scholarly journals A land surface model combined with a crop growth model for paddy rice (MATCRO-Rice Ver. 1) – Part II: Model validation

2016 ◽  
Author(s):  
Yuji Masutomi ◽  
Keisuke Ono ◽  
Takahiro Takimoto ◽  
Masayoshi Mano ◽  
Atsushi Maruyama ◽  
...  
Keyword(s):  
Heat Flux ◽  
Crop Yield ◽  
Land Surface ◽  
Carbon Flux ◽  
Sensible Heat Flux ◽  
Land Surface Model ◽  
Paddy Rice ◽  
Surface Model ◽  
The Mean ◽  
Mean Square Errors

Abstract. We conducted a comprehensive validation of the simulations by MATCRO-Rice developed by Masutomi et al. (2016). In the validation, we compared simulations with observations for latent heat flux (LHF), sensible heat flux (SHF), net carbon flux, and paddy rice yield from 2003 to 2006. The observation site used for the comparison is located in Tsukuba, Japan, where inputs for running the model and outputs for the validation were fully observed. The 4-year average root mean square errors (RMSEs) between simulations and observations for LHF and SHF were 18.57 and 12.66 W m−2, respectively. These values for errors are comparable to those reported in earlier studies. The comparison of biomass growth during growing periods from 2003 to 2006 shows that the simulations were in agreement with the observations, indicating that the model can reproduce the net carbon flux well. The 4-year average RMSE for crop yield in the same period was 402.4 kg ha−1, which accounted for 7.9 % of the mean observed yields. These results indicate that MATCRO-Rice has high ability to accurately and consistently simulate LHF, SHF, net carbon flux, and crop yield.

scholarly journals A land surface model combined with a crop growth model for paddy rice (MATCRO-Rice v. 1) – Part 2: Model validation

2016 ◽  
Vol 9 (11) ◽  
pp. 4155-4167 ◽  
Author(s):  
Yuji Masutomi ◽  
Keisuke Ono ◽  
Takahiro Takimoto ◽  
Masayoshi Mano ◽  
Atsushi Maruyama ◽  
...  
Keyword(s):  
Heat Flux ◽  
Crop Yield ◽  
Land Surface ◽  
Crop Yields ◽  
Sensible Heat Flux ◽  
Paddy Rice ◽  
Surface Model ◽  
Model Parameters ◽  
Carbon Uptake ◽  
Mean Square Errors

Abstract. We conducted two types of validation for the simulations by MATCRO-Rice developed by Masutomi et al. (2016). In the first validation, we compared simulations with observations for latent heat flux (LHF), sensible heat flux (SHF), net carbon uptake by crop, and paddy rice yield from 2003 to 2006 at the site where model parameters are parameterized. In the second validation, we compared the observed and simulated paddy rice yields over Japan from 1991 to 2010 between observations and simulations. The 4-year average root mean square errors (RMSEs) of the first validation for LHF and SHF were 18.20 and 15.47 W m−2, respectively. These values for errors are comparable to those reported in earlier studies. The comparison of biomass growth during growing periods from 2003 to 2006 at the parameterization site shows that the simulations were in agreement with the observations, indicating that the model can reproduce the net carbon uptake by crops well. The 4-year average RMSE of the first validation for crop yield in the same period was 410.6 kg ha−1, which accounted for 8.1 % of the mean observed yields. The error of the second validation for crop yield was 16.7 % and the correlation of crop yields between observations and simulations from 1991 to 2010 was significant at 0.663 (P < 0.01). These results indicate that MATCRO-Rice has high ability to accurately and consistently simulate LHF, SHF, net carbon uptake by crop, and crop yield.

scholarly journals Assimilation of Satellite-Derived Skin Temperature Observations into Land Surface Models

2010 ◽  
Vol 11 (5) ◽  
pp. 1103-1122 ◽  
Author(s):  
Rolf H. Reichle ◽  
Sujay V. Kumar ◽  
Sarith P. P. Mahanama ◽  
Randal D. Koster ◽  
Q. Liu
Keyword(s):  
Heat Flux ◽  
Data Assimilation ◽  
Skin Temperature ◽  
Land Surface ◽  
Sensible Heat Flux ◽  
Land Surface Model ◽  
Open Loop ◽  
Surface Model ◽  
Ground Heat Flux ◽  
Assimilation System

Abstract Land surface (or “skin”) temperature (LST) lies at the heart of the surface energy balance and is a key variable in weather and climate models. In this research LST retrievals from the International Satellite Cloud Climatology Project (ISCCP) are assimilated into the Noah land surface model and Catchment land surface model (CLSM) using an ensemble-based, offline land data assimilation system. LST is described very differently in the two models. A priori scaling and dynamic bias estimation approaches are applied because satellite and model LSTs typically exhibit different mean values and variabilities. Performance is measured against 27 months of in situ measurements from the Coordinated Energy and Water Cycle Observations Project at 48 stations. LST estimates from Noah and CLSM without data assimilation (“open loop”) are comparable to each other and superior to ISCCP retrievals. For LST, the RMSE values are 4.9 K (CLSM), 5.5 K (Noah), and 7.6 K (ISCCP), and the anomaly correlation coefficients (R) are 0.61 (CLSM), 0.63 (Noah), and 0.52 (ISCCP). Assimilation of ISCCP retrievals provides modest yet statistically significant improvements (over an open loop, as indicated by nonoverlapping 95% confidence intervals) of up to 0.7 K in RMSE and 0.05 in the anomaly R. The skill of the latent and sensible heat flux estimates from the assimilation integrations is essentially identical to the corresponding open loop skill. Noah assimilation estimates of ground heat flux, however, can be significantly worse than open loop estimates. Provided the assimilation system is properly adapted to each land model, the benefits from the assimilation of LST retrievals are comparable for both models.

