Update geojson and mesh parameters

Use a custom geojson that extends the gutter where we expect many
runs to predict margin advance. Also update mesh parameters for a
high resolution mesh that uses only bed topograhpy to set cell spacing,
and fix bug that was setting cell spacing to the maximum value
outside of the ice mask.

Author: trhille

compass/landice/mesh.py

@@ -372,7 +372,7 @@ def set_cell_width(self, section_name, thk, bed=None, vx=None, vy=None,
     # that distance.
     if dist_to_edge is not None:
         mask = np.logical_and(
-            thk == 0.0, dist_to_edge > (3. * cull_distance))
+            thk == 0.0, dist_to_edge > (35. * np.abs(cull_distance)))
         logger.info('Setting cell_width in outer regions to max_spac '
                     f'for {mask.sum()} cells')
         cell_width[mask] = max_spac

compass/landice/tests/humboldt/Humboldt.geojson

@@ -13,13 +13,13 @@ y_max = -860000.
 # distance from ice margin to cull (km).
 # Set to a value <= 0 if you do not want
 # to cull based on distance from margin.
-cull_distance = 5.0
+cull_distance = -1.0
 
 # mesh density parameters
 # minimum cell spacing (meters)
 min_spac = 1.e3
 # maximum cell spacing (meters)
-max_spac = 1.e4
+max_spac = 2.5e3
 # log10 of max speed (m/yr) for cell spacing
 high_log_speed = 2.5
 # log10 of min speed (m/yr) for cell spacing
@@ -29,18 +29,18 @@ high_dist = 1.e5
 # distance within which cell spacing = min_spac (meters)
 low_dist = 1.e4
 # distance at which bed topography has no effect
-high_dist_bed = 1.e5
+high_dist_bed = 8.e4
 # distance within which bed topography has maximum effect
-low_dist_bed = 5.e4
+low_dist_bed = 7.e4
 # Bed elev beneath which cell spacing is minimized
 low_bed = 50.0
 # Bed elev above which cell spacing is maximized
 high_bed = 100.0
 
 # mesh density functions
-use_speed = True
+use_speed = False
 use_dist_to_grounding_line = False
-use_dist_to_edge = True
+use_dist_to_edge = False
 use_bed = True
 
 [greenland]