scholarly journals La représentation des surfaces continentales dans la modélisation du climat à Météo-France

2020 ◽  
pp. 067
Author(s):  
Bertrand Decharme ◽  
Christine Delire ◽  
Aaron Boone
Keyword(s):  
Land Surface ◽  
Climate Models ◽  
Land Surface Model ◽  
Global Scale ◽  
Surface Model ◽  
Climate Modelling ◽  
History Of ◽  
International Climate ◽  
Land Surfaces ◽  
Computational Resources

Les surfaces continentales jouent un rôle non négligeable dans le système climatique de la Terre. Elles occupent d'ailleurs une place majeure dans les cycles globaux de l'eau et du carbone. Elles ont été prises en compte dès les premiers modèles numériques de climat et, avec l'évolution des connaissances, des capacités de calcul et de la demande sociétale, leur représentation s'est aujourd'hui considérablement complexifiée. Nous présentons ici une brève histoire de l'évolution du modèle de surfaces Isba (Interactions sol-biosphère-atmosphère) de Météo-France dans son utilisation à l'échelle du globe en la replaçant dans le contexte international de la modélisation climatique. Land surfaces play a significant role in the Earth climate system, and they are a major component of the global carbon and water cycles. The first numerical climate models took them into account in very simple ways. Through time the complexity of their representation has increased a lot owing to improved knowledge, larger computational resources and changing societal demands. We present here a brief history of the ISBA (Interactions Soil-Biosphere-Atmosphere) land surface model developed at Météo-France when used at the global scale and how it evolved in the context of international climate modelling.

scholarly journals Integration of nitrogen dynamics into the Noah-MP land model v1.1 for climate and environmental predictions

2015 ◽  
Vol 8 (5) ◽  
pp. 4113-4153 ◽  
Author(s):  
X. Cai ◽  
Z.-L. Yang ◽  
J. B. Fisher ◽  
X. Zhang ◽  
M. Barlage ◽  
...  
Keyword(s):  
Land Surface ◽  
Climate Models ◽  
Net Primary Productivity ◽  
Assessment Tool ◽  
Land Surface Model ◽  
Coupled Model ◽  
Nitrogen Dynamics ◽  
Surface Model ◽  
Meteorological Model ◽  
Environmental Models

Abstract. Climate and terrestrial biosphere models consider nitrogen an important factor in limiting plant carbon uptake, while operational environmental models view nitrogen as the leading pollutant causing eutrophication in water bodies. The community Noah land surface model with multi-parameterization options (Noah-MP) is unique in that it is the next generation land surface model for the Weather Research and Forecasting meteorological model and for the operational weather/climate models in the National Centers for Environmental Prediction. In this study, we add capability to Noah-MP to simulate nitrogen dynamics by coupling the Fixation and Uptake of Nitrogen (FUN) plant model and the Soil and Water Assessment Tool (SWAT) soil nitrogen dynamics. This incorporates FUN's state-of-the-art concept of carbon cost theory and SWAT's strength in representing the impacts of agricultural management on the nitrogen cycle. Parameterizations for direct root and mycorrhizal-associated nitrogen uptake, leaf retranslocation, and symbiotic biological nitrogen fixation are employed from FUN, while parameterizations for nitrogen mineralization, nitrification, immobilization, volatilization, atmospheric deposition, and leaching are based on SWAT. The coupled model is then evaluated at the Kellogg Biological Station – a Long-term Ecological Research site within the U.S. Corn Belt. Results show that the model performs well in capturing the major nitrogen state/flux variables (e.g., soil nitrate and nitrate leaching). Furthermore, the addition of nitrogen dynamics improves the modeling of the carbon and water cycles (e.g., net primary productivity and evapotranspiration). The model improvement is expected to advance the capability of Noah-MP to simultaneously predict weather and water quality in fully coupled Earth system models.

scholarly journals Ability of the land surface model ISBA-A-gs to simulate leaf area index at the global scale: Comparison with satellites products