scholarly journals On the use of the post-closure methods uncertainty band to evaluate the performance of land surface models against eddy covariance flux data

2015 ◽  
Vol 12 (8) ◽  
pp. 2311-2326 ◽  
Author(s):  
J. Ingwersen ◽  
K. Imukova ◽  
P. Högy ◽  
T. Streck
Keyword(s):  
Heat Flux ◽  
Energy Balance ◽  
Eddy Covariance ◽  
Land Surface ◽  
Sensible Heat Flux ◽  
Land Surface Model ◽  
Bowen Ratio ◽  
Surface Model ◽  
Flux Data ◽  
Uncertainty Band

Abstract. The energy balance of eddy covariance (EC) flux data is normally not closed. Therefore, at least if used for modelling, EC flux data are usually post-closed, i.e. the measured turbulent fluxes are adjusted so as to close the energy balance. At the current state of knowledge, however, it is not clear how to partition the missing energy in the right way. Eddy flux data therefore contain some uncertainty due to the unknown nature of the energy balance gap, which should be considered in model evaluation and the interpretation of simulation results. We propose to construct the post-closure methods uncertainty band (PUB), which essentially designates the differences between non-adjusted flux data and flux data adjusted with the three post-closure methods (Bowen ratio, latent heat flux (LE) and sensible heat flux (H) method). To demonstrate this approach, simulations with the NOAH-MP land surface model were evaluated based on EC measurements conducted at a winter wheat stand in southwest Germany in 2011, and the performance of the Jarvis and Ball–Berry stomatal resistance scheme was compared. The width of the PUB of the LE was up to 110 W m−2 (21% of net radiation). Our study shows that it is crucial to account for the uncertainty in EC flux data originating from lacking energy balance closure. Working with only a single post-closing method might result in severe misinterpretations in model–data comparisons.

scholarly journals Simulation of Surface Fluxes in Two Distinct Environments along a Topographic Gradient in a Central Amazonian Forest using the INtegrated LAND Surface Model

2017 ◽  
Author(s):  
Elisângela Broedel ◽  
Celso Von Randow ◽  
Luz Adriana Cuartas ◽  
Antonio Donato Nobre ◽  
Alessandro Carioca de Araújo ◽  
...  
Keyword(s):  
Heat Flux ◽  
Land Surface ◽  
Sensible Heat Flux ◽  
Land Surface Model ◽  
Net Ecosystem Exchange ◽  
Surface Fluxes ◽  
Surface Model ◽  
Terra Firme ◽  
Topographic Gradient ◽  
Valley Area

Abstract. The Integrated Land Surface model (INLAND) land surface model, in offline mode, was adjusted and forced with prescribed climate to represent two contrasting environments along a topographic gradient in a central Amazon Terra Firme forest, which is distinguished by well-drained, flat plateaus and poorly drained, broad river valleys. To correctly simulate the valley area, a lumped unconfined aquifer model was included in the INLAND model to represent the water table dynamics and results show reasonable agreement with observations. Field data from both areas are used to evaluate the model simulations of energy, water and carbon fluxes. The model is able to characterize with good accuracy the main differences that appear in the seasonal energy and carbon partitioning of plateau and valley fluxes, which are related to features of the vegetation associated with soils and topography. The simulated latent heat flux (LE) and net ecosystem exchange of carbon (NEE), for example, are higher on the plateau area while at the bottom of the valley the sensible heat flux (H) is noticeably higher than at the plateau, in agreement with observed data. Differences in simulated hydrological fluxes are also linked to the topography, showing a higher surface runoff (R) and lower evapotranspiration (ET) in the valley area. The different behavior of the fluxes on both annual and diurnal time scales confirms the benefit of a tiling mechanism in the presence of large contrast and the importance to incorporate subgrid-scale variability by including relief attributes of topography, soil and vegetation to better representing Terra Firme forests in land surface models.

scholarly journals Evaluation of the Soil, Vegetation, and Snow (SVS) Land Surface Model for the Simulation of Surface Energy Fluxes and Soil Moisture under Snow-Free Conditions

Atmosphere ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 278 ◽  
Author(s):  
Gonzalo Leonardini ◽  
François Anctil ◽  
Maria Abrahamowicz ◽  
Étienne Gaborit ◽  
Vincent Vionnet ◽  
...  
Keyword(s):  
Heat Flux ◽  
Soil Moisture ◽  
Land Surface ◽  
Sensible Heat Flux ◽  
Land Surface Model ◽  
Soil Heat Flux ◽  
Heat Fluxes ◽  
Surface Model ◽  
Point Scale ◽  
Energy Fluxes

