
African Precipitation, J. Climate, 33, 3533–3546, https://doi.org/10.1175/jcli-d-18-0661.1, 2020.
Berger, A.: Milankovitch theory and climate, Rev. Geophys., 26, 624–657,
https://doi.org/10.1029/RG026i004p00624, 1988.
Biasutti, M. and Sobel, A. H.: Delayed Sahel rainfall and global seasonal
cycle in a warmer climate, Geophys. Res. Lett., 36, L23707,
https://doi.org/10.1029/2009gl041303, 2009.
Braconnot, P., Joussaume, S., Marti, O., and De Noblet, N.: Synergistic
feedbacks from ocean and vegetation on the African monsoon response to
mid-Holocene insolation, Geophys. Res. Lett., 26, 2481–2484,
https://doi.org/10.1029/1999GL006047, 1999.
Braconnot, P., Otto-Bliesner, B., Harrison, S., Joussaume, S., Peterchmitt, J. Y., Abe-Ouchi, A., Crucifix, M., Driesschaert, E., Fichefet, T., Hewitt, C. D., Kageyama, M., Kitoh, A., Laîné, A., Loutre, M.-F., Marti, O., Merkel, U., Ramstein, G., Valdes, P., Weber, S. L., Yu, Y., and Zhao, Y.: Results of PMIP2 coupled simulations of the Mid-Holocene and Last Glacial Maximum – Part 1: experiments and large-scale features, Clim. Past, 3, 261–277, https://doi.org/10.5194/cp-3-261-2007, 2007.
Braconnot, P., Albani, S., Balkanski, Y., Cozic, A., Kageyama, M., Sima, A.,
Marti, O., and Peterschmitt, J.-Y.: Impact of dust in PMIP-CMIP6 mid-Holocene simulations with the IPSL model, Clim. Past, 17, 1091–1117,
https://doi.org/10.5194/cp-17-1091-2021, 2021.
Brierley, C. M., Zhao, A., Harrison, S. P., Braconnot, P., Williams, C. J.,
Thornalley, D. J. R., Shi, X., Peterschmitt, J.-Y., Ohgaito, R., Kaufman, D.
S., Kageyama, M., Hargreaves, J. C., Erb, M. P., Emile-Geay, J., D'Agostino,
R., Chandan, D., Carré, M., Bartlein, P. J., Zheng, W., Zhang, Z., Zhang, Q., Yang, H., Volodin, E. M., Tomas, R. A., Routson, C., Peltier, W. R., Otto-Bliesner, B., Morozova, P. A., McKay, N. P., Lohmann, G., Legrande, A. N., Guo, C., Cao, J., Brady, E., Annan, J. D., and Abe-Ouchi, A.: Large-scale features and evaluation of the PMIP4-CMIP6 midHolocene simulations, Clim. Past, 16, 1847–1872, https://doi.org/10.5194/cp-16-1847-2020, 2020.
Broström, A., Coe, M., Harrison, S. P., Gallimore, R., Kutzbach, J. E.,
Foley, J., Prentice, I. C., and Behling, P.: Land surface feedbacks and
palaeomonsoons in northern Africa, Geophys. Res. Lett., 25, 3615–3618,
https://doi.org/10.1029/98gl02804, 1998.
Budyko, M. I. and Miller, D. H. (Eds.): Climate and life, Academic Press, New York, ISBN 0121394506, 1974.
Carrington, D. P., Gallimore, R. G., and Kutzbach, J. E.: Climate sensitivity to wetlands and wetland vegetation in mid-Holocene North Africa, Clim. Dynam., 17, 151–157, https://doi.org/10.1007/s003820000099, 2001.
Cauquoin, A., Werner, M., and Lohmann, G.: Water isotopes – climate relationships for the mid-Holocene and preindustrial period simulated with
an isotope-enabled version of MPI-ESM, Clim. Past, 15, 1913–1937, https://doi.org/10.5194/cp-15-1913-2019, 2019.
Chandan, D. and Peltier, W. R.: African Humid Period Precipitation Sustained by Robust Vegetation, Soil, and Lake Feedbacks, Geophys. Res. Lett., 47, e2020GL088728, https://doi.org/10.1029/2020gl088728, 2020.
