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investigation. A review of different approaches to regional climate modeling was recently provided by Laprise (2008) . Because of their limited area, RCMs require time-dependent lateral boundary conditions (LBCs). Low-resolution reanalyses or GCM simulations usually provide the LBCs to RCMs. Recent studies showed that, when driven by realistic (appropriate and accurate) boundary conditions, RCMs are capable of capturing the overall observed regional climate evolution and can add realistic higher
investigation. A review of different approaches to regional climate modeling was recently provided by Laprise (2008) . Because of their limited area, RCMs require time-dependent lateral boundary conditions (LBCs). Low-resolution reanalyses or GCM simulations usually provide the LBCs to RCMs. Recent studies showed that, when driven by realistic (appropriate and accurate) boundary conditions, RCMs are capable of capturing the overall observed regional climate evolution and can add realistic higher
. (2011) studied PMP for a catchment in California and applied a regional-scale high-resolution physical atmospheric model. Other studies have also applied NWP-based methods to estimate PMP, where the approach is based on physical maximization of a historical extreme rainstorm. Ishida et al. (2015a) alters boundary and initial conditions to maximize precipitation over targeted catchments. Chen and Hossain (2018) pointed out that there seems to have emerged a consensus that using a physical
. (2011) studied PMP for a catchment in California and applied a regional-scale high-resolution physical atmospheric model. Other studies have also applied NWP-based methods to estimate PMP, where the approach is based on physical maximization of a historical extreme rainstorm. Ishida et al. (2015a) alters boundary and initial conditions to maximize precipitation over targeted catchments. Chen and Hossain (2018) pointed out that there seems to have emerged a consensus that using a physical
) motivate the use of improved subsurface storage schemes. Choice of soil hydraulic parameterizations are also important in mesoscale meteorological models; Braun and Schädler (2005) compared several models, finding that the soil hydraulic parameterizations based on van Genuchten (1980) performed better than Clapp–Hornberger ( Clapp and Hornberger 1978 ; Cosby et al. 1984 ) models. Free-draining boundary conditions, in which water may freely drain at the rate of conductivity of the lowest node or
) motivate the use of improved subsurface storage schemes. Choice of soil hydraulic parameterizations are also important in mesoscale meteorological models; Braun and Schädler (2005) compared several models, finding that the soil hydraulic parameterizations based on van Genuchten (1980) performed better than Clapp–Hornberger ( Clapp and Hornberger 1978 ; Cosby et al. 1984 ) models. Free-draining boundary conditions, in which water may freely drain at the rate of conductivity of the lowest node or
, with fully compressible, nonhydrostatic equations solved in the dynamical core. WRF simulations are set up with two groups of initial and boundary conditions. One is driven by the 6-hourly NCEP Global Forecasting System (GFS) analyses on a 1° grid with 27 hydroclimate variables ( NCEP 2000 ) at the lateral boundaries of the WRF outer domain, abbreviated as WRF_NCEP in this paper. The other group of WRF simulations is abbreviated as WRF_VRCESM and employs the intermediate files generated from the 6
, with fully compressible, nonhydrostatic equations solved in the dynamical core. WRF simulations are set up with two groups of initial and boundary conditions. One is driven by the 6-hourly NCEP Global Forecasting System (GFS) analyses on a 1° grid with 27 hydroclimate variables ( NCEP 2000 ) at the lateral boundaries of the WRF outer domain, abbreviated as WRF_NCEP in this paper. The other group of WRF simulations is abbreviated as WRF_VRCESM and employs the intermediate files generated from the 6
autonomy was sought to allow land–atmosphere coupling effects to develop. Though the lateral boundary conditions of the model’s rather modestly sized outer domain are expected to constrain the large-scale circulation, the SST perturbation may have caused circulation changes (e.g., Graff and Lacasce 2014 ). However, this has not been the topic of this study. Similarly, evaluating possible remote or large-scale effects of the vegetation or snow cover change (e.g., Xu and Dirmeyer 2011 ; Orsolini et al
autonomy was sought to allow land–atmosphere coupling effects to develop. Though the lateral boundary conditions of the model’s rather modestly sized outer domain are expected to constrain the large-scale circulation, the SST perturbation may have caused circulation changes (e.g., Graff and Lacasce 2014 ). However, this has not been the topic of this study. Similarly, evaluating possible remote or large-scale effects of the vegetation or snow cover change (e.g., Xu and Dirmeyer 2011 ; Orsolini et al
