scholarly journals The ENEA-REG system (v1.0), a multi-component regional earth system model. Sensitivity to different atmospheric component over Med-CORDEX region

2021 ◽  
Author(s):  
Alessandro Anav ◽  
Adriana Carillo ◽  
Massimiliano Palma ◽  
Maria Vittoria Struglia ◽  
Ufuk Utku Turuncoglu ◽  
...  
Keyword(s):  
Land Surface ◽  
Large Scale ◽  
Mediterranean Climate ◽  
Climate Models ◽  
Ocean Model ◽  
Earth System Model ◽  
System Model ◽  
Cold Bias ◽  
Earth System ◽  
Atmospheric Component

Abstract. In this study, a new regional Earth system model is developed and applied to the Med-CORDEX region. The ENEA-REG system is made up of two interchangeable regional climate models as atmospheric components (RegCM and WRF), a river model (HD), and an ocean model (MITgcm); processes taking place at the land surface are represented within the atmospheric models with the possibility to use several land surface schemes of different complexity. The coupling between these components is performed through the RegESM driver. Here, we present and describe our regional Earth system model and evaluate its components using a multidecadal hindcast simulation over the period 1980–2013 driven by ERA-INTERIM reanalysis. We show how the atmospheric components are able to correctly reproduce both large-scale and local features of the Euro-Mediterranean climate, although some remarkable biases are relevant for some variables. In particular, WRF has a significant cold bias during winter over North-Eastern bound of the domain, while RegCM systematically overestimates the wind speed over the Mediterranean Sea. This latter bias has severe consequences on the ocean component: we show that when WRF is used as the atmospheric component of the Earth system, the performances of the ocean model are remarkably better compared with the RegCM version. Our regional Earth system model allows studying the Euro-Mediterranean climate system and can be applied to both hindcast and scenario simulations.

scholarly journals Snowball Earth Bifurcations in a Fully-Implicit Earth System Model

2021 ◽  
Vol 31 (06) ◽  
pp. 2130017
Author(s):  
Thomas E. Mulder ◽  
Heiko Goelzer ◽  
Fred W. Wubs ◽  
Henk A. Dijkstra
Keyword(s):  
Large Scale ◽  
Climate Models ◽  
Ocean Model ◽  
Earth System Model ◽  
System Model ◽  
Snowball Earth ◽  
Earth System ◽  
Geological Evidence ◽  
Fully Implicit ◽  
Additional Support

There is now much geological evidence that the Earth was fully glaciated during several periods in the geological past (about 700[Formula: see text]Myr ago) and attained a so-called Snowball Earth (SBE) state. Additional support for this idea has come from climate models of varying complexity that show transitions to SBE states and undergo hysteresis under changes in solar radiation. In this paper, we apply large-scale bifurcation analyses to a novel, fully-implicit Earth System Model of Intermediate Complexity (I-EMIC) to study SBE transitions. The I-EMIC contains a primitive equation ocean model, a model for atmospheric heat and moisture transport, a sea ice component and formulations for the adjustment of albedo over snow and ice. With the I-EMIC, high-dimensional branches of the SBE bifurcation diagram are obtained through parameter continuation. We are able to identify stable and unstable equilibria and uncover an intricate bifurcation structure associated with the ice-albedo feedback. Moreover, large-scale linear stability analyses are performed near major bifurcations, revealing the spatial nature of destabilizing perturbations.

scholarly journals The Canadian Earth System Model version 5 (CanESM5.0.3)

2019 ◽  
Vol 12 (11) ◽  
pp. 4823-4873 ◽  
Author(s):  
Neil C. Swart ◽  
Jason N. S. Cole ◽  
Viatcheslav V. Kharin ◽  
Mike Lazare ◽  
John F. Scinocca ◽  
...  
Keyword(s):  
Land Surface ◽  
General Circulation ◽  
Large Scale ◽  
General Circulation Models ◽  
Earth System Model ◽  
System Model ◽  
Historical Period ◽  
Earth System ◽  
Historical Climate ◽  
Model Version