Cheddadi, R., Carre, M., Nourelbait, M., Francois, L., Rhoujjati, A., Manay,
R., Ochoa, D., and Schefuß, E.: Early Holocene greening of the Sahara requires Mediterranean winter rainfall, P. Natl. Acad. Sci. USA, 118, e2024898118, https://doi.org/10.1073/pnas.2024898118, 2021.
Chen, W.: Wetlands of North African during mid-Holocene, Mendeley Data [data set], https://doi.org/10.17632/8vfhhv8s2f.1, 2021.
Chen, W., Ciais, P., Zhu, D., Ducharne, A., Viovy, N., Qiu, C., and Huang, C.: Feedbacks of soil properties on vegetation during the Green Sahara
period, Quaternary Sci. Rev., 240, 106389, https://doi.org/10.1016/j.quascirev.2020.106389, 2020.
Chen, W., Ciais, P., Qiu, C., Ducharne, A., Zhu, D., Peng, S., Braconnot, P., and Huang, C.: Wetlands of North Africa During the Mid-Holocene Were at Least Five Times the Area Today. Geophys. Res. Lett., 48, e2021GL094194,
https://doi.org/10.1029/2021gl094194, 2021.
Claussen, M., Dallmeyer, A., and Bader, J.: Theory and Modeling of the African Humid Period and the Green Sahara, in: Oxford Research Encyclopedia of Climate Science, Oxford University Press, https://doi.org/10.1093/acrefore/9780190228620.013.532, 2017.
Comas-Bru, L., Harrison, S. P., Werner, M., Rehfeld, K., Scroxton, N., Veiga-Pires, C., and S. W. G. members: Evaluating model outputs using
integrated global speleothem records of climate change since the last
glacial, Clim. Past, 15, 1557–1579, https://doi.org/10.5194/cp-15-1557-2019, 2019.
Comas-Bru, L., Rehfeld, K., Roesch, C., Amirnezhad-Mozhdehi, S., Harrison,
S. P., Atsawawaranunt, K., Ahmad, S. M., Brahim, Y. A., Baker, A., Bosomworth, M., Breitenbach, S. F. M., Burstyn, Y., Columbu, A., Deininger,
M., Demény, A., Dixon, B., Fohlmeister, J., Hatvani, I. G., Hu, J.,
Kaushal, N., Kern, Z., Labuhn, I., Lechleitner, F. A., Lorrey, A., Martrat,
B., Novello, V. F., Oster, J., Pérez-Mejías, C., Scholz, D., Scroxton, N., Sinha, N., Ward, B. M., Warken, S., Zhang, H., and SISAL Working Group members: SISALv2: a comprehensive speleothem isotope database
with multiple age–depth models, Earth Syst. Sci. Data, 12, 2579–2606,
https://doi.org/10.5194/essd-12-2579-2020, 2020a.
Comas-Bru, L., Atsawawaranunt, K., Harrison, S., and SISAL working group members: SISAL (Speleothem Isotopes Synthesis and AnaLysis Working Group) database version 2.0, University of Reading [data set], https://doi.org/10.17864/1947.256, 2020b.
Dallmeyer, A., Claussen, M., Lorenz, S. J., and Shanahan, T.: The end of the
African humid period as seen by a transient comprehensive Earth system model
simulation of the last 8000 years, Clim. Past, 16, 117–140,
https://doi.org/10.5194/cp-16-117-2020, 2020.
Duque-Villegas, M., Claussen, M., Brovkin, V., and Kleinen, T.: Effects of
orbital forcing, greenhouse gases and ice sheets on Saharan greening in past
and future multi-millennia, Clim. Past, 18, 1897–1914, https://doi.org/10.5194/cp-18-1897-2022, 2022.
Fudge, T. J., Steig, E. J., Markle, B. R., Schoenemann, S. W., Ding, Q., Taylor, K. C., and W. D. P. Members: Onset of deglacial warming in West
Antarctica driven by local orbital forcing, Nature, 500, 440–444,
https://doi.org/10.1038/nature12376, 2013.
Gasse, F.: Hydrological changes in the African tropics since the Last Glacial Maximum. Quaternary Sci. Rev., 19, 189–211, https://doi.org/10.1016/S0277-3791(99)00061-X, 2000.