. On top of that, the boundary layer dynamics are themselves dependent on the evaporative fraction, so that the nonevaporative term is not really disentangled from the evaporative one. To resolve this issue, the boundary layer dynamics need to be taken into account in the relative humidity tendency equation. The main objective of this work is to explicitly delineate the conditions leading to either dry or wet soil advantage in the triggering of moist convection based on surface or atmospheric
. On top of that, the boundary layer dynamics are themselves dependent on the evaporative fraction, so that the nonevaporative term is not really disentangled from the evaporative one. To resolve this issue, the boundary layer dynamics need to be taken into account in the relative humidity tendency equation. The main objective of this work is to explicitly delineate the conditions leading to either dry or wet soil advantage in the triggering of moist convection based on surface or atmospheric
constant or statistically stationary forcings while the historical run reproduces observed volcanic events, aerosol emissions, atmospheric composition trends, and boundary conditions. For the estimation of correlations and interannual variability, linear trends are removed from the data for each month along with the mean annual cycle. This ensures the estimates of temporal standard deviations are not dominated by trends, but reflect the shorter-term interannual variations of importance to land
constant or statistically stationary forcings while the historical run reproduces observed volcanic events, aerosol emissions, atmospheric composition trends, and boundary conditions. For the estimation of correlations and interannual variability, linear trends are removed from the data for each month along with the mean annual cycle. This ensures the estimates of temporal standard deviations are not dominated by trends, but reflect the shorter-term interannual variations of importance to land
Physics Regional Climate Model version 3 (RegCM3; RCM3 in the archive), and the Experimental Climate Prediction Center's Regional Spectral Model (ECP2 in the archive). All models used approximately 0.5° horizontal resolution. Atmospheric boundary conditions, sea surface temperatures (SSTs), and ocean ice fractions came from the reanalysis ( Kanamitsu et al. 2002 ) produced by the National Centers for Environmental Prediction (NCEP) and the U.S. Department of Energy (DOE). Except for the northern side
Physics Regional Climate Model version 3 (RegCM3; RCM3 in the archive), and the Experimental Climate Prediction Center's Regional Spectral Model (ECP2 in the archive). All models used approximately 0.5° horizontal resolution. Atmospheric boundary conditions, sea surface temperatures (SSTs), and ocean ice fractions came from the reanalysis ( Kanamitsu et al. 2002 ) produced by the National Centers for Environmental Prediction (NCEP) and the U.S. Department of Energy (DOE). Except for the northern side
revealed specific impacts and improvements in coupled models as a result of improved specification of the land initial condition. Kumar et al. (2008) found significant differences in prediction of fluxes, boundary layer structure, and temperature and humidity, and improvements in precipitation forecasts when using a multiyear spinup versus using the default WRF land surface initialization. Similarly, Case et al. (2008) showed that spun-up initial conditions led to improved sea breeze circulation
revealed specific impacts and improvements in coupled models as a result of improved specification of the land initial condition. Kumar et al. (2008) found significant differences in prediction of fluxes, boundary layer structure, and temperature and humidity, and improvements in precipitation forecasts when using a multiyear spinup versus using the default WRF land surface initialization. Similarly, Case et al. (2008) showed that spun-up initial conditions led to improved sea breeze circulation
vertical diffusion and the 2D Smagorinsky scheme for horizontal diffusion, and 4) the Noah LSM. Cumulus parameterization was not used for any of these domains since even the largest grid size is less than 10 km. In this study, one-way nesting is used. The initial and boundary conditions are taken from the North American Regional Reanalysis (NARR). The simulations all started at 0000 UTC 21 July 2008 and ended at 0000 UTC on 26 July 2008, with an output frequency of 1 h. The time steps for the three
vertical diffusion and the 2D Smagorinsky scheme for horizontal diffusion, and 4) the Noah LSM. Cumulus parameterization was not used for any of these domains since even the largest grid size is less than 10 km. In this study, one-way nesting is used. The initial and boundary conditions are taken from the North American Regional Reanalysis (NARR). The simulations all started at 0000 UTC 21 July 2008 and ended at 0000 UTC on 26 July 2008, with an output frequency of 1 h. The time steps for the three
