The project’s multidisciplinary team made important contributions in several areas, including: (1) the integration of historical data from a wealth of different archives, to detail and explain the connections between climate variability, social unrest, and institutional change during the Ptolemaic era in Egypt, 305-30 BCE (e.g., McConnell et al., 2020; Ludlow and Manning, 2021; Izdebski et al., 2022) and; (2) improved understanding of global and regional (including Nile Basin) climatic and hydrological responses to volcanic eruptions (e.g., McConnell et al., 2020; Singh et al., 2023).

A graduate student at Yale working on the project, Joe Morgan, led the creation of a database of both Greek and Egyptian language sources that is five times larger and covers nearly every year of the Ptolemaic period. A key feature of this database is the geocoding of most of the sources, allowing their mapping and (for the first time) integration with a hydrological model of the floodplain.

Model simulations show that commonly flooded areas neatly surrounded most recorded locations of interest during the Ptolemaic period, providing some historical validation (Fig. 1). Flood simulations also showed that agriculture in the Thebaid, the upstream portion of the Egyptian Nile, would have been more sensitive to moderate droughts (Figs. 1 and 2). The downstream Nile, while relatively unaffected during moderate droughts, would have experienced catastrophic loss of irrigated land only during the most severe droughts. Climate simulations by the project team show that the four large and closely timed volcanic eruptions occurring between 168 and 158 BCE would have produced several severe drought years,

A hydrologic model ("Nile River basin) was calibrated using a series of recovered hydrologic records. Manuscripts explaining the calibration of the model and the digitization of hydrologic records are currently being developed.

A computationally inexpensive coupling framework has been developed and implemented in the NASA GISS ModelE to account for vegetation–climate feedbacks during the 2.5 ka period (Singh et al., 2024). This work explores the importance of various performance metrics that can influence vegetation–climate feedbacks and evaluates a set of control climate conditions for the 2.5 ka period against multiproxy paleoclimate reconstructions. Additional ongoing efforts focus on examining the sensitivity of regional climate to various land-use and land-cover changes and using a crop model to analyze the impacts of NASA GISS model–simulated climate conditions on crop yield.

Hundreds of school children from New Haven visit the museum and begin their tour right in front of our display (Public Display).

Izdebski, A., Bloomfield, K., Eastwood, W. J., Fernandes, R., Fleitmann, D., Guzowski, P., Haldon, J., Ludlow, F., Luterbacher, J., Manning, J. G., Masi, A., Mordechai, L., Newfield, T. P., Stine, A. R., Senkul, C. and Xoplaki, E. (2022), "The Emergence of Interdisciplinary Environmental History: Bridging the Gap between the Humanistic and Scientific Approaches to the Late Holocene," Annales, 77(1), 11-58. DOI:10.1017/ahss.2022.114

Ludlow, F. and Manning, J. G. (2021) “Volcanic Eruptions, Veiled Suns, and Nile Failure in Egyptian History: Integrating Hydroclimate into Understandings of Historical Change”, In: Erdkamp, P., Manning, J. G. and Verboven K. (eds.), Climate Change and Ancient Societies in Europe and the Near East: Diversity in Collapse and Resilience. London: Palgrave Macmillan, 301-320. DOI: 10.1007/978-3-030-81103-7_10

Manning, J. G., Ludlow, F., Stine, A. R. Boos, W., Sigl, M. and Marlon, J. (2017) “Volcanic Suppression of Nile Summer Flooding Triggers Revolt and Constrains Interstate Conflict in Ancient Egypt”, Nature Communications, 8, Article 900. doi: 10.1038/s41467-017-00957-y

McConnell, J. R., et al. (2020) “Extreme Climate after Massive Eruption of Alaska’s Okmok Volcano in 43 BCE and Effects on the late Roman Republic and Ptolemaic Kingdom”, Proceedings of the National Academy of Sciences, 117 (27), 15443-15449. DOI:10.1073/pnas.2002722117

Sigl, M., Winstrup, M., McConnell, J.R., Welten, K.C., Plunkett, G., Ludlow, F., Büntgen, U., Caffee, M., Chellman, N., Dahl-Jensen, D., Fischer, H., Kipfstuhl, S., Kostick, C., Maselli, O.J., Mekhaldi, F., Mulvaney, R., Muscheler, R., Pasteri, D.R., Pilcher, J.R., Salzer, M., Schüpbach, S., Steffensen, J.P., Vinther, B., Woodruff, T.E. (2015) "Timing and Climate Forcing of Volcanic Eruptions during the Past 2,500 years", Nature, 523, 543-549, doi:10.1038/nature14565.

Singh, R., Kostas, T., LeGrande, A. N., Ludlow, F. and Manning, J. G. (2023) “Investigating Hydroclimatic Impacts of the 168–158 BCE Volcanic Quartet and their Relevance to the Nile River Basin and Egyptian History”, Climate of the Past, 19 (1), 249-275. DOI:10.5194/cp-19-249-2023.

Singh, R., Koch, A., LeGrande, A. N., Tsigaridis, K., Ramos, R. D., Ludlow, F., Aleinov, I., Ruedy, R., and Kaplan, J. O. (2024): Modelling framework for asynchronous land-atmosphere coupling using NASA GISS ModelE and LPJ-LMfire: Design, Application and Evaluation for the 2.5ka period. Geosci. Model Dev. Discuss. [preprint], https://doi.org/10.5194/gmd-2024-219, in review, 2024.

Last Modified: 02/17/2025
Modified by: Joseph G Manning