Harrison, S. P., Bartlein, P. J., Izumi, K., Li, G., Annan, J., Hargreaves,
J., Braconnot, P., and Kageyama, M.: Evaluation of CMIP5 palaeo-simulations
to improve climate projections, Nat. Clim. Change, 5, 735–743,
https://doi.org/10.1038/nclimate2649, 2015.
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,
https://doi.org/10.1029/97gb02733, 1998.
Holmes, J. and Hoelzmann, P.: The late pleistocene-holocene African humid
period as evident in lakes, in: Oxford Research Encyclopedia of Climate
Science, Oxford University Press, https://doi.org/10.1093/acrefore/9780190228620.013.531, 2017.
Hopcroft, P. O. and Valdes, P. J.: On the Role of Dust-Climate Feedbacks
During the Mid-Holocene, Geophys. Res. Lett., 46, 1612–1621,
https://doi.org/10.1029/2018gl080483, 2019.
Joly, M. and Voldoire, A.: Influence of ENSO on the West African Monsoon:
Temporal Aspects and Atmospheric Processes, J. Climate, 22, 3193–3210,
https://doi.org/10.1175/2008JCLI2450.1, 2009.
Kino, K., Okazaki, A., Cauquoin, A., and Yoshimura, K.: Contribution of the
Southern Annular Mode to Variations in Water Isotopes of Daily Precipitation
at Dome Fuji, East Antarctica, J. Geophys. Res.-Atmos., 126, e2021JD035397,
https://doi.org/10.1029/2021JD035397, 2021.
Klein, C., Heinzeller, D., Bliefernicht, J., and Kunstmann, H.: Variability
of West African monsoon patterns generated by a WRF multi-physics ensemble,
Clim. Dynam., 45, 2733–2755, https://doi.org/10.1007/s00382-015-2505-5, 2015.
Krinner, G., Lézine, 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.
Kuete, G., Mba, W. P., James, R., Dyer, E., Annor, T., and Washington, R.:
How do coupled models represent the African Easterly Jets and their associated dynamics over Central Africa during the September–November rainy
season?, Clim. Dynam., 60, 2907–2929, https://doi.org/10.1007/s00382-022-06467-y, 2022.
Kutzbach, J., Bonan, G., Foley, J., and Harrison, S. P.: Vegetation and soil
feedbacks on the response of the African monsoon to orbital forcing in the
early to middle Holocene, Nature, 384, 623–626, https://doi.org/10.1038/384623a0, 1996.
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, https://doi.org/10.1126/science.278.5337.440, 1997.
Kutzbach, J. E., Guan, J., He, F., Cohen, A. S., Orland, I. J., and Chen, G.: African climate response to orbital and glacial forcing in 140,000-y simulation with implications for early modern human environments, P. Natl. Acad. Sci. USA, 117, 2255–2264, https://doi.org/10.1073/pnas.1917673117, 2020.
Larrasoaña, J. C., Roberts, A. P., and Rohling, E. J.: Dynamics of green
Sahara periods and their role in hominin evolution, PloS One, 8, e76514,
https://doi.org/10.1371/journal.pone.0076514, 2013.
Lavaysse, C., Flamant, C., and Janicot, S.: Regional-scale convection patterns during strong and weak phases of the Saharan heat low, Atmos. Sci.
Lett., 11, 255–264, https://doi.org/10.1002/asl.284, 2010.
Liu, X., Xie, X., Guo, Z., Yin, Z. Y., and Chen, G.: Model-based distinct
characteristics and mechanisms of orbital-scale precipitation δ18O
variations in Asian monsoon and arid regions during late Quaternary, Natl.
Sci. Rev., 9, nwac182, https://doi.org/10.1093/nsr/nwac182, 2022.
Messori, G., Gaetani, M., Zhang, Q., Zhang, Q., and Pausata, F. S. R.: The
water cycle of the mid-Holocene West African monsoon: The role of vegetation
and dust emission changes, Int. J. Climatol., 39, 1927–1939,
https://doi.org/10.1002/joc.5924, 2018.
National Geophysical Data Center: 5-minute Gridded Global Relief Data (ETOPO5) National Geophysical Data Center, NOAA [data set], https://doi.org/10.7289/V5D798BF, 1993.
