scholarly journals Marine biogeochemical cycling and climate-carbon cycle feedback simulated by the NUIST Earth System Model: NESM-2.0.1

2018 ◽  
Author(s):  
Yifei Dai ◽  
Long Cao ◽  
Bin Wang
Keyword(s):  
Climate Change ◽  
Carbon Cycle ◽  
Earth System Model ◽  
Atmospheric Co2 ◽  
System Model ◽  
Co2 Uptake ◽  
Earth System ◽  
Feedback Parameter ◽  
Model Simulations ◽  
Ocean Carbon

Abstract. In this study, we evaluate the performance of Nanjing University of Information Science & Technology Earth System Model, version 2.0.1 (hereafter NESM-2.0.1). We focus on model simulated historical and future oceanic CO2 uptake, and analyze the effect of global warming on model-simulated oceanic CO2 uptake. Compared with available observations and data-based estimates, NESM-2.0.1 reproduces reasonably well large-scale ocean carbon-related fields, including nutrients (phosphate, nitrite and silicate), chlorophyll, and net primary production. However, some noticeable discrepancies between model simulations and observations are found in the deep ocean and coastal regions. Model-simulated current-day oceanic CO2 uptake compares well with data-based estimate. From pre-industrial time to 2011, modeled cumulative CO2 uptake is 144 PgC, compared with data-based estimates of 155 ± 30 PgC. Diagnosed from the end of the benchmark 1 % per year CO2 increase simulations, carbon-climate feedback parameter, which represents the sensitivity of ocean CO2 uptake to climate change, is −7.1 PgC/K; Carbon-concentration feedback parameter, which represents the sensitivity of ocean CO2 uptake to increase in atmospheric CO2 is 0.81 PgC/ppm. These two feedback parameters diagnosed from model simulations are consistent with the mean value diagnosed from the CMIP5 (Coupled Model Intercomparison Project phase 5) model simulations under the same 1 % per year CO2 simulations (−7.8 PgC/K and 0.80 PgC/ppm, respectively). Our results demonstrate that NESM-2.0.1 can be used as a useful tool in the investigation of feedback interactions between the ocean carbon cycle, atmospheric CO2, and climate change.

scholarly journals Bergen Earth system model (BCM-C): model description and regional climate-carbon cycle feedbacks assessment

2010 ◽  
Vol 3 (1) ◽  
pp. 123-141 ◽  
Author(s):  
J. F. Tjiputra ◽  
K. Assmann ◽  
M. Bentsen ◽  
I. Bethke ◽  
O. H. Otterå ◽  
...  
Keyword(s):  
Climate Change ◽  
Carbon Cycle ◽  
Regional Climate ◽  
Earth System Model ◽  
System Model ◽  
Model Description ◽  
Earth System ◽  
Carbon Cycle Model ◽  
Enhanced Production ◽  
Positive Climate

Abstract. We developed a complex Earth system model by coupling terrestrial and oceanic carbon cycle components into the Bergen Climate Model. For this study, we have generated two model simulations (one with climate change inclusions and the other without) to study the large scale climate and carbon cycle variability as well as its feedback for the period 1850–2100. The simulations are performed based on historical and future IPCC CO2 emission scenarios. Globally, a pronounced positive climate-carbon cycle feedback is simulated by the terrestrial carbon cycle model, but smaller signals are shown by the oceanic counterpart. Over land, the regional climate-carbon cycle feedback is highlighted by increased soil respiration, which exceeds the enhanced production due to the atmospheric CO2 fertilization effect, in the equatorial and northern hemisphere mid-latitude regions. For the ocean, our analysis indicates that there are substantial temporal and spatial variations in climate impact on the air-sea CO2 fluxes. This implies feedback mechanisms act inhomogeneously in different ocean regions. In the North Atlantic subpolar gyre, the simulated future cooling of SST improves the CO2 gas solubility in seawater and, hence, reduces the strength of positive climate carbon cycle feedback in this region. In most ocean regions, the changes in the Revelle factor is dominated by changes in surface pCO2, and not by the warming of SST. Therefore, the solubility-associated positive feedback is more prominent than the buffer capacity feedback. In our climate change simulation, the retreat of Southern Ocean sea ice due to melting allows an additional ~20 Pg C uptake as compared to the simulation without climate change.