Abstract. The Canadian Earth System Model version 5 (CanESM5) is a global model developed to simulate historical climate change and variability, to make centennial-scale projections of future climate, and to produce initialized seasonal and decadal predictions. This paper describes the model components and their coupling, as well as various aspects of model development, including tuning, optimization, and a reproducibility strategy. We also document the stability of the model using a long control simulation, quantify the model's ability to reproduce large-scale features of the historical climate, and evaluate the response of the model to external forcing. CanESM5 is comprised of three-dimensional atmosphere (T63 spectral resolution equivalent roughly to 2.8∘) and ocean (nominally 1∘) general circulation models, a sea-ice model, a land surface scheme, and explicit land and ocean carbon cycle models. The model features relatively coarse resolution and high throughput, which facilitates the production of large ensembles. CanESM5 has a notably higher equilibrium climate sensitivity (5.6 K) than its predecessor, CanESM2 (3.7 K), which we briefly discuss, along with simulated changes over the historical period. CanESM5 simulations contribute to the Coupled Model Intercomparison Project phase 6 (CMIP6) and will be employed for climate science and service applications in Canada.

scholarly journals The Canadian Earth System Model version 5 (CanESM5.0.3)

2019 ◽  
Author(s):  
Neil C. Swart ◽  
Jason N. S. Cole ◽  
Viatcheslav V. Kharin ◽  
Mike Lazare ◽  
John F. Scinocca ◽  
...  
Keyword(s):  
Land Surface ◽  
General Circulation ◽  
Large Scale ◽  
General Circulation Models ◽  
Earth System Model ◽  
System Model ◽  
Historical Period ◽  
Earth System ◽  
Historical Climate ◽  
Model Version

Abstract. The Canadian Earth System Model version 5 (CanESM5) is a global model developed to simulate historical climate change and variability, to make centennial scale projections of future climate, and to produce initialized seasonal and decadal predictions. This paper describes the model components and their coupling, as well as various aspects of model development, including tuning, optimization and a reproducibility strategy. We also document the stability of the model using a long control simulation, quantify the model's ability to reproduce large scale features of the historical climate, and evaluate the response of the model to external forcing. CanESM5 is comprised of three dimensional atmosphere (T63 spectral resolution/2.8°) and ocean (nominally 1°) general circulation models, a sea ice model, a land surface scheme, and explicit land and ocean carbon cycle models. The model features relatively coarse resolution and high throughput, which facilitates the production of large ensembles. CanESM5 has a notably higher equilibrium climate sensitivity (5.7 K) than its predecessor CanESM2 (3.8 K), which we briefly discuss, along with simulated changes over the historical period. CanESM5 simulations are contributing to the Coupled Model Intercomparison Project Phase 6 (CMIP6), and will be employed for climate science and service applications in Canada.

scholarly journals Combined biogeophysical and biogeochemical effects of large-scale forest cover changes in the MPI earth system model

2010 ◽  
Vol 7 (1) ◽  
pp. 387-428 ◽  
Author(s):  
S. Bathiany ◽  
M. Claussen ◽  
V. Brovkin ◽  
T. Raddatz ◽  
V. Gayler
Keyword(s):  
Land Surface ◽  
Large Scale ◽  
Forest Canopy ◽  
Forest Cover ◽  
Co2 Concentration ◽  
Earth System Model ◽  
System Model ◽  
Climate Mitigation ◽  
Earth System ◽  
The Tropics

Abstract. Afforestation and reforestation have become popular instruments of climate mitigation policy, as forests are known to store large quantities of carbon. However, they also modify the fluxes of energy, water and momentum at the land surface. Previous studies have shown that these biogeophysical effects can counteract the carbon drawdown and, in boreal latitudes, even overcompensate it due to large albedo differences between forest canopy and snow. This study investigates the role forest cover plays for global climate by conducting deforestation and afforestation experiments with the earth system model of the Max Planck Institute for Meteorology (MPI-ESM). Complete deforestation of the tropics (18.75° S–15° N) exerts a global warming of 0.4 °C due to an increase in CO2 concentration by initially 60 ppm and a decrease in evapotranspiration in the deforested areas. In the northern latitudes (45° N–90° N), complete deforestation exerts a global cooling of 0.25 °C after 100 years, while afforestation leads to an equally large warming, despite the counteracting changes in CO2 concentration. Earlier model studies are qualitatively confirmed by these findings. As the response of temperature as well as terrestrial carbon pools is not of equal sign at every land cell, considering forests as cooling in the tropics and warming in high latitudes seems to be true only for the spatial mean, but not on a local scale.