Ngoungue Langue, C. G., Lavaysse, C., Vrac, M., Peyrillé, P., and Flamant, C.: Seasonal forecasts of the Saharan heat low characteristics: a
multi-model assessment, Weather Clim. Dynam., 2, 893–912,
https://doi.org/10.5194/wcd-2-893-2021, 2021.
Nicholson, S. E.: On the factors modulating the intensity of the tropical
rainbelt over West Africa, Int. J. Climatol., 29, 673–689, https://doi.org/10.1002/joc.1702, 2009.
Nicholson, S. E. and Klotter, D.: The Tropical Easterly Jet over Africa, its representation in six reanalysis products, and its association with Sahel rainfall, Int. J. Climatol., 41, 328–347, https://doi.org/10.1002/joc.6623, 2020.
Ohgaito, R., Yamamoto, A., Hajima, T., O'ishi, R., Abe, M., Tatebe, H., Abe-Ouci, A., and Kawamiya, M.: PMIP4 experiments using MIROC-ES2L Earth
system model, Geosci. Model Dev., 14, 1195–1217, https://doi.org/10.5194/gmd-14-1195-2021, 2021.
O'Ishi, R. and Abe-Ouchi, A.: Polar amplification in the mid-Holocene derived from dynamical vegetation change with a GCM, Geophys. Res. Lett., 38, L14702, https://doi.org/10.1029/2011gl048001, 2011.
Okazaki, A. and Yoshimura, K.: Global Evaluation of Proxy System Models for
Stable Water Isotopes With Realistic Atmospheric Forcing, J. Geophys. Res.-Atmos., 124, 8972–8993, https://doi.org/10.1029/2018jd029463, 2019 (code available at http://isotope.iis.u-tokyo.ac.jp:8000/gitlab/miroc-iso/miroc5-iso, last access: 15 May 2022).
Otto-Bliesner, B. L., Braconnot, P., Harrison, S. P., Lunt, D. J., Abe-Ouchi, A., Albani, S., Bartlein, P. J., Capron, E., Carlson, A. E., Dutton, A., Fischer, H., Goelzer, H., Govin, A., Haywood, A., Joos, F., LeGrande, A. N., Lipscomb, W. H., Lohmann, G., Mahowald, N., Nehrbass-Ahles, C., Pausata, F. S. R., Peterschmitt, J.-Y., Phipps, S. J., Renssen, H., and Zhang, Q.: The PMIP4 contribution to CMIP6 – Part 2: Two interglacials, scientific objective and experimental design for Holocene and Last Interglacial simulations, Geosci. Model Dev., 10, 3979–4003, https://doi.org/10.5194/gmd-10-3979-2017, 2017.
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.
Quade, J., Dente, E., Armon, M., Ben Dor, Y., Morin, E., Adam, O., and Enzel, Y.: Megalakes in the Sahara? A Review, Quatern. Res., 90, 253–275,
https://doi.org/10.1017/qua.2018.46, 2018.
Risi, C., Bony, S., Vimeux, F., and Jouzel, J.: Water-stable isotopes in the
LMDZ4 general circulation model: Model evaluation for present-day and past
climates and applications to climatic interpretations of tropical isotopic
records, J. Geophys. Res.-Atmos., 115, D12118, https://doi.org/10.1029/2009JD013255, 2010.
Schmidt, G. A., LeGrande, A. N., and Hoffmann, G.: Water isotope expressions
of intrinsic and forced variability in a coupled ocean-atmosphere model, J.
Geophys. Res., 112, D10103, https://doi.org/10.1029/2006JD007781, 2007.
Specht, N. F., Claussen, M., and Kleinen, T.: Simulated range of mid-Holocene precipitation changes from extended lakes and wetlands over North Africa, Clim. Past, 18, 1035–1046, https://doi.org/10.5194/cp-18-1035-2022, 2022 (data available at http://hdl.handle.net/21.11116/0000-0009-63B5-B, last access: 13 May 2022).
Steinig, S., Harlaß, J., Park, W., and Latif, M.: Sahel rainfall strength and onset improvements due to more realistic Atlantic cold tongue development in a climate model, Sci. Rep., 8, 2569, https://doi.org/10.1038/s41598-018-20904-1, 2018.
