scholarly journals Incorporation of water vapor transfer in the JULES land surface model: Implications for key soil variables and land surface fluxes

2012 ◽  
Vol 48 (5) ◽  
Author(s):  
Raquel Garcia Gonzalez ◽  
Anne Verhoef ◽  
Pier Luigi Vidale ◽  
Isabelle Braud
Keyword(s):  
Water Vapor ◽  
Land Surface ◽  
Land Surface Model ◽  
Surface Fluxes ◽  
Surface Model ◽  
Vapor Transfer ◽  
Soil Variables ◽  
Water Vapor Transfer

Direct and Diffuse Radiation in the Shallow Cumulus–Vegetation System: Enhanced and Decreased Evapotranspiration Regimes

2017 ◽  
Vol 18 (6) ◽  
pp. 1731-1748 ◽  
Author(s):  
X. Pedruzo-Bagazgoitia ◽  
H. G. Ouwersloot ◽  
M. Sikma ◽  
C. C. van Heerwaarden ◽  
C. M. J. Jacobs ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Water Vapor ◽  
Land Surface ◽  
Land Surface Model ◽  
Diffuse Radiation ◽  
Surface Fluxes ◽  
Surface Model ◽  
Direct Radiation ◽  
Shallow Cumulus ◽  
Boundary Layer Dynamics

Abstract Guided by a holistic approach, the combined effects of direct and diffuse radiation on the atmospheric boundary layer dynamics over vegetated land are investigated on a daily scale. Three numerical experiments are designed that are aimed at disentangling the role of diffuse and direct radiation below shallow cumulus at the surface and on boundary layer dynamics. A large-eddy simulation (LES) model coupled to a land surface model is used, including a mechanistically immediate response of plants to radiation, temperature, and water vapor deficit changes. The partitioning in direct and diffuse radiation created by clouds and farther inside the canopy is explicitly accounted for. LES results are conditionally averaged as a function of the cloud optical depth. The findings show larger photosynthesis under thin clouds than under clear sky, due to an increase in diffuse radiation and a slight decrease in direct radiation. The reduced canopy resistance is the main driver for the enhanced carbon uptake by vegetation, while the carbon gradient and aerodynamic effects at the surface are secondary. Because of the coupling of CO2 and water vapor exchange through plant stomata, evapotranspiration is also enhanced under thin clouds, albeit to a lesser extent. This effect of diffuse radiation increases the water use efficiency and evaporative fraction under clouds. The dynamic perturbations of the surface fluxes by clouds do not affect general boundary layer or cloud characteristics because of the limited time and space where these perturbations occur. It is concluded that an accurate radiation partitioning calculation is necessary to obtain reliable estimations on local surface processes.

scholarly journals The Latest Improvements in SURFEX v8.0 of the Safran-Isba-Modcou Hydrometeorological Model over France

2020 ◽  
Author(s):  
Patrick Le Moigne ◽  
François Besson ◽  
Eric Martin ◽  
Julien Boé ◽  
Bertrand Decharme ◽  
...  
Keyword(s):  
Land Surface ◽  
Land Surface Model ◽  
Surface Fluxes ◽  
Surface Model ◽  
Resource Monitoring ◽  
Hydrogeological Model ◽  
Near Surface ◽  
Daily Streamflow ◽  
Soil Variables ◽  
Surface Scheme

Abstract. The Safran-Isba-Modcou (SIM) hydrometeorological system was developed and put into operations at Meteo-France in the early 2000's. SIM application is devoted to water resource monitoring, and therefore can help monitoring drought or forecasting flood risks over French territory. This complex system combines three models: SAFRAN analysis of near-surface meteorological variables, ISBA land surface model which aims at computing surface fluxes at the interface with the atmosphere and soil variables, and finally MODCOU a hydrogeological model which calculates river discharges and groundwater level evolutions. SIM model was improved first by reducing the SAFRAN infrared radiation bias, then by using the more advanced multi-layer diffusion surface scheme of ISBA to have a more physical representation of the surface and soil processes. At the same time more accurate and up-to-date input databases for vegetation, soil texture and orography were used and finally in mountainous areas a subgrid representation of the orography using elevation bands was adopted as well as the possibility to add a reservoir to represent the effect of aquifers in mountains. SIM model was run for a 60y period from 1958 to 2018. The present paper describes the changes and demonstrates that the SIM new version performs better than the previous one by comparing a set of selected simulations to measurements of daily streamflow and observations of snow depths.