scholarly journals IPSL-CM5A2. An Earth System Model designed for multi-millennial climate simulations

2019 ◽  
Author(s):  
Pierre Sepulchre ◽  
Arnaud Caubel ◽  
Jean-Baptiste Ladant ◽  
Laurent Bopp ◽  
Olivier Boucher ◽  
...  
Keyword(s):  
Coupled Model ◽  
Ocean Model ◽  
Earth System Model ◽  
Meridional Overturning Circulation ◽  
System Model ◽  
Cold Bias ◽  
Specific Work ◽  
Earth System ◽  
Deep Time ◽  
Historical Simulation

Abstract. Based on the CMIP5-generation previous IPSL earth system model, we designed a new version, IPSL-CM5A2, aiming at running multi-millennial simulations typical of deep-time paleoclimates studies. Three priorities were followed during the set-up of the model: (1) improving the overall model computing performance, (2) overcoming a persistent cold bias depicted in the previous model generation, and (3) making the model able to handle the specific continental configurations of the geological past. Technical developments have been performed on separate components and on the coupling system to speed up the whole coupled model. These developments include the integration of hybrid parallelization MPI-OpenMP in LMDz atmospheric component, the use of a new library to perform parallel asynchronous input/output by using computing cores as “IO servers”, the use of a parallel coupling library between the ocean and the atmospheric components. The model can now simulate ~100 years per day, opening new possibilities towards the production of multi-millennial simulations with a full earth system model. The tuning strategy employed to overcome a persistent cold bias is detailed. The confrontation of an historical simulation to climatological observations shows overall improved ocean meridional overturning circulation, marine productivity and latitudinal position of zonal wind patterns. We also present the numerous steps required to run the IPSL-CM5A2 for deep-time paleoclimates through a preliminary case-study for the Cretaceous. Namely, a specific work on the ocean model grid was required to run the model for specific continental configurations in which continents are relocated according to past paleogeographic reconstructions. By briefly discussing the spin-up of such a simulation, we elaborate on the requirements and challenges awaiting paleoclimate modelling in the next years, namely finding the best trade-off between the level of description of the processes and the computing cost on supercomputers.

scholarly journals Combined biogeophysical and biogeochemical effects of large-scale forest cover changes in the MPI earth system model

2010 ◽  
Vol 7 (5) ◽  
pp. 1383-1399 ◽  
Author(s):  
S. Bathiany ◽  
M. Claussen ◽  
V. Brovkin ◽  
T. Raddatz ◽  
V. Gayler
Keyword(s):  
Land Surface ◽  
Large Scale ◽  
Forest Canopy ◽  
Forest Cover ◽  
Co2 Concentration ◽  
Earth System Model ◽  
System Model ◽  
Climate Mitigation ◽  
Earth System ◽  
The Tropics

Abstract. Afforestation and reforestation have become popular instruments of climate mitigation policy, as forests are known to store large quantities of carbon. However, they also modify the fluxes of energy, water and momentum at the land surface. Previous studies have shown that these biogeophysical effects can counteract the carbon drawdown and, in boreal latitudes, even overcompensate it due to large albedo differences between forest canopy and snow. This study investigates the role forest cover plays for global climate by conducting deforestation and afforestation experiments with the earth system model of the Max Planck Institute for Meteorology (MPI-ESM). Complete deforestation of the tropics (18.75° S–15° N) exerts a global warming of 0.4 °C due to an increase in CO2 concentration by initially 60 ppm and a decrease in evapotranspiration in the deforested areas. In the northern latitudes (45° N–90° N), complete deforestation exerts a global cooling of 0.25 °C after 100 years, while afforestation leads to an equally large warming, despite the counteracting changes in CO2 concentration. Earlier model studies are qualitatively confirmed by these findings. As the response of temperature as well as terrestrial carbon pools is not of equal sign at every land cell, considering forests as cooling in the tropics and warming in high latitudes seems to be true only for the spatial mean, but not on a local scale.