2006 ◽  
Vol 111 (D18) ◽  
Author(s):  
Anne-Laure Gibelin ◽  
Jean-Christophe Calvet ◽  
Jean-Louis Roujean ◽  
Lionel Jarlan ◽  
Sietse O. Los
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Land Surface ◽  
Land Surface Model ◽  
Global Scale ◽  
Surface Model ◽  
Area Index

scholarly journals A Python-enhanced urban land surface model SuPy (SUEWS in Python, v2019.2): development, deployment and demonstration

2019 ◽  
Author(s):  
Ting Sun ◽  
Sue Grimmond
Keyword(s):  
Land Surface ◽  
Urban Climate ◽  
Land Surface Model ◽  
Urban Land ◽  
Surface Model ◽  
Climate Modelling ◽  
Climate Services ◽  
Mass Fluxes ◽  
Online Tutorials ◽  
Urban Energy

Abstract. Accurate and agile modelling of the climate of cities is essential for urban climate services. The Surface Urban Energy and Water balance Scheme (SUEWS) is a state-of-the-art, widely used, urban land surface model (ULSM) which simulates urban-atmospheric interactions by quantifying the energy, water and mass fluxes. Using SUEWS as the computation kernel, SuPy (SUEWS in Python), stands on the Python-based data stack to streamline the pre-processing, computation and post-processing that are involved in the common modelling-centred urban climate studies. This paper documents the development of SuPy, which includes the SUEWS interface modification, F2PY (Fortran to Python) configuration and Python frontend implementation. In addition, the deployment of SuPy via PyPI (Python Package Index) is introduced along with the automated workflow for cross-platform compilation. This makes SuPy available for all mainstream operating systems (Windows, Linux, and macOS). Furthermore, three online tutorials in Jupyter notebooks are provided to users of different levels to become familiar with SuPy urban climate modelling. The SuPy package represents a significant enhancement that supports existing and new model applications, reproducibility, and enhanced functionality.

Contribution of lakes in the ORCHIDEE land surface model

2020 ◽  
Author(s):  
Anthony Bernus ◽  
Catherine Ottle ◽  
Nina Raoult
Keyword(s):  
Surface Temperature ◽  
Land Surface Temperature ◽  
Energy Budget ◽  
Land Surface ◽  
Land Surface Model ◽  
Global Scale ◽  
Heat Fluxes ◽  
Energy Budgets ◽  
Surface Model ◽  
Local Climate

<p>Lakes play a major role on local climate and boundary layer stratification. At global scale, they have been shown to have an impact on the energy budget, (see for example Le Moigne et al., 2016 or Bonan, 1995 ) . To represent the energy budget of lakes at a global scale, the FLake (Mironov et al, 2008) lake model has been coupled to the ORCHIDEE land surface model - the continental part of the IPSL earth system model. By including Flake in ORCHIDEE, we aim to improve the representation of land surface temperature and heat fluxes. Using the standard CMIP6 configuration of ORCHIDEE,  two 40-year simulations were generated (one coupled with FLake and one without) using the CRUJRA meteorological forcing data at a spatial resolution of 0.5°. We compare land surface temperatures and heat fluxes from the two ORCHIDEE simulations and assess the impacts of lakes on surface energy budgets. MODIS satellite land surface temperature products will be used to validate the simulations. We expect a better fit between the simulated land surface temperature and the MODIS data when the FLake configuration is used. The preliminary results of the comparison will be presented.</p>

scholarly journals Carbonyl sulfide: comparing a mechanistic representation of the vegetation uptake in a land surface model and the leaf relative uptake approach