ECLand: an ECMWF land surface modelling platform

2021 ◽  
Author(s):  
Gianpaolo Balsamo ◽  
Souhail Boussetta
Keyword(s):  
Land Surface ◽  
Urban Areas ◽  
Land Surface Model ◽  
Open Water ◽  
Surface Fluxes ◽  
Surface Model ◽  
New Developments ◽  
Surface Modelling ◽  
Land Surface Modelling ◽  
New Research

<p>The ECMWF operational land surface model, based on the Carbon-Hydrology Tiled ECMWF Scheme for Surface Exchanges over Land (CHTESSEL) is the baseline for global weather, climate and environmental applications at ECMWF. In order to expedite its progress and benefit from international collaboration, an ECLand platform has been designed to host advanced and modular schemes. ECLand is paving the way toward a land model that could support a wider range of modelling applications, facilitating global kilometer scales testing as envisaged in the Copernicus and Destination Earth programmes. This presentation introduces the CHTESSEL and its recent new developments that aims at hosting new research applications.</p><p>These new improvements touch upon different components of the model: (i) vegetation, (ii) snow, (iii) soil hydrology, (iv) open water/lakes (v) rivers and (vi) urban areas. The developments are evaluated separately with either offline simulations or coupled experiments, depending on their level of operational readiness, illustrating the benchmarking criteria for assessing process fidelity with regards to land surface fluxes and reservoirs involved in water-energy-carbon exchange, and within the Earth system prediction framework, as foreseen to enter upcoming ECMWF operational cycles.</p><p>Reference: Souhail Boussetta, Gianpaolo Balsamo*, Anna Agustì-Panareda, Gabriele Arduini, Anton Beljaars, Emanuel Dutra, Glenn Carver, Margarita Choulga, Ioan Hadade, Cinzia Mazzetti, Joaquìn Munõz-Sabater, Joe McNorton, Christel Prudhomme, Patricia De Rosnay, Irina Sandu, Nils Wedi, Dai Yamazaki, Ervin Zsoter, 2021: ECLand: an ECMWF land surface modelling platform, MDPI Atmosphere, (in prep).</p>

scholarly journals Modeling Land Surface Fluxes from Uncertain Rainfall: A Case Study in the Sahel with Field-Driven Stochastic Rainfields

Atmosphere ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 465
Author(s):  
Bernard Cappelaere ◽  
Denis Feurer ◽  
Théo Vischel ◽  
Catherine Ottlé ◽  
Hassane Bil-Assanou Issoufou ◽  
...  
Keyword(s):  
Land Surface ◽  
Monsoon Season ◽  
Land Surface Model ◽  
Surface Fluxes ◽  
Energy Budgets ◽  
Substantial Part ◽  
Surface Model ◽  
Time Space ◽  
Flux Variability ◽  
Sahel Region

