The CWRF is developed as a climate extension of the Weather Research and Forecasting model (WRF) by incorporating numerous improvements in the representation of physical processes and integration of external (top, surface, lateral) forcings that are crucial to climate scales, including interactions between land, atmosphere, and ocean; convection and microphysics; and cloud, aerosol, and radiation; and system consistency throughout all process modules. This extension inherits all WRF functionalities for numerical weather prediction while enhancing the capability for climate modeling. As such, CWRF can be applied seamlessly to weather forecast and climate prediction. The CWRF is built with a comprehensive ensemble of alternative parameterization schemes for each of the key physical processes, including surface (land, ocean), planetary boundary layer, cumulus (deep, shallow), microphysics, cloud, aerosol, and radiation, and their interactions. This facilitates the use of an optimized physics ensemble approach to improve weather or climate prediction along with a reliable uncertainty estimate. The CWRF also emphasizes the societal service capability to provide impactrelevant information by coupling with detailed models of terrestrial hydrology, coastal ocean, crop growth, air quality, and a recently expanded interactive water quality and ecosystem model. This study provides a general CWRF description and basic skill evaluation based on a continuous integration for the period 1979– 2009 as compared with that of WRF, using a 30-km grid spacing over a domain that includes the contiguous United States plus southern Canada and northern Mexico. In addition to advantages of greater application capability, CWRF improves performance in radiation and terrestrial hydrology over WRF and other regional models. Precipitation simulation, however, remains a challenge for all of the tested models.
[1] Subgrid variability of subsurface moisture flux transport is strongly influenced by the local variation of topographic attributes, such as elevation, slope, and curvature. A threedimensional volume-averaged soil moisture transport (VAST) model is developed to incorporate these effects using the volume-averaged Richards equation. The smallperturbation approach is used to decompose the equation into mean and fluctuation, which are then averaged over the model grid box. This formulation explicitly incorporates the variability of moisture flux due to subgrid variation of topographic attributes. The model is independent of scale, but the parameters need to be estimated at the model scale. It is demonstrated that the flux contribution from the subgrid variability can be comparable to that of mean flux, particularly under drier moisture conditions. This formulation can be substituted for subsurface moisture transport schemes in most existing land surface models.Citation: Choi, H. I., P. Kumar, and X.-Z. Liang (2007), Three-dimensional volume-averaged soil moisture transport model with a scalable parameterization of subgrid topographic variability, Water Resour. Res., 43, W04414,
The sedimentation and evolutionary history of the Gyeongsang Basin, and their implications for plate tectonics are reviewed based mainly on sedimentological work on the Gyeongsang strata, and the regional geology of the Japanese Islands. During the Cretaceous, E Asia was characterized by an Andean-type continental margin formed by subduction of the Kula plate and Kula–Pacific ridge. The marginal zone was subjected to precursory extensional tectonism of the magmatic arc so that fault-bounded continental depressions developed, including the proto-Gyeongsang Basin. The Gyeongsang strata (about 9,000 m thick) consist in ascending order of the Sindong, the Hayang with volcanic' stics, and volcanic Yuchon Groups. During the Sindong period extensional tectonism prevailed a the proto-Gyeongsang Basin was a graben occupied by alluvial fan, fluvial plain and lake environments from the margins to the centre of the basin. Streams flowed from the upthrown lip areas to the centre. Alluvial fans expanded periodically with rejuvenation of fault activity, while the fluvial plaid/lake boundary shifted in response to climatic changes. During the Hayang period the faults were no longer active and consequently the basin extended beyond them (probably by back faulting). The water level of the lake(s) at the basin centre fluctuated with changes of the evaporation/precipitation ratio. During parts of the period, the marginal fluvial plain was drained by ephemeral streams which disappeared before reaching the lake(s), depositing fluvial sequences lacking channel sandstones. Localized volcanism formed volcanic terrains and supplied pyroclastics: this volcanism was climactic during the Yuchon period and terminated the sedimentation. Granitic plutons intruded all the Gyeongsang strata at about the end of the cretaceous.
This study addresses several deficiencies in the existing formulations for terrestrial hydrologic processes in the Common Land Model (CLM) and presents improved solutions, focusing on runoff prediction. In particular, this paper has 1) incorporated a realistic geographic distribution of bedrock depth to improve estimates of the actual soil water capacity; 2) replaced an equilibrium approximation with a dynamic prediction of the water table to produce more reasonable variations of the saturated zone depth; 3) used an exponential decay function with soil depth for the saturated hydraulic conductivity to consider the effect of macropores near the ground surface; 4) formulated an effective hydraulic conductivity of the liquid part at the frozen soil interface and imposed a maximum surface infiltration limit to eliminate numerically generated negative or excessive soil moisture solution; and 5) examined an additional contribution to subsurface runoff from saturation lateral runoff or baseflow controlled by topography. To assess the performance of these modifications, runoff results from a set of offline simulations are validated at a catchment-scaled study domain around the Ohio Valley region. Together, these new schemes enable the CLM to capture well the major characteristics of the observed total runoff variations. The improvement is especially significant at peak discharges under high flow conditions.
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