Make third-order space and time default for convergence tests

Make third-order space and time default for convergence tests, since
these aren't very useful for first-order.

Author: trhille

compass/landice/tests/mesh_convergence/halfar/namelist.forward

@@ -1,3 +1,9 @@
 config_velocity_solver = 'sia'
-config_thickness_advection = 'fo'
-config_tracer_advection = 'fo'
+config_thickness_advection = 'fct'
+config_tracer_advection = 'fct'
+config_horiz_tracer_adv_order = 3
+config_advection_coef_3rd_order = 1.0
+config_start_time = '0001-01-01_00:00:00'
+config_time_integration = 'runge_kutta'
+config_rk_order = 3
+config_rk3_stages = 3

compass/landice/tests/mesh_convergence/horizontal_advection/namelist.forward

@@ -0,0 +1,10 @@
+config_velocity_solver = 'none'
+config_unrealistic_velocity = 1.0e36
+config_thickness_advection = 'fct'
+config_horiz_tracer_adv_order = 3
+config_advection_coef_3rd_order = 1.0
+config_tracer_advection = 'fct'
+config_start_time = '0001-01-01_00:00:00'
+config_time_integration = 'runge_kutta'
+config_rk_order = 3
+config_rk3_stages = 3

compass/landice/tests/mesh_convergence/horizontal_advection_thickness/namelist.forward

@@ -1,5 +1,10 @@
 config_velocity_solver = 'none'
 config_unrealistic_velocity = 1.0e36
-config_thickness_advection = 'fo'
+config_thickness_advection = 'fct'
+config_horiz_tracer_adv_order = 3
+config_advection_coef_3rd_order = 1.0
 config_tracer_advection = 'none'
 config_start_time = '0001-01-01_00:00:00'
+config_time_integration = 'runge_kutta'
+config_rk_order = 3
+config_rk3_stages = 3