In distributed land surface modeling (LSM) studies, uncertainty in the rainfields that are used to force models is a major source of error in predicted land surface response variables. This is particularly true for applications in the African Sahel region, where weak knowledge of highly time/space-variable convective rainfall in a poorly monitored region is a considerable obstacle to such developments. In this study, we used a field-based stochastic rainfield generator to analyze the propagation of the rainfall uncertainty through a distributed land surface model simulating water and energy fluxes in Sahelian ecosystems. Ensemble time/space rainfields were generated from field observations of the local AMMA-CATCH-Niger recording raingauge network. The rainfields were then used to force the SEtHyS-Savannah LSM, yielding an ensemble of time/space simulated fluxes. Through informative graphical representations and innovative diagnosis metrics, these outputs were analyzed to separate the different components of flux variability, among which was the uncertainty represented by ensemble-wise variability. Scale dependence was analyzed for each flux type in the water and energy budgets, producing a comprehensive picture of uncertainty propagation for the various flux types, with its relationship to intrinsic space/time flux variability. The study was performed over a 2530 km2 domain over six months, covering an entire monsoon season and the subsequent dry-down, using a kilometer/daily base resolution of analysis. The newly introduced dimensionless uncertainty measure, called the uncertainty coefficient, proved to be more effective in describing uncertainty patterns and relationships than a more classical measure based on variance fractions. Results show a clear scaling relationship in uncertainty coefficients between rainfall and the dependent fluxes, specific to each flux type. These results suggest a higher sensitivity to rainfall uncertainty for hydrological than for agro-ecological or meteorological applications, even though eddy fluxes do receive a substantial part of that source uncertainty.

scholarly journals Influence of thermodynamic soil and vegetation parameterizations on the simulation of soil temperature states and surface fluxes by the Noah LSm over a Tibetan plateau site

2009 ◽  
Vol 6 (1) ◽  
pp. 455-499 ◽  
Author(s):  
R. van der Velde ◽  
Z. Su ◽  
M. Ek ◽  
M. Rodell ◽  
Y. Ma
Keyword(s):  
Thermal Properties ◽  
Tibetan Plateau ◽  
Land Surface ◽  
Land Surface Model ◽  
Soil Heat Flux ◽  
Stomatal Resistance ◽  
Surface Fluxes ◽  
Surface Model ◽  
The Tibetan Plateau ◽  
Soil Thermal Properties

Abstract. In this paper, we investigate the ability of the Noah Land Surface model (LSm) to simulate temperature states in the soil profile and surface fluxes measured during a 7-day dry period at a micrometeorological station on the Tibetan Plateau. Adjustments in soil and vegetation parameterizations required to ameliorate the Noah simulation on these two aspects are presented, which include: (1) Differentiating the soil thermal properties of top- and subsoils, (2) Investigation of the different numerical soil discretizations and (3) Calibration of the parameters utilized to describe the transpiration dynamics of the Plateau vegetation. Through the adjustments in the parameterization of the soil thermal properties (STP) simulation of the soil heat transfer is improved, which results in a reduction of Root Mean Squared Differences (RMSD's) by 14%, 18% and 49% between measured and simulated skin, 5-cm and 25-cm soil temperatures, respectively. Further, decreasing the minimum stomatal resistance (Rc, min) and the optimum temperature for transpiration (Topt) of the vegetation parameterization reduces RMSD's between measured and simulated energy balance components by 30%, 20% and 5% for the sensible, latent and soil heat flux, respectively.

Assessment of the uncertainty related to irrigation modeling by a land surface model across India

2020 ◽  
Author(s):  
Dazhi Li ◽  
Xujun Han ◽  
Dhanya C.t. ◽  
Stefan Siebert ◽  
Harry Vereecken ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Land Surface ◽  
Monsoon Season ◽  
Land Surface Model ◽  
Surface Fluxes ◽  
Spatiotemporal Pattern ◽  
Surface Model ◽  
Irrigation Requirement ◽  
Community Land Model ◽  
Surface Models