scholarly journals Coupling the U.K. Earth System Model to dynamic models of the Greenland and Antarctic ice sheets

2021 ◽  
Author(s):  
Robin Smith ◽  
Pierre Mathiot ◽  
Antony Siahaan ◽  
Victoria Lee ◽  
Stephen Cornford ◽  
...  
Keyword(s):  
Land Surface ◽  
Dynamic Models ◽  
Ice Sheets ◽  
Ice Sheet ◽  
Ocean Model ◽  
Earth System Model ◽  
System Model ◽  
Surface Model ◽  
Earth System ◽  
Antarctic Ice Sheets

<p>In this presentation we describe how models of the Greenland and Antarctic ice sheets have been incorporated in the global U.K. Earth System model (UKESM1) with a two-way coupling that passes fluxes of energy, water and the locations of ice surfaces between the component models. Offline, file-based coupling is used throughout to pass information between the components, which is both physically appropriate and convenient within the UKESM1 structure. Ice sheet surface mass balance is computed in the land surface model using sub-gridscale multi-layer snowpacks. Icebergs calved from the ice sheets are fed into a Langrangian iceberg drift scheme in the ocean. Ice shelf basal melt is explicitly calculated in cavities resolved by the ocean model, and ice sheet and shelf geometries are kept consistent in all components. We demonstrate that our coupled model remains stable when simulating changes in ice sheet height, extent and grounding-line position of hundreds of kilometres.</p>

scholarly journals IPSL-CM5A2 – an Earth system model designed for multi-millennial climate simulations

2020 ◽  
Vol 13 (7) ◽  
pp. 3011-3053 ◽  
Author(s):  
Pierre Sepulchre ◽  
Arnaud Caubel ◽  
Jean-Baptiste Ladant ◽  
Laurent Bopp ◽  
Olivier Boucher ◽  
...  
Keyword(s):  
Message Passing Interface ◽  
Coupled Model ◽  
Ocean Model ◽  
Earth System Model ◽  
Meridional Overturning Circulation ◽  
System Model ◽  
Cold Bias ◽  
Specific Work ◽  
Earth System ◽  
Deep Time

Abstract. Based on the fifth phase of the Coupled Model Intercomparison Project (CMIP5)-generation previous Institut Pierre Simon Laplace (IPSL) Earth system model, we designed a new version, IPSL-CM5A2, aiming at running multi-millennial simulations typical of deep-time paleoclimate studies. Three priorities were followed during the setup of the model: (1) improving the overall model computing performance, (2) overcoming a persistent cold bias depicted in the previous model generation and (3) making the model able to handle the specific continental configurations of the geological past. These developments include the integration of hybrid parallelization Message Passing Interface – Open Multi-Processing (MPI-OpenMP) in the atmospheric model of the Laboratoire de Météorologie Dynamique (LMDZ), the use of a new library to perform parallel asynchronous input/output by using computing cores as “I/O servers” and the use of a parallel coupling library between the ocean and the atmospheric components. The model, which runs with an atmospheric resolution of 3.75∘×1.875∘ and 2 to 0.5∘ in the ocean, can now simulate ∼100 years per day, opening new possibilities towards the production of multi-millennial simulations with a full Earth system model. The tuning strategy employed to overcome a persistent cold bias is detailed. The confrontation of a historical simulation to climatological observations shows overall improved ocean meridional overturning circulation, marine productivity and latitudinal position of zonal wind patterns. We also present the numerous steps required to run IPSL-CM5A2 for deep-time paleoclimates through a preliminary case study for the Cretaceous. Namely, specific work on the ocean model grid was required to run the model for specific continental configurations in which continents are relocated according to past paleogeographic reconstructions. By briefly discussing the spin-up of such a simulation, we elaborate on the requirements and challenges awaiting paleoclimate modeling in the next years, namely finding the best trade-off between the level of description of the processes and the computing cost on supercomputers.