2021 ◽  
Vol 18 (9) ◽  
pp. 2917-2955
Author(s):  
Fabienne Maignan ◽  
Camille Abadie ◽  
Marine Remaud ◽  
Linda M. J. Kooijmans ◽  
Kukka-Maaria Kohonen ◽  
...  
Keyword(s):  
Land Surface ◽  
Carbonyl Sulfide ◽  
Land Surface Model ◽  
Global Scale ◽  
C3 Plants ◽  
Surface Model ◽  
High Temporal Resolution ◽  
Co2 Uptake ◽  
Mechanistic Approach ◽  
Relative Uptake

Abstract. Land surface modellers need measurable proxies to constrain the quantity of carbon dioxide (CO2) assimilated by continental plants through photosynthesis, known as gross primary production (GPP). Carbonyl sulfide (COS), which is taken up by leaves through their stomates and then hydrolysed by photosynthetic enzymes, is a candidate GPP proxy. A former study with the ORCHIDEE land surface model used a fixed ratio of COS uptake to CO2 uptake normalised to respective ambient concentrations for each vegetation type (leaf relative uptake, LRU) to compute vegetation COS fluxes from GPP. The LRU approach is known to have limited accuracy since the LRU ratio changes with variables such as photosynthetically active radiation (PAR): while CO2 uptake slows under low light, COS uptake is not light limited. However, the LRU approach has been popular for COS–GPP proxy studies because of its ease of application and apparent low contribution to uncertainty for regional-scale applications. In this study we refined the COS–GPP relationship and implemented in ORCHIDEE a mechanistic model that describes COS uptake by continental vegetation. We compared the simulated COS fluxes against measured hourly COS fluxes at two sites and studied the model behaviour and links with environmental drivers. We performed simulations at a global scale, and we estimated the global COS uptake by vegetation to be −756 Gg S yr−1, in the middle range of former studies (−490 to −1335 Gg S yr−1). Based on monthly mean fluxes simulated by the mechanistic approach in ORCHIDEE, we derived new LRU values for the different vegetation types, ranging between 0.92 and 1.72, close to recently published averages for observed values of 1.21 for C4 and 1.68 for C3 plants. We transported the COS using the monthly vegetation COS fluxes derived from both the mechanistic and the LRU approaches, and we evaluated the simulated COS concentrations at NOAA sites. Although the mechanistic approach was more appropriate when comparing to high-temporal-resolution COS flux measurements, both approaches gave similar results when transporting with monthly COS fluxes and evaluating COS concentrations at stations. In our study, uncertainties between these two approaches are of secondary importance compared to the uncertainties in the COS global budget, which are currently a limiting factor to the potential of COS concentrations to constrain GPP simulated by land surface models on the global scale.

scholarly journals A high resolution global scale groundwater model

2014 ◽  
Vol 11 (5) ◽  
pp. 5217-5250 ◽  
Author(s):  
I. E. M. de Graaf ◽  
E. H. Sutanudjaja ◽  
L. P. H. van Beek ◽  
M. F. P. Bierkens
Keyword(s):  
Groundwater Flow ◽  
Land Surface ◽  
Regional Scale ◽  
Land Surface Model ◽  
Global Scale ◽  
Water Levels ◽  
Natural State ◽  
Surface Model ◽  
Groundwater Model ◽  
Aquifer Systems

Abstract. Groundwater is the world's largest accessible source of fresh water. It plays a vital role in satisfying needs for drinking water, agriculture and industrial activities. During times of drought groundwater sustains baseflow to rivers and wetlands, thereby supporting ecosystems. Most global scale hydrological models (GHMs) do not include a groundwater flow component, mainly due to lack of geohydrological data at the global scale. For the simulation of lateral flow and groundwater head dynamics a realistic physical representation of the groundwater system is needed, especially for GHMs that run at finer resolution. In this study we present a global scale groundwater model (run at 6' as dynamic steady state) using MODFLOW to construct an equilibrium water table at its natural state as the result of long-term climatic forcing. The aquifer schematization and properties were based on available global datasets of lithology and transmissivities combined with estimated aquifer thickness of an upper unconfined aquifer. The model is forced with outputs from the land-surface model PCR-GLOBWB, specifically with net recharge and surface water levels. A sensitivity analysis, in which the model was run with various parameter settings, showed variation in saturated conductivity causes most of the groundwater level variations. Simulated groundwater heads were validated against reported piezometer observations. The validation showed that groundwater depths are reasonably well simulated for many regions of the world, especially for sediment basins (R2 = 0.95). The simulated regional scale groundwater patterns and flowpaths confirm the relevance of taking lateral groundwater flow into account in GHMs. Flowpaths show inter-basin groundwater flow that can be a significant part of a basins water budget and helps to sustain river baseflow, explicitly during times of droughts. Also important aquifer systems are recharged by inter-basin groundwater flows that positively affect water availability.

