scholarly journals Contrasting juxtaposition of two paradigms for diazotrophy in an Earth System Model of intermediate complexity

2020 ◽  
Author(s):  
Ulrike Löptien ◽  
Heiner Dietze
Keyword(s):  
Nitrogen Fixation ◽  
Ecological Niche ◽  
Earth System Model ◽  
System Model ◽  
Earth System ◽  
Nitrogen Fixers ◽  
Model Configuration ◽  
Rcp 8.5 ◽  
Similar Good ◽  
Inorganic Phosphorous

Abstract. Nitrogen fixers, or diazotrophs, play a key role in the carbon and nitrogen cycle of the world oceans, but the controlling mechanisms are not comprehensively understood yet. The present study compares two paradigms on the ecological niche of diazotrophs in an Earth System Model (ESM). In our standard model configuration, which is representative for most of the state-of-the-art pelagic ecosystem models, diazotrophs take advantage of zooplankton featuring a lower food preference for diazotrophs than for ordinary phytoplankton. We compare this paradigm with the idea that diazotrophs are more competitive under oligotrophic conditions, characterized by low (dissolved, particulate, organic and inorganic) phosphorous availability. Both paradigms are supported by observational evidence and lead to a similar good agreement to the most recent and advanced observation-based nitrogen fixation estimate in our ESM framework. Further, we illustrate that the similarity between the two paradigms breaks in a RCP 8.5 anthropogenic emission scenario. We conclude that a more advanced understanding of the ecological niche of diazotrophs is mandatory for assessing the cycling of essential nutrients, especially under changing environmental conditions. Our results call for more in-situ measurements of cyanobacteria biomass if major controls of nitrogen fixation in the oceans are to be dissected.

scholarly journals Empirical and Earth system model estimates of boreal nitrogen fixation often differ: a pathway toward reconciliation

2021 ◽  
Author(s):  
Stefan F. Hupperts ◽  
Stefan Gerber ◽  
Marie‐Charlotte Nilsson ◽  
Michael J. Gundale
Keyword(s):  
Nitrogen Fixation ◽  
Earth System Model ◽  
System Model ◽  
Earth System

scholarly journals Avaliação dos Impactos das Mudanças na Cobertura da Terra e Cenário de Emissões (RCP 8.5) no Balanço de água na Bacia do Rio Madeira

2020 ◽  
Vol 35 (4) ◽  
pp. 689-702
Author(s):  
Weslley de Brito Gomes ◽  
Francis Wagner Silva Correia ◽  
Vinicius Capistrano ◽  
José Augusto Paixão Veiga ◽  
Leonardo Alves Vergasta ◽  
...  
Keyword(s):  
Earth System Model ◽  
System Model ◽  
Earth System ◽  
Ocean Atmosphere ◽  
Rcp 8.5 ◽  
Model Ocean ◽  
Rio Madeira

Resumo Nesse estudo avaliou-se os impactos do aumento dos GEE's (cenário RCP 8.5) e dos desflorestamentos no ciclo da água na bacia do rio Madeira, utilizando o Modelo Regional Eta e o Modelo Hidrológico de Grandes Bacias (MGB), forçado com o Brazilian Earth System Model Ocean-Atmosphere versão 2.5 (BESM-OA 2.5). No cenário RCP 8.5, o modelo apresentou sensibilidade sobre toda a bacia do Madeira, com aumento da ordem de 4.0 °C na temperatura. O aumento foi intensificado com os cenários de desflorestamentos de 2050 (4.8 °C) e 2100 (6.2 °C). Nos cenários de desflorestamento predominou-se o Mecanismo de Retroalimentação Negativo, pois embora haja reduções na precipitação e evapotranspiração, a convergência de umidade aumentou em todos os cenários. Observou-se aumento das descargas na maioria das estações para todos os cenários futuros RCP 8.5 e desflorestamento. O aumento da precipitação na estação seca explicou em parte o aumento das vazões e na área de inundação sobre a bacia do Madeira. O aumento na precipitação à montante da bacia e a mudança nos parâmetros do solo, associada às alterações no uso da terra, contribuíram para o aumento da vazão e área de inundação sobre a bacia do Madeira. As alterações nas descargas e na área de inundação podem ter efeitos negativos, com prejuízos e danos ao meio ambiente, nos recursos hídricos, nos principais setores da economia, afetando de forma direta as comunidades que vivem às margens dos rios, principalmente as populações vulneráveis da bacia do Madeira.

Korea Institute of Ocean Science and Technology Earth System Model and Its Simulation Characteristics

2021 ◽  
Author(s):  
Gyundo Pak ◽  
Yign Noh ◽  
Myong-In Lee ◽  
Sang-Wook Yeh ◽  
Daehyun Kim ◽  
...  
Keyword(s):  
Science And Technology ◽  
Earth System Model ◽  
System Model ◽  
Earth System ◽  
Ocean Science

scholarly journals Climate Change Projection in the Twenty-First Century Simulated by NIMS-KMA CMIP6 Model Based on New GHGs Concentration Pathways

2021 ◽  
Author(s):  
Hyun Min Sung ◽  
Jisun Kim ◽  
Sungbo Shim ◽  
Jeong-byn Seo ◽  
Sang-Hoon Kwon ◽  
...  
Keyword(s):  
Climate Change ◽  
Climate Changes ◽  
Scientific Information ◽  
Earth System Model ◽  
First Century ◽  
System Model ◽  
The Arctic ◽  
Earth System ◽  
Future Projections ◽  
Twenty First Century

AbstractThe National Institute of Meteorological Sciences-Korea Meteorological Administration (NIMS-KMA) has participated in the Coupled Model Inter-comparison Project (CMIP) and provided long-term simulations using the coupled climate model. The NIMS-KMA produces new future projections using the ensemble mean of KMA Advanced Community Earth system model (K-ACE) and UK Earth System Model version1 (UKESM1) simulations to provide scientific information of future climate changes. In this study, we analyze four experiments those conducted following the new shared socioeconomic pathway (SSP) based scenarios to examine projected climate change in the twenty-first century. Present day (PD) simulations show high performance skill in both climate mean and variability, which provide a reliability of the climate models and reduces the uncertainty in response to future forcing. In future projections, global temperature increases from 1.92 °C to 5.20 °C relative to the PD level (1995–2014). Global mean precipitation increases from 5.1% to 10.1% and sea ice extent decreases from 19% to 62% in the Arctic and from 18% to 54% in the Antarctic. In addition, climate changes are accelerating toward the late twenty-first century. Our CMIP6 simulations are released to the public through the Earth System Grid Federation (ESGF) international data sharing portal and are used to support the establishment of the national adaptation plan for climate change in South Korea.

scholarly journals Quantifying the Cloud Particle‐Size Feedback in an Earth System Model

2019 ◽  
Vol 46 (19) ◽  
pp. 10910-10917
Author(s):  
Jiang Zhu ◽  
Christopher J. Poulsen
Keyword(s):  
Particle Size ◽  
Earth System Model ◽  
System Model ◽  
Earth System ◽  
Cloud Particle

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.

Sign in / Sign up

Export Citation Format

Share Document