scholarly journals Hackathon Speeds Progress Toward Climate Model Collaboration

Eos ◽  
2019 ◽  
Vol 100 ◽  
Author(s):  
Wilbert Weijer ◽  
Forrest Hoffman ◽  
Paul Ullrich ◽  
Michael Wehner ◽  
Jialin Liu
Keyword(s):  
Climate Change ◽  
Climate Model ◽  
Earth System Model ◽  
System Model ◽  
Earth System ◽  
Model Simulations

Climate scientists collaborated in a nationwide event to analyze and compare archived Earth system model simulations and to generate input for the IPCC's upcoming climate change report.

scholarly journals Evaluation of NorESM-OC (versions 1 and 1.2), the ocean carbon-cycle stand-alone configuration of the Norwegian Earth System Model (NorESM1)

2016 ◽  
Author(s):  
J. Schwinger ◽  
N. Goris ◽  
J. Tjiputra ◽  
I. Kriest ◽  
M. Bentsen ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Deep Ocean ◽  
Earth System Model ◽  
System Model ◽  
Earth System ◽  
Atmospheric Forcing ◽  
Ocean Carbon Cycle ◽  
Data Set ◽  
Model Version ◽  
Ocean Carbon

Abstract. Idealised and hindcast simulations performed with the stand-alone ocean carbon-cycle configuration of the Norwegian Earth System Model (NorESM-OC) are described and evaluated. We present simulation results of two different model versions at different grid resolutions and using two different atmospheric forcing data sets. Model version NorESM-OC1 corresponds to the version that is included in the fully coupled model NorESM-ME1, which participated in CMIP5. The main update between NorESM-OC1 and NorESM-OC1.2 is the addition of two new options for the treatment of sinking particles. We find that using a constant sinking speed, which has been the standard in NorESM's ocean carbon cycle module HAMOCC (HAMburg Ocean Carbon Cycle model) does not transport enough particulate organic carbon (POC) into the deep ocean below approximately 2000 m depth. The two newly implemented parameterisations, a particle aggregation scheme with prognostic sinking speed, and a simpler scheme prescribing a linear increase of sinking speed with depth, provide better agreement with observed POC fluxes. Additionally, reduced deep ocean biases of oxygen and remineralised phosphate indicate a better performance of the new parameterisations. For model version 1.2, a re-tuning of the ecosystem parameterisation has been performed, which (i) reduces previously too high primary production in high latitudes, (ii) consequently improves model results for surface nutrients, and (iii) reduces alkalinity and dissolved inorganic carbon biases at low latitudes. We use hindcast simulations with prescribed observed and constant (pre-industrial) atmospheric CO2 concentrations to derive the past and contemporary ocean carbon sink. For the period 1990–1999 we find an average ocean carbon uptake ranging from 2.01 to 2.58 Pg C yr-1 depending on model version, grid resolution and atmospheric forcing data set.

scholarly journals Marine geochemical data assimilation in an efficient Earth System Model of global biogeochemical cycling

2007 ◽  
Vol 4 (1) ◽  
pp. 87-104 ◽  
Author(s):  
A. Ridgwell ◽  
J. C. Hargreaves ◽  
N. R. Edwards ◽  
J. D. Annan ◽  
T. M. Lenton ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Biogeochemical Cycling ◽  
Earth System Model ◽  
Atmospheric Co2 ◽  
System Model ◽  
Geochemical Data ◽  
Model Parameters ◽  
Earth System ◽  
Export Production ◽  
Ocean Carbon

