Geography Reference
In-Depth Information
pattern (including the horizontal direction and the vertical direction), and provides
initial and boundary condition file for the model.
In WRF model, the original land use data come from the global 24 types of land
use and land cover classified by United States Geographical Survey land use
systems (USGS). Each land use types have different roughness, albedo, and other
parameters, affecting the flow of meteorological fields, precipitation, temperature,
or temperature.
In WRF simulation, each grid point has a land cover type based on the land
cover dataset being used for the model run. The properties (surface albedo, surface
emissivity, moisture availability, surface roughness length) of each land cover type
depend on the land surface model used in the WRF run. The land-surface model is
the component that takes care of the processes involving land-surface interactions.
For the WRF runs, the parameterization scheme of physical processes in the model
should be set, USGS classification data set need to be used to specify land cover
types and their properties.
The interactions between the atmosphere and other earth system components,
which are important drivers of regional climate, are not well explained in most
RCMs models. Although more and more of these interactions are now represented
in GCMs, global models lack the spatial resolution to represent regional-scale
processes and feedbacks. Biases in simulating regional precipitation, for example,
can have far-reaching consequences in fully coupled models of the climate system,
because water integrates across the physical, biological, and chemical components.
Therefore, WRF is strongly recommended to address a wide range of science
questions specific to regional-scale processes, and forcing and response. Examples
include interactive coupling of the RCM with sea ice and ocean models to rep-
resent air-sea interactions; chemistry and aerosol models, including dust, to rep-
resent chemistry-aerosol-cloud-radiation feedbacks; and marine and terrestrial
ecosystem models to represent biogeochemical cycling processes. Additionally,
developing more comprehensive treatments of land surface and hydrological
processes, including river routing, subsurface flow, lake, land use, fires, and land
ice, will enable a more dynamic representation of land-atmosphere feedbacks. It is
noted that some development efforts are already underway in the framework of the
Community Land Model (CLM) and Noah land surface model that have been
implemented in WRF. Building data assimilation capabilities for the coupled
model will enable the development of regional analyses of the Earth system; an
example is an ocean and land data assimilation system. Finally, to facilitate model
coupling, participants recommended accelerating the transition of WRF to the
Earth System Modeling Framework (ESMF) (Tolstoy et al.
2004
).
