Simulating the mid-Holocene, Last Interglacial and mid-Pliocene climate with EC-Earth3-LR

Abstract

Abstract. Paleoclimate modelling has long been regarded as a strong out-of-sample test-bed of the climate models that are used for the projection of future climate changes. For the first time, the EC-Earth model contributes to the Paleoclimate Model Intercomparison Project (PMIP) phase 4, which is part of the current sixth phase of the Coupled Model Intercomparison Project (CMIP6). Here, we document the model setup for PMIP4 experiments with EC-Earth3-LR and present the results on the large-scale features from the completed production simulations for the three past warm periods (mid-Holocene, Last Interglacial, and mid-Pliocene). Using the pre-industrial climate as a reference state, we show the changes in global temperature, large scale Hadley circulation and Walker circulation, polar warming and global monsoons, as well as the climate variability modes (ENSO, PDO, AMO). The EC-Earth3-LR simulates reasonable climate responses during past warm periods as shown in the other PMIP4-CMIP6 model ensemble. The systematic comparison of these climate changes in three past warm periods in an individual model demonstrates the ability of the model to capture the climate response under different climate forcings, providing potential implications for confidence in future projections with EC-Earth model.

Evaluating the large-scale hydrological cycle response within the Pliocene Model Intercomparison Project Phase 2 (PlioMIP2) ensemble

“…Additionally, the expansion of vegetation into the Sahara region tends to decrease the surface albedo, which can enhance the Saharan heat low and, hence, impact rainfall over West Africa, reflecting the vegetation-albedo feedback (Charney, 1975). Recent studies indicate that the enhanced vegetation in the PlioMIP2 ensemble is likely to have contributed to increased mid-Pliocene West African summer rainfall (Haywood et al, 2020;Berntell et al, 2021). This change over Southeast Asia is robust among PlioMIP2 models, and only the COSMOS model shows a drier change over East Asia (Fig.…”

EC‐Earth Simulations Reveal Enhanced Inter‐Hemispheric Thermal Contrast During the Last Interglacial Further Intensified the Indian Monsoon

“…Through model intercomparisons, EC‐Earth3‐LR simulates a positive temperature bias in the Arctic region during LIG, hence a weaker boreal latitudinal temperature gradient compared to other PMIP4 model simulations, while the simulated southern hemisphere latitudinal temperature gradient is close to the PMIP4 ensemble mean (Otto‐Bliesner et al., 2021). Negative surface temperature responses in the Indian Monsoon region are similar in the range between EC‐Earth3‐LR and ensemble mean (Otto‐Bliesner et al., 2021; Zhang et al., 2021). Global monsoons in the EC‐Earth3‐LR simulations have also been evaluated in Zhang et al.…”

Intensified Atmospheric Branch of the Hydrological Cycle Over the Tibetan Plateau During the Last Interglacial From a Dynamical Downscaling Perspective

“…They noted that variations in precipitation resulted from the movement of the convergence belt in response to changes in insolation. This mechanism was confirmed by a series of studies using different global climate models at various resolutions, although with discrepancies in the changing magnitude in precipitation (high‐value centers for increased precipitation ranging from 1 mm d −1 to 6 mm d −1 ) (Kubatzki et al., 2000; Montoya et al., 2000; Nikolova et al., 2013; O'Ishi et al., 2021; Otto‐Bliesner et al., 2020; Pedersen et al., 2016; Timm et al., 2008; Zhang et al., 2020). Scussolini et al.…”