The Regional Earth System Model RegCM‐ES: Evaluation of the Mediterranean Climate and Marine Biogeochemistry

Tropical-like Mediterranean storms associated with strong winds, low pressure centers and extreme precipitation are called medicanes. These devastating storms threaten the coastal regions and some small islands in the Mediterranean. Recent studies including future climate projections indicate that the intensity of medicanes could increase under the climate change conditions. Therefore it is important to improve a comprehensive understanding of the medicanes and theirs occurrence processes including thermodynamic mechanisms between the atmosphere and the sea. In pursuing these mechanisms, we use reanalysis/observations (ECMWF&#8217;s ERA5 and MyOCEAN etc.) and coupled Regional Earth System Model (RegESM). The RegESM model is run in coupled mode (Regional Climate Model-RegCM4-12km coupled with Regional Ocean Modelling System-ROMS-1/12&#176;, and Wave Model-WAM-0.125&#176;) and uncoupled mode (RegCM4 only-12km) for 1979-2012 period over the Med-CORDEX domain prescribed under the CORDEX framework. Additionally, standalone simulation of RegCM4 has been forced by Era-Interim Reanalysis over the Med-CORDEX domain and the standalone simulation of the wave model (WAM) has been forced by the standalone RegCM4 wind field (12 km horizontal resolution) for the Mediterranean Sea.We analyze the ability of the coupled and uncoupled models to reproduce the characteristics of the observed medicanes and to investigate the role of air-sea interaction in the simulation of key processes that govern medicane occurrences over the study area. In general, the spatial extent and the timing of the observed medicanes better simulated with the coupled model. The reason behind this better replication with the coupled model is the wave model&#8217;s interactive contribution with the roughness length to the surface winds, which allows necessary conditions for medicane formation. Our results also reveals that the recently developed modeling system RegESM incorporates atmosphere, ocean and wave components and thereby is better capable to improve the understanding of the mechanisms driving medicanes.Keywords Regional earth system model, Ocean-atmosphere-wave coupling, MedicanesAcknowledgements This study has been supported by a research grant 40248 by the Scientific Research Projects Coordination Unit of Istanbul Technical University (ITU) and &#160;a research grant (116Y136) provided by The Scientific and Technological Research Council of Turkey (TUBITAK). The computing resources used in this work were provided by the National Center for High Performance Computing of Turkey (UHEM) under grant number 5004782017.

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Review of the manuscript Dynamics of the Mediterranean droughts from 850 to 2099 AD in the Community Earth System Model by Woon Mi Kim and Christoph C. Raible submitted for publication in Climate of the Past

10.5194/cp-2020-79-rc1 ◽

2020 ◽

Author(s):

Anonymous

Keyword(s):

Earth System Model ◽

System Model ◽

Earth System ◽

The Past ◽

Community Earth System Model ◽

The Mediterranean

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Supplementary material to "FOCI-MOPS v1 – Integration of Marine Biogeochemistry within the Flexible Ocean and Climate Infrastructure version 1 (FOCI 1) Earth system model"

10.5194/gmd-2021-361-supplement ◽

2022 ◽

Author(s):

Chia-Te Chien ◽

Jonathan V. Durgadoo ◽

Dana Ehlert ◽

Ivy Frenger ◽

David P. Keller ◽

...

Keyword(s):

Earth System Model ◽

System Model ◽

Earth System ◽

Marine Biogeochemistry ◽

Supplementary Material

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Dynamics of the Mediterranean droughts from 850 to 2099 AD in the Community Earth System Model

10.5194/cp-2020-79 ◽

2020 ◽

Author(s):

Woon Mi Kim ◽

Christoph C. Raible

Keyword(s):

Mediterranean Region ◽

Southern Oscillation ◽

Earth System Model ◽

System Model ◽

Drought Indices ◽

Positive Temperature ◽

Earth System ◽

Modes Of Variability ◽

Community Earth System Model ◽

The Mediterranean

Abstract. In this study, we analyze the dynamics of multi-year long droughts over the western and central Mediterranean region for the period of 850–2099 AD using the Community Earth System model version 1.0.1. Our study indicates that Mediterranean droughts during the period of 850–1849 AD are mainly driven by the internal variability of the climate system. A barotropic high pressure system together with a positive temperature anomaly over central Europe and the Mediterranean is the prominent pattern that occurs in all seasons with droughts. Modes of variability, i.e. the North Atlantic Oscillation and El Niño Southern-Oscillation, play an important role at the initial stage of droughts. However, the persistence of multi-year droughts is determined by the interaction between the regional atmospheric and soil moisture variables. This interaction becomes stronger during the 1850–2099 AD period, reducing the importance of modes of variability and inducing a constant dryness over the Mediterranean region. Additionally, the discrepancy among diverse drought metrics in representing past droughts is shown, re-affirming the necessity of assessing a variety of drought indices even in the paleoclimate context.

