scholarly journals JULES-GL7: the Global Land configuration of the Joint UK Land Environment Simulator version 7.0 and 7.2

2020 ◽  
Vol 13 (2) ◽  
pp. 483-505 ◽  
Author(s):  
Andrew J. Wiltshire ◽  
Maria Carolina Duran Rojas ◽  
John M. Edwards ◽  
Nicola Gedney ◽  
Anna B. Harper ◽  
...  
Keyword(s):  
Land Surface ◽  
Coupled Model ◽  
Ancillary Data ◽  
Natural Environment Research Council ◽  
Code Base ◽  
Global Land ◽  
Standard Configuration ◽  
Intercomparison Project ◽  
Land Surface Modelling ◽  
Parameter Values

Abstract. We present the latest global land configuration of the Joint UK Land Environment Simulator (JULES) model as used in the latest international Coupled Model Intercomparison Project (CMIP6). The configuration is defined by the combination of switches, parameter values and ancillary data, which we provide alongside a set of historical forcing data that defines the experimental setup. The configurations provided are JULES-GL7.0, the base setup used in CMIP6 and JULES-GL7.2, a subversion that includes improvements to the representation of canopy radiation and interception. These configurations are recommended for all JULES applications focused on the exchange and state of heat, water and momentum at the land surface. In addition, we provide a standardised modelling system that runs on the Natural Environment Research Council (NERC) JASMIN cluster, accessible to all JULES users. This is provided so that users can test and evaluate their own science against the standard configuration to promote community engagement in the development of land surface modelling capability through JULES. It is intended that JULES configurations should be independent of the underlying code base, and thus they will be available in the latest release of the JULES code. This means that different code releases will produce scientifically comparable results for a given configuration version. Versioning is therefore determined by the configuration as opposed to the underlying code base.

scholarly journals JULES-GL7: The Global Land Configuration of the Joint UK Land Environment Simulation version 7.0

2019 ◽  
Author(s):  
Andrew J. Wiltshire ◽  
Carolina Duran Rojas ◽  
John Edwards ◽  
Nicola Gedney ◽  
Anna B. Harper ◽  
...  
Keyword(s):  
Land Surface ◽  
Coupled Model ◽  
Ancillary Data ◽  
Code Base ◽  
Global Land ◽  
Standard Configuration ◽  
Environment Simulation ◽  
Intercomparison Project ◽  
Land Surface Modelling ◽  
Parameter Values

Abstract. We present the latest global land configuration of the Joint UK Land Environment Simulator (JULES) model as used in the latest international coupled model intercomparison project (CMIP6). The configuration is defined by the combination of switches, parameter values and ancillary data, which we provide alongside a set of historical forcing data that defines the experimental setup. In addition, we provide a standardised modelling system that runs on the NERC JASMIN cluster accessible to all with links to JULES. This is provided so that users can test and evaluate their own science against the standard configuration to promote community engagement in the development of land surface modelling capability through JULES. It is intended that JULES configurations should be independent of the underlying code base and thus they will be available at the latest release of the JULES code. This means that different code releases will produce scientifically comparable results for a given configuration version. Versioning is therefore determined by the configuration as opposed to the underlying code base.

scholarly journals Benchmarking and Process Diagnostics of Land Models

2018 ◽  
Vol 19 (11) ◽  
pp. 1835-1852 ◽  
Author(s):  
Grey S. Nearing ◽  
Benjamin L. Ruddell ◽  
Martyn P. Clark ◽  
Bart Nijssen ◽  
Christa Peters-Lidard
Keyword(s):  
Land Surface ◽  
Model Performance ◽  
Land Surface Model ◽  
Surface Model ◽  
Process Diagnostics ◽  
Surface Energy Fluxes ◽  
Structural Error ◽  
Intercomparison Project ◽  
Parameter Values ◽  
Process Level

