Sensitivity of high resolution WRF model to land surface schemes in simulating boreal summer climate over Central Asia

2020 ◽  
Author(s):  
Sha Lu ◽  
Weidong Guo ◽  
Yongkang Xue ◽  
Fang Huang
Keyword(s):  
High Resolution ◽  
Central Asia ◽  
Land Surface ◽  
Model Simulation ◽  
Sensible Heat Flux ◽  
Wrf Model ◽  
Boreal Summer ◽  
Adjustment Process ◽  
Land Surface Scheme ◽  
Surface Scheme

<p>The Land surface scheme is crucial for the performance of regional climate models in dynamic downscaling application. In this study, we investigate the sensitivity of the simulation  with high resolution (10km) WRF model to the land surface schemes over Central Asia. The high resolution WRF simulations for 19 summers from 2000 to 2018 are conducted with four different land surface schemes (hereafter referred to as Exp-CLM, Exp-Noah-MP, Exp-PX and Exp-SSiB, respectively). The initial and boundary conditions for the WRF model simulations are provided from the NCEP-FNL analysis product. The ERA-Interim reanalysis (ERA), the GHCN-CAMS (CAMS) and the CRU gridded data are used to comprehensively evaluate the WRF simulations. Compared with verification data, the WRF model with high resolution can reasonably reproduce the spatial patterns of summer mean large scale atmospheric circulation, 2-m temperature and precipitation. The simulation results, however, are sensitive to the option of land surface scheme. The performance of Exp-CLM4 and Exp-SSiB are better than that of Exp-Noah-MP and Exp-PX assessed by the multivariable integrated evaluation method. To comprehensively understand the dynamic and physical mechanisms behind the WRF model sensitivity to land surface schemes, the differences in the surface energy balance between the ensemble means Ens-CLM4-SSiB and Ens-NoanMP-PX are analyzed in detail. The results demonstrate that the intensity of the simulated sensible heat flux over Central Asia is weaker in Ens-CLM4-SSiB than that in Ens-NoahMP-PX. As a result, large differences in geopotential height occur over the model simulation domain. The simulated wind fields are subsequently affected due to the geostrophic adjustment process, thus the simulation of 2-m temperature, precipitation, surface soil moisture and surface skin temperature are all affected.</p>

scholarly journals Comparative Analysis of High-Resolution Soil Moisture Simulations from the Soil, Vegetation, and Snow (SVS) Land Surface Model Using SAR Imagery Over Bare Soil

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 542 ◽  
Author(s):  
Mohammed Dabboor ◽  
Leqiang Sun ◽  
Marco Carrera ◽  
Matthew Friesen ◽  
Amine Merzouki ◽  
...  
Keyword(s):  
Soil Moisture ◽  
High Resolution ◽  
Soil Texture ◽  
Land Surface ◽  
Goodness Of Fit ◽  
Retrieval Algorithm ◽  
Surface Model ◽  
Land Surface Scheme ◽  
Sar Imagery ◽  
Surface Scheme

Soil moisture is a key variable in Earth systems, controlling the exchange of water andenergy between land and atmosphere. Thus, understanding its spatiotemporal distribution andvariability is important. Environment and Climate Change Canada (ECCC) has developed a newland surface parameterization, named the Soil, Vegetation, and Snow (SVS) scheme. The SVS landsurface scheme features sophisticated parameterizations of hydrological processes, including watertransport through the soil. It has been shown to provide more accurate simulations of the temporaland spatial distribution of soil moisture compared to the current operational land surface scheme.Simulation of high resolution soil moisture at the field scale remains a challenge. In this study, wesimulate soil moisture maps at a spatial resolution of 100 m using the SVS land surface scheme overan experimental site located in Manitoba, Canada. Hourly high resolution soil moisture maps wereproduced between May and November 2015. Simulated soil moisture values were compared withestimated soil moisture values using a hybrid retrieval algorithm developed at Agriculture andAgri-Food Canada (AAFC) for soil moisture estimation using RADARSAT-2 Synthetic ApertureRadar (SAR) imagery. Statistical analysis of the results showed an overall promising performanceof the SVS land surface scheme in simulating soil moisture values at high resolution scale.Investigation of the SVS output was conducted both independently of the soil texture, and as afunction of the soil texture. The SVS model tends to perform slightly better over coarser texturedsoils (sandy loam, fine sand) than finer textured soils (clays). Correlation values of the simulatedSVS soil moisture and the retrieved SAR soil moisture lie between 0.753–0.860 over sand and 0.676-0.865 over clay, with goodness of fit values between 0.567–0.739 and 0.457–0.748, respectively. TheRoot Mean Square Difference (RMSD) values range between 0.058–0.062 over sand and 0.055–0.113over clay, with a maximum absolute bias of 0.049 and 0.094 over sand and clay, respectively. Theunbiased RMSD values lie between 0.038–0.057 over sand and 0.039–0.064 over clay. Furthermore,results show an Index of Agreement (IA) between the simulated and the derived soil moisturealways higher than 0.90.

scholarly journals Simulation of summer climate over Central Asia shows high sensitivity to different land surface schemes in WRF