<p>Irrigation is very important for maintaining the agricultural production and sustaining the increasing population of India. The irrigation requirement can be estimated with land surface models by modeling water storage changes but the estimates are affected by various uncertainties such as regarding the spatiotemporal distribution of areas where and when irrigation is potentially applied. In the present work, this uncertainty is analyzed for the whole Indian domain. The irrigation requirements and hydrological fluxes over India were reconstructed by multiple simulation experiments with the Community Land Model (CLM) version 4.5 for the year of 2010.</p><p>These multiple simulation scenarios showed that the modeled irrigation requirement and the land surface fluxes differed between the scenarios, representing the spatiotemporal uncertainty of the irrigation maps. Using a season-specific irrigation map resulted in a higher transpiration-evapotranspiration ratio (T/ET) in the pre-monsoon season compared to the application of a static irrigation map, which implies a higher irrigation efficiency. The remote sensing based evapotranspiration products GLEAM and MODIS ET were used for comparison, showing a similar increasing ET-trend in the pre-monsoon season as the irrigation induced land surface modeling. The correspondence is better if the seasonal irrigation map is used as basis for simulations with CLM. We conclude that more accurate temporal information on irrigation results in modeled evapotranspiration closer to the spatiotemporal pattern of evapotranspiration deduced from remote sensing. Another conclusion is that irrigation modeling should consider the sub-grid heterogeneity to improve the estimation of soil water deficit and irrigation requirement.</p>

scholarly journals WRFv3.2-SPAv2: development and validation of a coupled ecosystem–atmosphere model, scaling from surface fluxes of CO<sub>2</sub> and energy to atmospheric profiles

2013 ◽  
Vol 6 (4) ◽  
pp. 1079-1093 ◽  
Author(s):  
T. L. Smallman ◽  
J. B. Moncrieff ◽  
M. Williams
Keyword(s):  
Air Temperature ◽  
Land Surface ◽  
Wrf Model ◽  
Land Surface Model ◽  
Net Ecosystem Exchange ◽  
Terrestrial Ecosystem ◽  
Surface Fluxes ◽  
Surface Model ◽  
Terrestrial Ecosystem Model ◽  
Atmospheric Profiles

Abstract. The Weather Research and Forecasting meteorological (WRF) model has been coupled to the Soil–Plant–Atmosphere (SPA) terrestrial ecosystem model, to produce WRF-SPA. SPA generates realistic land–atmosphere exchanges through fully coupled hydrological, carbon and energy cycles. The addition of a~land surface model (SPA) capable of modelling biospheric CO2 exchange allows WRF-SPA to be used for investigating the feedbacks between biosphere carbon balance, meteorology, and land use and land cover change. We have extensively validated WRF-SPA using multi-annual observations of air temperature, turbulent fluxes, net radiation and net ecosystem exchange of CO2 at three sites, representing the dominant vegetation types in Scotland (forest, managed grassland and arable agriculture). For example air temperature is well simulated across all sites (forest R2 = 0.92, RMSE = 1.7 °C, bias = 0.88 °C; managed grassland R2 = 0.73, RMSE = 2.7 °C, bias = −0.30 °C; arable agriculture R2 = 0.82, RMSE = 2.2 °C, bias = 0.46 °C; RMSE, root mean square error). WRF-SPA generates more realistic seasonal behaviour at the site level compared to an unmodified version of WRF, such as improved simulation of seasonal transitions in latent heat flux in arable systems. WRF-SPA also generates realistic seasonal CO2 exchanges across all sites. WRF-SPA is also able to realistically model atmospheric profiles of CO2 over Scotland, spanning a 3 yr period (2004–2006), capturing both profile structure, indicating realistic transport, and magnitude (model–data residual

scholarly journals Development of a Land Surface Model Including Evaporation and Adsorption Processes in the Soil for the Land–Air Exchange in Arid Regions

2007 ◽  
Vol 8 (6) ◽  
pp. 1307-1324 ◽  
Author(s):  
Genki Katata ◽  
Haruyasu Nagai ◽  
Hiromasa Ueda ◽  
Nurit Agam ◽  
Pedro R. Berliner
Keyword(s):  
Water Vapor ◽  
Soil Water ◽  
Land Surface ◽  
Soil Layer ◽  
Land Surface Model ◽  
Ground Surface ◽  
Surface Model ◽  
Water Vapor Flux ◽  
Vapor Flux ◽  
Adsorption Processes