Abstract We propose a conceptual and theoretical foundation for information-based model benchmarking and process diagnostics that provides diagnostic insight into model performance and model realism. We benchmark against a bounded estimate of the information contained in model inputs to obtain a bounded estimate of information lost due to model error, and we perform process-level diagnostics by taking differences between modeled versus observed transfer entropy networks. We use this methodology to reanalyze the recent Protocol for the Analysis of Land Surface Models (PALS) Land Surface Model Benchmarking Evaluation Project (PLUMBER) land model intercomparison project that includes the following models: CABLE, CH-TESSEL, COLA-SSiB, ISBA-SURFEX, JULES, Mosaic, Noah, and ORCHIDEE. We report that these models (i) use only roughly half of the information available from meteorological inputs about observed surface energy fluxes, (ii) do not use all information from meteorological inputs about long-term Budyko-type water balances, (iii) do not capture spatial heterogeneities in surface processes, and (iv) all suffer from similar patterns of process-level structural error. Because the PLUMBER intercomparison project did not report model parameter values, it is impossible to know whether process-level error patterns are due to model structural error or parameter error, although our proposed information-theoretic methodology could distinguish between these two issues if parameter values were reported. We conclude that there is room for significant improvement to the current generation of land models and their parameters. We also suggest two simple guidelines to make future community-wide model evaluation and intercomparison experiments more informative.

Challenges in Constraining Future Change of Global Land Precipitation in CMIP6 Models

2020 ◽  
Author(s):  
June-Yi Lee ◽  
Kyung-Sook Yun ◽  
Arjun Babu ◽  
Young-Min Yang ◽  
Eui-Seok Chung ◽  
...  
Keyword(s):  
Global Warming ◽  
Emission Scenario ◽  
Coupled Model ◽  
Precipitation Change ◽  
Cmip5 Models ◽  
Model Intercomparison ◽  
Projected Change ◽  
Global Land ◽  
Intercomparison Project ◽  
Global Mean

<p><span>The Coupled Model Intercomparison Project Phase 5 (CMIP5) models have showed substantial inter-model spread in estimating annual global-mean precipitation change per one-degree greenhouse-gas-induced warming (precipitation sensitivity), ranging from -4.5</span><span>–4.2</span><span>%</span><sup><span>o</span></sup><span>C<sup>-1</sup>in the Representative Concentration Pathway (RCP) 2.6, the lowest emission scenario, to 0.2–4.0</span><span>%</span><sup><span>o</span></sup><span>C<sup>-1</sup>in the RCP 8.5, the highest emission scenario. The observed-based estimations in the global-mean land precipitation sensitivity during last few decades even show much larger spread due to the considerable natural interdecadal variability, role of anthropogenic aerosol forcing, and uncertainties in observation. This study tackles to better quantify and constrain global land precipitation change in response to global warming by analyzing the new range of Shared Socio-economic Pathway (SSP) scenarios in the </span><span>Coupled Model Intercomparison Project Phase 6 (CMIP6) compared with RCP scenarios in the CMIP5. We show that the range of projected change in annual global-mean land (ocean) precipitation by the end of the 21<sup>st</sup>century relative to the recent past (1995-2014) in the 23 CMIP6 models is over 50% (20%) larger than that in corresponding scenarios of the 40 CMIP5 models. The estimated ranges of precipitation sensitivity in four Tier-1 SSPs are also larger than those in corresponding CMIP5 RCPs. The large increase in projected precipitation change in the highest quartile over ocean is mainly due to the increased number of high equilibrium climate sensitivity (ECS) models in CMIP6 compared to CMIP5, but not over land due to different response of thermodynamic moisture convergence and dynamic processes to global warming. We further discuss key challenges in constraining future precipitation change and source of uncertainties in land precipitation change.</span></p>

scholarly journals Hydroclimatic variability and change in the Chesapeake Bay Watershed

2016 ◽  
Vol 8 (2) ◽  
pp. 254-273 ◽  
Author(s):  
Chounghyun Seong ◽  
Venkataramana Sridhar
Keyword(s):  
Chesapeake Bay ◽  
Land Surface ◽  
Daily Precipitation ◽  
Coupled Model ◽  
Baseline Period ◽  
Northern Region ◽  
Chesapeake Bay Watershed ◽  
Intercomparison Project ◽  
Hydroclimatic Variability ◽  
High Degree