2021 ◽  
Author(s):  
Sha Lu ◽  
Weidong Guo ◽  
Yongkang Xue ◽  
Fang Huang ◽  
Jun Ge
Keyword(s):  
Central Asia ◽  
Land Surface ◽  
Large Scale ◽  
Climate Models ◽  
Global Analysis ◽  
Regional Climate ◽  
Wrf Model ◽  
Heat Fluxes ◽  
Ensemble Average ◽  
Adjustment Process

AbstractLand surface processes are vital to the performance of regional climate models in dynamic downscaling application. In this study, we investigate the sensitivity of the simulation by using the weather research and forecasting (WRF) model at 10-km resolution to the land surface schemes over Central Asia. The WRF model was run for 19 summers from 2000 to 2018 configured with four different land surface schemes including CLM4, Noah-MP, Pleim-Xiu and SSiB, hereafter referred as Exp-CLM4, Exp-Noah-MP, Exp-PX and Exp-SSiB respectively. The initial and boundary conditions for the WRF model simulations were provided by the National Centers for Environmental Prediction Final (NCEP-FNL) Operational Global Analysis data. The ERA-Interim reanalysis (ERAI), the GHCN-CAMS and the CRU gridded data were used to comprehensively evaluate the WRF simulations. Compared with the reanalysis and observational data, the WRF model can reasonably reproduce the spatial patterns of summer mean 2-m temperature, precipitation, and large- scale atmospheric circulation. The simulations, however, are sensitive to the option of land surface scheme. The performance of Exp-CLM4 and Exp-SSiB are better than that of Exp-Noah-MP and Exp-PX assessed by Multivariable Integrated Evaluation (MVIE) method. To comprehensively understand the dynamic and physical mechanisms for the WRF model’s sensitivity to land surface schemes, the differences in the surface energy balance between Ave-CLM4-SSiB (the ensemble average of Exp-CLM4 and Exp-SSiB) and Ave-NoanMP-PX (the ensemble average of Exp-Noah-MP and Exp-PX) are analyzed in detail. The results demonstrate that the sensible and latent heat fluxes are respectively lower by 30.42 W·m−2 and higher by 14.86 W·m−2 in Ave-CLM4-SSiB than that in Ave-NoahMP-PX. As a result, large differences in geopotential height occur over the simulation domain. The simulated wind fields are subsequently influenced by the geostrophic adjustment process, thus the simulations of 2-m temperature, surface skin temperature and precipitation are respectively lower by about 2.08 ℃, 2.23 ℃ and 18.56 mm·month−1 in Ave-CLM4-SSiB than that in Ave-NoahMP-PX over Central Asia continent.

scholarly journals Multi-objective calibration of the land surface scheme TERRA/LM using LITFASS-2003 data

2005 ◽  
Vol 9 (6) ◽  
pp. 586-596 ◽  
Author(s):  
K.-P. Johnsen ◽  
H.-T. Mengelkamp ◽  
S. Huneke
Keyword(s):  
Heat Flux ◽  
Latent Heat ◽  
Land Surface ◽  
Vegetation Type ◽  
Sensible Heat Flux ◽  
Heat Fluxes ◽  
Land Surface Scheme ◽  
Multi Objective ◽  
Long Term Study ◽  
Surface Scheme

Abstract. The turbulent sensible and latent heat fluxes simulated in the operational weather forecast model LM have been checked with data from the field experiment LITFASS 2003 (Lindenberg Inhomogeneous Terrain - Fluxes between Atmosphere and Surface: a Long-term Study) using both single site measurements and grid box aggregated fluxes. SCE-UA (single objective) and MOSCEM-UA (multi-objective) approaches were applied to calibrate the land-surface scheme TERRA/LM for 11 single sites and for the aggregated fluxes. A large variation is seen among the parameter sets found by calibration but no typical classification according to vegetation type is obvious. This is attributed to the calibrated parameter sets correcting for model deficiencies and data errors rather than describing the physical characteristics of the measurement site. The measured fluxes were combined into a time series of aggregated fluxes by the tile method. Calibration of TERRA/LM with respect to the averaged fluxes resulted in a range of parameter sets which all simulated the area-averaged fluxes in much better agreement with the observed fluxes than the standard parameter set of the operational model. A modified Nash-Sutcliffe measure as a coincidence criterion fell from 0.3 to a range between 0.15 and 0.28 for the latent heat flux and from 0.43 to between 0.26 and 0.36 for the sensible heat flux when the calibrated parameter sets were used instead of the standard parameters.

scholarly journals A Process-Oriented Small Lake Scheme for Coupled Climate Modeling Applications

2012 ◽  
Vol 13 (6) ◽  
pp. 1911-1924 ◽  
Author(s):  
Murray D. MacKay
Keyword(s):  
Heat Flux ◽  
Latent Heat ◽  
Land Surface ◽  
Global Climate Model ◽  
Sensible Heat Flux ◽  
Open Water ◽  
Surface Mixed Layer ◽  
Linear Temperature ◽  
Land Surface Scheme ◽  
Surface Scheme

