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WRF short-term simulation is severely affected by initial condition. Therefore, if your input data are different and the difference between them is large, then your WRF results could quite different, too.
By short-term simulation, we usually refer to simulation over a few days, for example, 3-5 day forecast.
WRF resolution can be within the range from tens of kilometers to tens of meters. For large eddy simulation, it can go to as high as 30-100m. For urban study, if you focus on urban heat island, then probably 1km resolution is fine. if you want to explore eddy structure in street valleys, very high resolution like 30-50m is necessary, This is my personal opinion. please refer to the literature for more details,
Many thanks for your detailed reply. I still have one point to ask: You mentioned "I would expect slight changes in the model results if you run WRF with different map projections". Did you mean that map projections indicate landuse or geographical static data instead of Lambert?
Map projection refers to the specific map projection we implement when running WRF, e.g., lambert, mercator, lat-lon, etc. Different map projections may lead to slightly different distortion of the grid, and these slight differences will be reflected in the model output. This is why when you run WRF over the same domain but with different map projections, your results are not identical.