The Chesapeake Bay (CB) Watershed is undergoing changes in climate, hydrology, and land use. The assessment of hydroclimatic impacts is important for both water quantity and quality management. This study evaluated the hydroclimatic changes using the Coupled Model Intercomparison Project 5 (CMIP5) data which provided statistically downscaled daily precipitation and temperature. An increase of 3.0 to 5.2 °C in temperature was projected between 2070 and 2099 when compared with the baseline period of 1970–1999. However, precipitation projections showed a modest increase with an average of 5.2 and 8.4% between 2070 and 2099. The northern part of the CB Watershed was expected to be wetter and warmer than the southern region. The average changes in flow were projected between −12 and 6% and −22 to 5% between 2070 and 2099, respectively, under two scenarios. Minimum changes in winter and highest flow reduction in fall with a high degree of variability among the ensemble members was expected. Greater decrease in flows in the northern region of the CB Watershed was projected. Despite the wetter future projections at the end of the century and uncertainties in our evapotranspiration (ET) estimation, reductions in the land surface runoff partly were attributed to increased ET.

scholarly journals Intermodel Variability and Mechanism Attribution of Central and Southeastern U.S. Anomalous Cooling in the Twentieth Century as Simulated by CMIP5 Models

2013 ◽  
Vol 26 (17) ◽  
pp. 6215-6237 ◽  
Author(s):  
Zaitao Pan ◽  
Xiaodong Liu ◽  
Sanjiv Kumar ◽  
Zhiqiu Gao ◽  
James Kinter
Keyword(s):  
United States ◽  
Twentieth Century ◽  
Land Surface ◽  
Regional Scale ◽  
Coupled Model ◽  
The United States ◽  
Cmip5 Models ◽  
Model Intercomparison ◽  
Central United States ◽  
Intercomparison Project

Abstract Some parts of the United States, especially the southeastern and central portion, cooled by up to 2°C during the twentieth century, while the global mean temperature rose by 0.6°C (0.76°C from 1901 to 2006). Studies have suggested that the Pacific decadal oscillation (PDO) and the Atlantic multidecadal oscillation (AMO) may be responsible for this cooling, termed the “warming hole” (WH), while other works reported that regional-scale processes such as the low-level jet and evapotranspiration contribute to the abnormity. In phase 3 of the Coupled Model Intercomparison Project (CMIP3), only a few of the 53 simulations could reproduce the cooling. This study analyzes newly available simulations in experiments from phase 5 of the Coupled Model Intercomparison Project (CMIP5) from 28 models, totaling 175 ensemble members. It was found that 1) only 19 out of 100 all-forcing historical ensemble members simulated negative temperature trend (cooling) over the southeast United States, with 99 members underpredicting the cooling rate in the region; 2) the missing of cooling in the models is likely due to the poor performance in simulating the spatial pattern of the cooling rather than the temporal variation, as indicated by a larger temporal correlation coefficient than spatial one between the observation and simulations; 3) the simulations with greenhouse gas (GHG) forcing only produced strong warming in the central United States that may have compensated the cooling; and 4) the all-forcing historical experiment compared with the natural-forcing-only experiment showed a well-defined WH in the central United States, suggesting that land surface processes, among others, could have contributed to the cooling in the twentieth century.

A biophysical process-based estimate of global land surface evaporation using satellite and ancillary data II. Regional and global patterns of seasonal and annual variations

1998 ◽  
Vol 205 (3-4) ◽  
pp. 186-204 ◽  
Author(s):  
Bhaskar J. Choudhury ◽  
Nicolo E. DiGirolamo ◽  
Joel Susskind ◽  
Wayne L. Darnell ◽  
Shashi K. Gupta ◽  
...  
Keyword(s):  
Land Surface ◽  
Ancillary Data ◽  
Surface Evaporation ◽  
Annual Variations ◽  
Global Land ◽  
Biophysical Process ◽  
Global Patterns

scholarly journals MIROC-ESM 2010: model description and basic results of CMIP5-20c3m experiments

2011 ◽  
Vol 4 (4) ◽  
pp. 845-872 ◽  
Author(s):  
S. Watanabe ◽  
T. Hajima ◽  
K. Sudo ◽  
T. Nagashima ◽  
T. Takemura ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Land Surface ◽  
Coupled Model ◽  
Model Description ◽  
Historical Simulation ◽  
Air Temperatures ◽  
Marine Biogeochemistry ◽  
Intercomparison Project ◽  
Transient Variations ◽  
Column Ozone