Sundqvist, H. S., Kaufman, D. S., McKay, N. P., Balascio, N. L., Briner, J.
P., Cwynar, L. C., Sejrup, H. P., Seppä, H., Subetto, D. A., Andrews, J.
T., Axford, Y., Bakke, J., Birks, H. J. B., Brooks, S. J., de Vernal, A.,
Jennings, A. E., Ljungqvist, F. C., Rühland, K. M., Saenger, C., Smol,
J. P., and Viau, A. E.: Arctic Holocene proxy climate database – new approaches to assessing geochronological accuracy and encoding climate
variables, Clim. Past, 10, 1605–1631, https://doi.org/10.5194/cp-10-1605-2014, 2014.
Takata, K., Emori, S., and Watanabe, T.: Development of the minimal advanced
treatments of surface interaction and runoff, Global Planet. Change, 38,
209–222, https://doi.org/10.1016/S0921-8181(03)00030-4, 2003.
Tegen, I., Harrison, S. P., Kohfeld, K., Prentice, I. C., Coe, M., and Heimann, M.: Impact of vegetation and preferential source areas on global
dust aerosol: Results from a model study, J. Geophys. Res.-Atmos., 107,
4576, https://doi.org/10.1029/2001jd000963, 2002.
Tharammal, T., Bala, G., Paul, A., Noone, D., Contreras-Rosales, A., and
Thirumalai, K.: Orbitally driven evolution of Asian monsoon and stable water
isotope ratios during the Holocene: Isotope-enabled climate model
simulations and proxy data comparisons, Quaternary Sci. Rev., 252, 106743,
https://doi.org/10.1016/j.quascirev.2020.106743, 2021.
Thiery, W., Davin, E. L., Panitz, H.-J., Demuzere, M., Lhermitte, S., and
van Lipzig, N.: The Impact of the African Great Lakes on the Regional
Climate, J. Climate, 28, 4061–4085, https://doi.org/10.1175/jcli-d-14-00565.1, 2015.
Thompson, A. J., Zhu, J., Poulsen, C. J., Tierney, J. E., and Skinner, C. B.: Northern Hemisphere vegetation change drives a Holocene thermal maximum, Sci. Adv., 8, eabj6535, https://doi.org/10.1126/sciadv.abj6535, 2022.
Thorncroft, C. D., Nguyen, H., Zhang, C., and Peyrillé, P.: Annual cycle
of the West African monsoon: regional circulations and associated water
vapour transport, Q. J. Roy. Meteorol. Soc., 137, 129–147, https://doi.org/10.1002/qj.728, 2011.
Tootchi, A., Jost, A., and Ducharne, A.: Multi-source global wetland maps
combining surface water imagery and groundwater constraints, Earth Syst.
Sci. Data, 11, 189–220, https://doi.org/10.5194/essd-11-189-2019, 2019.
Watanabe, M., Suzuki, T., O'ishi, R., Komuro, Y., Watanabe, S., Emori, S.,
Takemura, T., Chikira, M., Ogura, T., Sekiguchi, M., Takata, K., Yamazaki, D., Yokohata, T., Nozawa, T., Hasumi, H., Tatebe, H., and Kimoto, M.: Improved Climate Simulation by MIROC5: Mean States, Variability, and Climate
Sensitivity, J. Climate, 23, 6312–6335, https://doi.org/10.1175/2010jcli3679.1, 2010.
Zhao, Y., Braconnot, P., Marti, O., Harrison, S. P., Hewitt, C., Kitoh, A., Liu, Z., Mikolajewicz, U., Otto-Bilesmer, B., and Weber, S. L.: 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, https://doi.org/10.1007/s00382-005-0075-7, 2005.
Short summary
Our study using the isotope-enabled climate model MIROC5-iso model shows that lakes may have contributed to the Green Sahara during the mid-Holocene period (6000 years ago). The lakes induced cyclonic circulation response, enhancing the near-surface monsoon westerly flow and potentially humidifying the northwestern Sahara with the stronger West African Monsoon moving northward. Our findings provide valuable insights into understanding the presence of the Green Sahara during this period.
Our study using the isotope-enabled climate model MIROC5-iso model shows that lakes may have...
