def run_model(grid, orography):
"Run the PISM implementation of the model to compare to the Python version."
model = PISM.AtmosphereOrographicPrecipitation(
grid, PISM.AtmosphereUniform(grid))
geometry = PISM.Geometry(grid)
with PISM.vec.Access(nocomm=geometry.ice_thickness):
for i, j in grid.points():
geometry.ice_thickness[i, j] = orography[j, i]
geometry.bed_elevation.set(0.0)
geometry.sea_level_elevation.set(0.0)
geometry.ice_area_specific_volume.set(0.0)
# compute surface elevation from ice thickness and bed elevation
geometry.ensure_consistency(0)
model.init(geometry)
model.update(geometry, 0, 1)
config = PISM.Context().config
water_density = config.get_number("constants.fresh_water.density")
# convert from kg / (m^2 s) to mm/s
return model.mean_precipitation().numpy() / (1e-3 * water_density)
def input_file(filename):
ctx = PISM.Context()
grid = PISM.IceGrid.FromFile(ctx.ctx, filename, ["topg"], PISM.CELL_CENTER)
geometry = PISM.Geometry(grid)
geometry.bed_elevation.regrid(filename)
geometry.ice_thickness.set(0.0)
geometry.sea_level_elevation.set(0.0)
geometry.ensure_consistency(0.0)
model = PISM.AtmosphereOrographicPrecipitation(
grid, PISM.AtmosphereUniform(grid))
model.init(geometry)
model.update(geometry, 0, 1)
model.mean_precipitation().dump(config.get_string("output.file_name"))
def synthetic_geometry(grid, orography):
config = PISM.Context().config
# set wind speed and direction
config.set_number("atmosphere.orographic_precipitation.wind_speed", 15.0)
config.set_number("atmosphere.orographic_precipitation.wind_direction",
270)
config.set_number("atmosphere.orographic_precipitation.conversion_time",
1000.0)
config.set_number("atmosphere.orographic_precipitation.fallout_time",
1000.0)
config.set_number(
"atmosphere.orographic_precipitation.water_vapor_scale_height", 2500.0)
config.set_number(
"atmosphere.orographic_precipitation.moist_stability_frequency", 0.005)
config.set_number("atmosphere.orographic_precipitation.reference_density",
7.4e-3)
# eliminate the effect of the Coriolis force
config.set_number("atmosphere.orographic_precipitation.coriolis_latitude",
0.0)
model = PISM.AtmosphereOrographicPrecipitation(
grid, PISM.AtmosphereUniform(grid))
geometry = PISM.Geometry(grid)
with PISM.vec.Access(nocomm=geometry.ice_thickness):
for i, j in grid.points():
geometry.ice_thickness[i, j] = orography[j, i]
geometry.bed_elevation.set(0.0)
geometry.sea_level_elevation.set(0.0)
geometry.ice_area_specific_volume.set(0.0)
# compute surface elevation from ice thickness and bed elevation
geometry.ensure_consistency(0)
model.init(geometry)
model.update(geometry, 0, 1)
# convert from mm/s to mm/hour
return model.mean_precipitation().numpy() * 3600