scholarly journals A Python-enhanced urban land surface model SuPy (SUEWS in Python, v2019.2): development, deployment and demonstration

2019 ◽  
Vol 12 (7) ◽  
pp. 2781-2795 ◽  
Author(s):  
Ting Sun ◽  
Sue Grimmond
Keyword(s):  
Land Surface ◽  
Urban Climate ◽  
Land Surface Model ◽  
Urban Land ◽  
Surface Model ◽  
Climate Modelling ◽  
Mass Fluxes ◽  
Online Tutorials ◽  
Urban Energy ◽  
Cross Platform

Abstract. Accurate and agile modelling of cities weather, climate, hydrology and air quality is essential for integrated urban services. The Surface Urban Energy and Water balance Scheme (SUEWS) is a state-of-the-art widely used urban land surface model (ULSM) which simulates urban–atmospheric interactions by quantifying the energy, water and mass fluxes. Using SUEWS as the computation kernel, SuPy (SUEWS in Python) uses a Python-based data stack to streamline the pre-processing, computation and post-processing that are involved in the common modelling-centred urban climate studies. This paper documents the development of SuPy, including the SUEWS interface modification, F2PY (Fortran to Python) configuration and Python front-end implementation. In addition, the deployment of SuPy via PyPI (Python Package Index) is introduced along with the automated workflow for cross-platform compilation. This makes SuPy available for all mainstream operating systems (Windows, Linux and macOS). Three online tutorials in Jupyter Notebook are provided to users of different levels to become familiar with SuPy urban climate modelling. The SuPy package represents a significant enhancement that supports existing and new model applications, reproducibility and enhanced functionality.

Investigating vegetation role on UHI with mechanistic modelling worldwide

2021 ◽  
Author(s):  
Ziyan Zhang ◽  
Athanasios Paschalis ◽  
Ana Mijic ◽  
Naika Meili ◽  
Simone Fatichi
Keyword(s):  
Land Surface ◽  
Urban Areas ◽  
Energy Demand ◽  
Land Surface Model ◽  
Remote Sensing Data ◽  
Global Scale ◽  
Surface Model ◽  
Urban Fabric ◽  
Urban Energy ◽  
Set Up

<p>The urban heat island effect (UHI), defined as the temperature difference between urban areas and their surroundings, has been widely observed in many cities worldwide, impacting urban energy demand, citizen’s comfort and health. UHI intensities have been found to depend on background climate, and the urban fabric, including built (building thermal properties, heights, reflectance) and natural characteristics (vegetation cover, species composition, vegetation management). In this study, we focus on developing a global scale mechanistic understanding of how each of those properties alters the urban energy budget and leads to UHI development. To achieve this goal, we use the state-of-art urban ecohydrological and land-surface model (urban Tethys-Chloris) to perform a set of detailed UHI simulations for multiple large urban clusters across America, Europe and China in a 10-year time period (2009-2019), spanning a gradient of aridity, vegetation amount, and different compositions of the urban fabric. Model simulations were set up using the latest generation remote sensing data and climate reanalysis (ERA5). Using the simulations, we develop a paradigm of how UHIs develop worldwide, and propose viable solutions for sustainable UHI mitigation.</p>

Sign in / Sign up

Export Citation Format

Share Document