The recently developed Soil, Vegetation, and Snow (SVS) land surface model is being progressively implemented at Environment and Climate Change Canada (ECCC) for operational numerical weather and hydrological predictions. The objective of this study is to evaluate the ability of SVS, in offline point-scale mode and under snow-free conditions, to simulate the surface heat fluxes and soil moisture when compared to flux tower observations and simulations from the Canadian Land Surface Scheme (CLASS), used here as a benchmark model. To do this, we performed point-scale simulations of between 4 and 12 years of data records at six selected sites of the FLUXNET network under arid, Mediterranean and tropical climates. At all sites, SVS shows realistic simulations of latent heat flux, sensible heat flux and net radiation. Soil heat flux is reasonably well simulated for the arid sites and one Mediterranean site and poorly simulated for the tropical sites. On the other hand, surface soil moisture was reasonably well simulated at the arid and Mediterranean sites and poorly simulated at the tropical sites. SVS performance was comparable to CLASS not only for energy fluxes and soil moisture, but also for more specific processes such as evapotranspiration and water balance.

scholarly journals Assessment of Roughness Length Schemes Implemented within the Noah Land Surface Model for High-Altitude Regions

2014 ◽  
Vol 15 (3) ◽  
pp. 921-937 ◽  
Author(s):  
Donghai Zheng ◽  
Rogier van der Velde ◽  
Zhongbo Su ◽  
Martijn J. Booij ◽  
Arjen Y. Hoekstra ◽  
...  
Keyword(s):  
Heat Flux ◽  
High Altitude ◽  
Land Surface ◽  
Land Surface Model ◽  
Surface Heat ◽  
Heat Fluxes ◽  
Surface Model ◽  
Surface Heat Fluxes ◽  
Noah Land Surface Model ◽  
Better Than

ABSTRACT Current land surface models still have difficulties with producing reliable surface heat fluxes and skin temperature (Tsfc) estimates for high-altitude regions, which may be addressed via adequate parameterization of the roughness lengths for momentum (z0m) and heat (z0h) transfer. In this study, the performance of various z0h and z0m schemes developed for the Noah land surface model is assessed for a high-altitude site (3430 m) on the northeastern part of the Tibetan Plateau. Based on the in situ surface heat fluxes and profile measurements of wind and temperature, monthly variations of z0m and diurnal variations of z0h are derived through application of the Monin–Obukhov similarity theory. These derived values together with the measured heat fluxes are utilized to assess the performance of those z0m and z0h schemes for different seasons. The analyses show that the z0m dynamics are related to vegetation dynamics and soil water freeze–thaw state, which are reproduced satisfactorily with current z0m schemes. Further, it is demonstrated that the heat flux simulations are very sensitive to the diurnal variations of z0h. The newly developed z0h schemes all capture, at least over the sparse vegetated surfaces during the winter season, the observed diurnal variability much better than the original one. It should, however, be noted that for the dense vegetated surfaces during the spring and monsoon seasons, not all newly developed schemes perform consistently better than the original one. With the most promising schemes, the Noah simulated sensible heat flux, latent heat flux, Tsfc, and soil temperature improved for the monsoon season by about 29%, 79%, 75%, and 81%, respectively. In addition, the impact of Tsfc calculation and energy balance closure associated with measurement uncertainties on the above findings are discussed, and the selection of the appropriate z0h scheme for applications is addressed.

scholarly journals Intercomparison between the Integrated Urban land Model and the Noah Urban Canopy Model

2020 ◽  
Author(s):  
Chunlei Meng ◽  
Junxia Dou
Keyword(s):  
Heat Flux ◽  
Solar Radiation ◽  
Human Activity ◽  
Land Surface ◽  
Land Surface Model ◽  
Urban Canopy ◽  
Urban Land ◽  
Surface Model ◽  
Urban Canopy Model ◽  
Canopy Model

Abstract. Urban land surface model (ULSM) is an important tool to study the climatic effect of human activity. Now there are two main methods to parameterize the effects of human activity, the coupling method and the integrating method. For the coupled method, the urban canopy model (UCM) was developed and coupled with the land surface model for the natural land surfaces. For the integrated method, the urban land surface model was built directly based on the traditional land surface model. In this paper, the Noah Single Layer Urban Canopy Model (Noah/SLUCM) and the Integrated Urban land Model (IUM) were compared using the observed fluxes data at the 325-meter meteorology tower in Beijing. Through the comparison, the key factors and physical processes of the urban land surface model which have significant impact on the performance of ULSM were found out. The results indicate that the absorbed solar radiation of urban surface was reduced by the solar radiation scattering, the absorption of building roof and wall, and the shading effect of urban canopy and tall buildings. Urban surface roughness length and friction velocity are important in urban sensible heat flux simulation. Urban water balance and impervious surface evaporation (ISE) are important in urban latent heat flux simulation.

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