diff --git a/.gitignore b/.gitignore
index 86c03f9..3ee2607 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,6 +6,7 @@
 *.jld2
 *.nc
 *.vscode
+*.mp4
 /Manifest.toml
 /deps/deps.jl
 /docs/Manifest.toml
diff --git a/examples/single_interface_periodic_linear_background.jl b/examples/single_interface_periodic_linear_background.jl
new file mode 100644
index 0000000..cab3fa6
--- /dev/null
+++ b/examples/single_interface_periodic_linear_background.jl
@@ -0,0 +1,35 @@
+using StaircaseShenanigans
+
+architecture = CPU() # or GPU()
+diffusivities = (ν = 1e-5, κ = (S = 1e-7, T = 1e-5))
+domain_extent = (Lx = 0.1, Ly = 0.1, Lz = -1.0)
+resolution = (Nx = 5, Ny = 5, Nz = 50)
+eos = CustomLinearEquationOfState(-0.5, 34.6)
+model_setup = (;architecture, diffusivities, domain_extent, resolution, eos)
+
+## Initial conditions
+depth_of_interface = -0.5
+salinity = [34.56, 34.70]
+temperature = [-1.5, 0.5]
+interface_ics = PeriodoicSingleInterfaceICs(eos, depth_of_interface, salinity, temperature,
+                                            BackgroundLinear())
+tracer_noise = TracerNoise(1e-6, 1e-6)
+
+## setup model
+sdns = StaircaseDNS(model_setup, interface_ics, tracer_noise)
+
+## Build simulation
+Δt = 1e-1
+stop_time = 4 * 60 * 60 # seconds
+save_schedule = 30  # seconds
+output_path = joinpath(@__DIR__, "output_linear_background")
+simulation = SDNS_simulation_setup(sdns, stop_time, save_computed_output!,
+                                    save_vertical_velocities!;
+                                    Δt, save_schedule,
+                                    output_path, max_Δt = 5)
+## Run
+run!(simulation)
+
+## Compute density ratio
+compute_R_ρ!(simulation.output_writers[:computed_output].filepath,
+             simulation.output_writers[:tracers].filepath, eos)
diff --git a/examples/single_interface_periodic.jl b/examples/single_interface_periodic_tanh_background.jl
similarity index 81%
rename from examples/single_interface_periodic.jl
rename to examples/single_interface_periodic_tanh_background.jl
index fa0a51e..7af175e 100644
--- a/examples/single_interface_periodic.jl
+++ b/examples/single_interface_periodic_tanh_background.jl
@@ -9,9 +9,10 @@ model_setup = (;architecture, diffusivities, domain_extent, resolution, eos)
 
 ## Initial conditions
 depth_of_interface = -0.5
-salinity = [34.58, 34.70]
+salinity = [34.56, 34.70]
 temperature = [-1.5, 0.5]
-interface_ics = PeriodoicSingleInterfaceICs(eos, depth_of_interface, salinity, temperature, BackgroundTanh(tanh_background, 100, NamedTuple()))
+interface_ics = PeriodoicSingleInterfaceICs(eos, depth_of_interface, salinity, temperature,
+                                            BackgroundTanh())
 tracer_noise = TracerNoise(1e-6, 1e-6)
 
 ## setup model
@@ -19,9 +20,9 @@ sdns = StaircaseDNS(model_setup, interface_ics, tracer_noise)
 
 ## Build simulation
 Δt = 1e-1
-stop_time = 200 * 60 # seconds
-save_schedule = 10  # seconds
-output_path = joinpath(@__DIR__, "output")
+stop_time = 4 * 60 * 60 # seconds
+save_schedule = 30  # seconds
+output_path = joinpath(@__DIR__, "output_tanh_background")
 simulation = SDNS_simulation_setup(sdns, stop_time, save_computed_output!,
                                     save_vertical_velocities!;
                                     Δt, save_schedule,