Abstract A one-dimensional soil model has been developed to better predict heat and water exchanges in arid and semiarid regions. New schemes to calculate evaporation and adsorption in the soil were incorporated in the model. High performance of the model was confirmed by comparison of predicted surface fluxes, soil temperature, and volumetric soil water content with those measured in the Negev Desert, Israel. Evaporation and adsorption processes in the soil have a large impact on the heat and water exchange between the atmosphere and land surface and are necessary to accurately predict them. Numerical experiments concerning the drying process of soil are performed using the presented model and a commonly used land surface model. The results indicated that, when the dry soil layer (DSL) develops, water vapor flux to the atmosphere is caused by evaporation in the soil rather than evaporation at the ground surface. Moreover, the adsorption process has some impact on the water and heat balance at the ground surface. The upward water vapor flux during the daytime is due to evaporation of soil water in the DSL, which is stored during the night due to adsorption. When the DSL progresses sufficiently, almost the same amounts of water are exchanged between the air and the soil surface by daytime evaporation and nighttime adsorption. In such conditions, latent heat due to evaporation and adsorption in the soil also work to reduce the diurnal variation of surface temperature.

scholarly journals Evaluation of the Noah land-surface model using data from a fair-weather IHOP_2002 day with heterogeneous surface fluxes

2007 ◽  
Vol preprint (2008) ◽  
pp. 1
Author(s):  
Margaret A. LeMone ◽  
Mukul Tewari ◽  
Fei Chen ◽  
Joseph G. Alfieri ◽  
Dev Niyogi
Keyword(s):  
Land Surface ◽  
Land Surface Model ◽  
Surface Fluxes ◽  
Heterogeneous Surface ◽  
Surface Model ◽  
Fair Weather ◽  
Noah Land Surface Model ◽  
Using Data

scholarly journals On the Representativeness of UTOPIA Land Surface Model for Creating a Database of Surface Layer, Vegetation and Soil Variables in Piedmont Vineyards, Italy

2019 ◽  
Vol 9 (18) ◽  
pp. 3880 ◽  
Author(s):  
Claudio Cassardo ◽  
Valentina Andreoli
Keyword(s):  
Land Surface ◽  
Measurement Errors ◽  
Land Surface Model ◽  
Heat Fluxes ◽  
Surface Model ◽  
Turbulent Heat ◽  
Soil Variables ◽  
Exchange Processes ◽  
Nw Italy ◽  
Land Data Assimilation System

The main aim of the paper is to show how, and how many, simulations carried out using the Land Surface Model UTOPIA (University of TOrino model of land Process Interaction with Atmosphere) are representative of the micro-meteorological conditions and exchange processes at the atmosphere/biosphere interface, with a particular focus on heat and hydrologic transfers, over an area of the Piemonte (Piedmont) region, NW Italy, which is characterized by the presence of many vineyards. Another equally important aim is to understand how much the quality of the simulation outputs was influenced by the input data, whose measurements are often unavailable for long periods over country areas at an hourly basis. Three types of forcing data were used: observations from an experimental campaign carried out during the 2008, 2009, and 2010 vegetative seasons in three vineyards, and values extracted from the freely available Global Land Data Assimilation System (GLDAS, versions 2.0 and 2.1). Since GLDAS also contains the outputs of the simulations performed using the Land Surface Model NOAH, an additional intercomparison between the two models, UTOPIA and NOAH, both driven by the same GLDAS datasets, was performed. The intercomparisons were performed on the following micro-meteorological variables: net radiation, sensible and latent turbulent heat fluxes, and temperature and humidity of soil. The results of this study indicate that the methodology of employing land surface models driven by a gridded database to evaluate variables of micro-meteorological and agronomic interest in the absence of observations is suitable and gives satisfactory results, with uncertainties comparable to measurement errors, thus, allowing us to also evaluate some time trends. The comparison between GLDAS2.0 and GLDAS2.1 indicates that the latter generally produces simulation outputs more similar to the observations than the former, using both UTOPIA and NOAH models.

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