Abstract. We have extended the 3-D ocean based "Grid ENabled Integrated Earth system model" (GENIE-1) to help understand the role of ocean biogeochemistry and marine sediments in the long-term (~100 to 100 000 year) regulation of atmospheric CO2, and the importance of feedbacks between CO2 and climate. Here we describe the ocean carbon cycle, which in its first incarnation is based around a simple single nutrient (phosphate) control on biological productivity. The addition of calcium carbonate preservation in deep-sea sediments and its role in regulating atmospheric CO2 is presented elsewhere (Ridgwell and Hargreaves, 2007). We have calibrated the model parameters controlling ocean carbon cycling in GENIE-1 by assimilating 3-D observational datasets of phosphate and alkalinity using an ensemble Kalman filter method. The calibrated (mean) model predicts a global export production of particulate organic carbon (POC) of 8.9 PgC yr−1, and reproduces the main features of dissolved oxygen distributions in the ocean. For estimating biogenic calcium carbonate (CaCO3) production, we have devised a parameterization in which the CaCO3:POC export ratio is related directly to ambient saturation state. Calibrated global CaCO3 export production (1.2 PgC yr-1) is close to recent marine carbonate budget estimates. The GENIE-1 Earth system model is capable of simulating a wide variety of dissolved and isotopic species of relevance to the study of modern global biogeochemical cycles as well as past global environmental changes recorded in paleoceanographic proxies. Importantly, even with 12 active biogeochemical tracers in the ocean and including the calculation of feedbacks between atmospheric CO2 and climate, we achieve better than 1000 years per (2.4 GHz) CPU hour on a desktop PC. The GENIE-1 model thus provides a viable alternative to box and zonally-averaged models for studying global biogeochemical cycling over all but the very longest (>1 000 000 year) time-scales.

Characterizing post-industrial changes in the ocean carbon cycle in an Earth system model

Tellus B ◽  
2010 ◽  
Vol 62 (4) ◽  
pp. 296-313 ◽  
Author(s):  
Katsumi Matsumoto ◽  
Kathy Tokos ◽  
Megumi Chikamoto ◽  
Andy Ridgwell
Keyword(s):  
Carbon Cycle ◽  
Earth System Model ◽  
System Model ◽  
Earth System ◽  
Ocean Carbon Cycle ◽  
Ocean Carbon ◽  
Post Industrial

scholarly journals Development and evaluation of CNRM Earth system model – CNRM-ESM1

2016 ◽  
Vol 9 (4) ◽  
pp. 1423-1453 ◽  
Author(s):  
Roland Séférian ◽  
Christine Delire ◽  
Bertrand Decharme ◽  
Aurore Voldoire ◽  
David Salas y Melia ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Sea Ice ◽  
Ecosystem Respiration ◽  
World Ocean ◽  
Earth System Model ◽  
System Model ◽  
Shortwave Radiation ◽  
Climate Simulation ◽  
Co2 Uptake ◽  
Earth System

Abstract. We document the first version of the Centre National de Recherches Météorologiques Earth system model (CNRM-ESM1). This model is based on the physical core of the CNRM climate model version 5 (CNRM-CM5) model and employs the Interactions between Soil, Biosphere and Atmosphere (ISBA) and the Pelagic Interaction Scheme for Carbon and Ecosystem Studies (PISCES) as terrestrial and oceanic components of the global carbon cycle. We describe a preindustrial and 20th century climate simulation following the CMIP5 protocol. We detail how the various carbon reservoirs were initialized and analyze the behavior of the carbon cycle and its prominent physical drivers. Over the 1986–2005 period, CNRM-ESM1 reproduces satisfactorily several aspects of the modern carbon cycle. On land, the model captures the carbon cycling through vegetation and soil, resulting in a net terrestrial carbon sink of 2.2 Pg C year−1. In the ocean, the large-scale distribution of hydrodynamical and biogeochemical tracers agrees with a modern climatology from the World Ocean Atlas. The combination of biological and physical processes induces a net CO2 uptake of 1.7 Pg C year−1 that falls within the range of recent estimates. Our analysis shows that the atmospheric climate of CNRM-ESM1 compares well with that of CNRM-CM5. Biases in precipitation and shortwave radiation over the tropics generate errors in gross primary productivity and ecosystem respiration. Compared to CNRM-CM5, the revised ocean–sea ice coupling has modified the sea-ice cover and ocean ventilation, unrealistically strengthening the flow of North Atlantic deep water (26.1 ± 2 Sv). It results in an accumulation of anthropogenic carbon in the deep ocean.

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