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Reviewer Number 2: Review of Dynamics of the Mediterranean droughts from 850 to 2099 AD in the Community Earth System Model

10.5194/cp-2020-79-rc2 ◽

2020 ◽

Author(s):

Anonymous

Keyword(s):

Earth System Model ◽

System Model ◽

Earth System ◽

Community Earth System Model ◽

The Mediterranean

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Dynamics of the Mediterranean droughts from 850 to 2099 CE in the Community Earth System Model

Climate of the Past ◽

10.5194/cp-17-887-2021 ◽

2021 ◽

Vol 17 (2) ◽

pp. 887-911

Author(s):

Woon Mi Kim ◽

Christoph C. Raible

Keyword(s):

Volcanic Eruptions ◽

Earth System Model ◽

System Model ◽

Drought Indices ◽

Positive Temperature ◽

Earth System ◽

Central Mediterranean ◽

Modes Of Variability ◽

Community Earth System Model ◽

The Mediterranean

Abstract. In this study, we analyze the dynamics of multi-year droughts over the western and central Mediterranean for the period of 850–2099 CE using the Community Earth System Model version 1.0.1. Overall, the model is able to realistically represent droughts over this region, although it shows some biases in representing El Niño–Southern Oscillation (ENSO) variability and mesoscale phenomena that are relevant in the context of droughts over the region. The analysis of the simulations shows that there is a discrepancy among diverse drought metrics in representing duration and frequencies of past droughts in the western and central Mediterranean. The self-calibrated Palmer drought severity index identifies droughts with significantly longer duration than other drought indices during 850–1849 CE. This re-affirms the necessity of assessing a variety of drought indices in drought studies in the paleoclimate context as well. Independent of the choice of the drought index, the analysis of the period 850–1849 CE suggests that Mediterranean droughts are mainly driven by internal variability of the climate system rather than external forcing. Strong volcanic eruptions show no connection to dry conditions but instead are connected to wet conditions over the Mediterranean. The analysis further shows that Mediterranean droughts are characterized by a barotropic high-pressure system together with a positive temperature anomaly over central Europe. This pattern occurs in all seasons of drought years, with stronger amplitudes during winter and spring. The North Atlantic Oscillation (NAO) and ENSO are also involved during Mediterranean multi-year droughts, showing that droughts occur more frequently with positive NAO and La Niña-like conditions. These modes of variability play a more important role during the initial stage of droughts. As a result, the persistence of multi-year droughts is determined by the interaction between the regional atmospheric and soil moisture variables, i.e., the land–atmosphere feedbacks, during the transition years of droughts. These feedbacks are intensified during the period 1850–2099 CE due to the anthropogenic influence, thus reducing the role of modes of variability on droughts in this period. Eventually, the land–atmosphere feedbacks induce a constant dryness over the Mediterranean region for the late 21st century relative to the period 1000–1849 CE.

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

10.5194/gmd-2020-248 ◽

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.

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FOCI-MOPS v1 – Integration of Marine Biogeochemistry within the Flexible Ocean and Climate Infrastructure version 1 (FOCI 1) Earth system model

10.5194/gmd-2021-361 ◽

2022 ◽

Author(s):

Chia-Te Chien ◽

Jonathan V. Durgadoo ◽

Dana Ehlert ◽

Ivy Frenger ◽

David P. Keller ◽

...

Keyword(s):

Climate Model ◽

Coupled Model ◽

Surface Air Temperature ◽

Earth System Model ◽

System Model ◽

Biogeochemical Model ◽

Historical Period ◽

Earth System ◽

Marine Biogeochemistry ◽

Ocean Carbon

Abstract. The consideration of marine biogeochemistry is essential for simulating the carbon cycle in an Earth system model. Here we present the implementation and evaluation of a marine biogeochemical model, Model of Oceanic Pelagic Stoichiometry (MOPS) in the Flexible Ocean and Climate Infrastructure (FOCI) climate model. FOCI-MOPS enables the simulation of marine biological processes, the marine carbon, nitrogen and oxygen cycles, air-sea gas exchange of CO2 and O2, and simulations with prescribed atmospheric CO2 or CO2 emissions. A series of experiments covering the historical period (1850–2014) were performed following the DECK (Diagnostic, Evaluation and Characterization of Klima) and CMIP6 (Coupled Model Intercomparison Project 6) protocols. Overall, modelled biogeochemical tracer distributions and fluxes, as well as transient evolution in surface air temperature, air-sea CO2 fluxes, and changes of ocean carbon and heat, are in good agreement with observations. Modelled inorganic and organic tracer distributions are quantitatively evaluated by statistically-derived metrics. Results of the FOCI-MOPS model, also including sea surface temperature, surface pH, oxygen (100–600 m), nitrate (0–100 m), and primary production, are within the range of other CMIP6 model results. Overall, the evaluation of FOCI-MOPS indicates its suitability for Earth climate system simulations.

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