scholarly journals Neodymium isotopes in the ocean model of the Community Earth System Model (CESM1.3)

2017 ◽  
Author(s):  
Sifan Gu ◽  
Zhengyu Liu ◽  
Alexandra Jahn ◽  
Johannes Rempfer ◽  
Jiaxu Zhang ◽  
...  
Keyword(s):  
Ocean Circulation ◽  
Climate Models ◽  
Marine Ecosystem ◽  
Ocean Model ◽  
Earth System Model ◽  
System Model ◽  
Earth System ◽  
Promising Tool ◽  
Boundary Source ◽  
Community Earth System Model

Abstract. Neodymium (Nd) isotope ratio (εNd) is a quasi-conservative water mass tracer and has been used increasingly as paleoclimate proxy to indicate the past evolution of ocean circulation. However, there are many uncertainties in interpreting εNd reconstructions. For the purposes of direct comparison between climate models and proxy reconstructions, we implement Nd isotopes (143Nd and 144Nd) in the ocean model of the Community Earth System Model (CESM). Two versions of Nd tracers are implemented: one is the "abiotic" Nd in which the particle fields are prescribed as the particle climatology generated by the marine ecosystem module of the CESM under present day forcing; the other is the "biotic" Nd that is coupled with the marine ecosystem module. Under present day climate forcing, our model is able to simulate both Nd concentrations and εNd in good agreement with available observations. Also, Nd concentration and εNd in our model show similar sensitivities to the total boundary source and the ratio between particle related Nd and dissolved Nd as in previous modeling study (Rempfer et al., 2011). Therefore, our Nd-enabled ocean model provides a promising tool to study past changes in ocean and climate.

scholarly journals Simulations of the Mid-Pliocene Warm Period using the NASA/GISS ModelE2-R Earth System Model

2012 ◽  
Vol 5 (3) ◽  
pp. 2811-2842 ◽  
Author(s):  
M. A. Chandler ◽  
L. E. Sohl ◽  
J. A. Jonas ◽  
H. J. Dowsett
Keyword(s):  
North Atlantic ◽  
Climate Models ◽  
Climate Model ◽  
Geographic Region ◽  
Earth System Model ◽  
Warm Period ◽  
System Model ◽  
Earth System ◽  
Intergovernmental Panel ◽  
Future Global Warming

Abstract. Climate reconstructions of the mid-Pliocene Warm Period (mPWP) bear many similarities to aspects of future global warming as projected by the Intergovernmental Panel on Climate Change. In particular, marine and terrestrial paleoclimate data point to high latitude temperature amplification, with associated decreases in sea ice and land ice and altered vegetation distributions that show expansion of warmer climate biomes into higher latitudes. NASA GISS climate models have been used to study the Pliocene climate since the USGS PRISM project first identified that the mid-Pliocene North Atlantic sea surface temperatures were anomalously warm. Here we present the most recent simulations of the Pliocene using the AR5/CMIP5 version of the GISS Earth System Model known as ModelE2-R. These simulations constitute the NASA contribution to the Pliocene Model Intercomparison Project (PlioMIP) Experiment 2. Many findings presented here corroborate results from other PlioMIP multi-model ensemble papers, but we also emphasize features in the ModelE2-R simulations that are unlike the ensemble means. We provide discussion of features that show considerable improvement compared with simulations from previous versions of the NASA GISS models, improvement defined here as simulation results that more closely resemble the ocean core data as well as the PRISM3D reconstructions of the mid-Pliocene climate. In some regions even qualitative agreement between model results and paleodata are an improvement over past studies, but the dramatic warming in the North Atlantic and Greenland-Iceland-Norwegian Sea in these new simulations is by far the most accurate portrayal ever of this key geographic region by the GISS climate model. Our belief is that continued development of key physical routines in the atmospheric model, along with higher resolution and recent corrections to mixing parameterizations in the ocean model, have led to an Earth System Model that will produce more accurate projections of future climate.

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