Abstract A one-dimensional dynamic lake model is presented as a candidate for simulating small unresolved lakes within the land surface scheme of a regional or global climate model. This model is based largely on well-established process algorithms with some exceptions. The complete nonlinear surface energy balance is computed in a skin layer of arbitrary thickness in order to ensure rapid response times with the atmosphere. Turbulent mixing in the surface mixed layer is achieved through stirring and buoyancy production as well as shear production along the diurnal thermocline. The net effect of Kelvin–Helmholtz instability on thermocline structure is grossly accounted for by computing a linear temperature profile within a thermocline layer. The energetics of billowing is not considered; however, a significant thermocline leakage term is included. The model has been incorporated into the Canadian Land Surface Scheme and used to estimate regional turbulent sensible and latent heat fluxes over the Experimental Lakes Area in the boreal forest of northwestern Ontario—an area about 30% lake covered. It is demonstrated that the presence of open water has a significant effect on the net flux exchange with the atmosphere in this region. Sensible heat flux to the atmosphere is suppressed during the summer stratified period but enhanced in the fall, resulting in an increased accumulation of about 5% by the end of the open water season due to the presence of lakes. Turbulent latent heat flux to the atmosphere is more enhanced during autumn, with a final accumulation about 24% larger.

scholarly journals Soil Surface Energy and Water Budgets during a Monsoon Season in Korea

2009 ◽  
Vol 10 (6) ◽  
pp. 1379-1396 ◽  
Author(s):  
Claudio Cassardo ◽  
Seon Ki Park ◽  
Bindu Malla Thakuri ◽  
Daniela Priolo ◽  
Ying Zhang
Keyword(s):  
Heat Flux ◽  
Surface Layer ◽  
Latent Heat ◽  
Land Surface ◽  
Process Model ◽  
Large Scale ◽  
Sensible Heat Flux ◽  
Land Surface Scheme ◽  
Soil Temperatures ◽  
Surface Scheme

Abstract In this study, attention has been focused on the climatology of some variables linked to the turbulent exchanges of heat and water vapor in the surface layer during a summer monsoon in Korea. In particular, the turbulent fluxes of sensible and latent heat, the hydrologic budget, and the soil temperatures and moistures have been analyzed. At large scale, because the measurements of those data are not only fragmentary and exiguously available but also infeasible for the execution of climatologic analyses, the outputs of a land surface scheme have been used as surrogate of observations to analyze surface layer processes [this idea is based on the methodology Climatology of Parameters at the Surface (CLIPS)] in the Korean monsoonal climate. Analyses have been made for the summer of 2005. As a land surface scheme, the land surface process model (LSPM) developed at the University of Torino, Italy, has been employed, along with the data collected from 635 Korean meteorological stations. The LSPM predictions showed good agreement with selected observations of soil temperature. Major results show that, during the rainfall season, soil moisture in the first tenths of centimeters frequently exceeds the field capacity, whereas most of the rainfall is “lost” as surface runoff. Evapotranspiration is the dominant component of the energy budget, sometimes even exceeding net radiation, especially during the short periods between the precipitation events; in these periods, daily mean soil temperatures are about 28°C or even more. The Gyeonggi-do region, the metropolitan area surrounding Seoul, shows some particularities when compared with the neighboring regions: solar radiation and precipitations are lower, causing high values of sensible heat flux and soil temperatures, and lower values of latent heat flux and soil moistures.

Examining Terrain Effects on an Upstate New York Tornado Event Utilizing a High-Resolution Model Simulation

2021 ◽  
Author(s):  
Luke J. LeBel ◽  
Brian H. Tang ◽  
Ross A. Lazear
Keyword(s):  
New York ◽  
High Resolution ◽  
Wind Shear ◽  
Model Simulation ◽  
Wrf Model ◽  
Severe Weather ◽  
Streamwise Vorticity ◽  
Low Level ◽  
Severe Convection ◽  
The Impact

AbstractThe complex terrain at the intersection of the Mohawk and Hudson valleys of New York has an impact on the development and evolution of severe convection in the region. Specifically, previous research has concluded that terrain-channeled flow in the Mohawk and Hudson valleys likely contributes to increased low-level wind shear and instability in the valleys during severe weather events such as the historic 31 May 1998 event that produced a strong (F3) tornado in Mechanicville, New York.The goal of this study is to further examine the impact of terrain channeling on severe convection by analyzing a high-resolution WRF model simulation of the 31 May 1998 event. Results from the simulation suggest that terrain-channeled flow resulted in the localized formation of an enhanced low-level moisture gradient, resembling a dryline, at the intersection of the Mohawk and Hudson valleys. East of this boundary, the environment was characterized by stronger low-level wind shear and greater low-level moisture and instability, increasing tornadogenesis potential. A simulated supercell intensified after crossing the boundary, as the larger instability and streamwise vorticity of the low-level inflow was ingested into the supercell updraft. These results suggest that terrain can have a key role in producing mesoscale inhomogeneities that impact the evolution of severe convection. Recognition of these terrain-induced boundaries may help in anticipating where the risk of severe weather may be locally enhanced.

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