Abstract. An earth system model (MIROC-ESM 2010) is fully described in terms of each model component and their interactions. Results for the CMIP5 (Coupled Model Intercomparison Project phase 5) historical simulation are presented to demonstrate the model's performance from several perspectives: atmosphere, ocean, sea-ice, land-surface, ocean and terrestrial biogeochemistry, and atmospheric chemistry and aerosols. An atmospheric chemistry coupled version of MIROC-ESM (MIROC-ESM-CHEM 2010) reasonably reproduces transient variations in surface air temperatures for the period 1850–2005, as well as the present-day climatology for the zonal-mean zonal winds and temperatures from the surface to the mesosphere. The historical evolution and global distribution of column ozone and the amount of tropospheric aerosols are reasonably simulated in the model based on the Representative Concentration Pathways' (RCP) historical emissions of these precursors. The simulated distributions of the terrestrial and marine biogeochemistry parameters agree with recent observations, which is encouraging to use the model for future global change projections.

scholarly journals Accelerated hydrological cycle over the Sanjiangyuan region induces more streamflow extremes at different global warming levels

2020 ◽  
Author(s):  
Peng Ji ◽  
Xing Yuan ◽  
Feng Ma ◽  
Ming Pan
Keyword(s):  
Global Warming ◽  
Land Surface ◽  
Yangtze River ◽  
Climate Models ◽  
Hydrological Cycle ◽  
Yellow River ◽  
Coupled Model ◽  
Ecological Processes ◽  
Intercomparison Project ◽  
Streamflow Extremes

Abstract. Serving source water for the Yellow, Yangtze and Lancang-Mekong rivers, the Sanjiangyuan region concerns ~ 700 million people over its downstream areas. Recent research suggests that the Sanjiangyuan region will become wetter in a warming future, but future changes in streamflow extremes remain unclear due to the complex hydrological processes over high-land areas and limited knowledge of the influences of land cover change and CO2 physiological forcing. Based on high resolution land surface modeling during 1979~2100 driven by the climate and ecological projections from 11 newly released Coupled Model Intercomparison Project Phase 6 (CMIP6) climate models, we show that different accelerating rates of precipitation and evapotranspiration at 1.5 °C global warming level induce 55 % more dry extremes over Yellow river and 138 % more wet extremes over Yangtze river headwaters compared with the reference period (1985~2014). An additional 0.5 °C warming leads to a further nonlinear and more significant increase for both dry extremes over Yellow river (22 %) and wet extremes over Yangtze river (64 %). The combined role of CO2 physiological forcing and vegetation greening, which used to be neglected in hydrological projections, is found to alleviate dry extremes at 1.5 and 2.0 °C warming levels but to intensify dry extremes at 3.0 °C warming level. Moreover, vegetation greening contributes half of the differences between 1.5 and 3.0 °C warming levels. This study emphasizes the importance of ecological processes in determining future changes in streamflow extremes, and suggests a dry gets drier, wet gets wetter condition over headwaters.

Role of cloud feedback in continental warming response to CO2 physiological forcing

2021 ◽  
pp. 1-49
Author(s):  
So-Won Park ◽  
Jong-Seong Kug ◽  
Sang-Yoon Jun ◽  
Su-Jong Jeong ◽  
Jin-Soo Kim
Keyword(s):  
Land Surface ◽  
Atmospheric Carbon Dioxide ◽  
Stomatal Closure ◽  
Coupled Model ◽  
Cloud Feedback ◽  
Climate Feedback ◽  
Primary Role ◽  
Surface Warming ◽  
Surface Energy Fluxes ◽  
Intercomparison Project

AbstractStomatal closure is a major physiological response to the increasing atmospheric carbon dioxide (CO2), which can lead to surface warming by regulating surface energy fluxes—a phenomenon known as CO2 physiological forcing. The magnitude of land surface warming caused by physiological forcing is substantial and varies across models. Here we assess the continental warming response to CO2 physiological forcing and quantify the resultant climate feedback using carbon–climate simulations from phases 5 and 6 of the Coupled Model Intercomparison Project, with a focus on identifying the cause of inter-model spread. It is demonstrated that the continental (40°–70°N) warming response to the physiological forcing in summer (~0.55 K) is amplified primarily due to cloud feedback (~1.05 K), whereas the other climate feedbacks, ranged from –0.57 K to 0.20 K, show relatively minor contributions. In addition, the strength of cloud feedback varies considerably across models, which plays a primary role in leading large diversity of the continental warming response to the physiological forcing.

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