NumericalEarth · simone-silvestri · May 12, 2026 · Apr 15, 2026 · Apr 15, 2026 · Apr 15, 2026
diff --git a/Project.toml b/Project.toml
@@ -60,7 +60,7 @@ ArchGDAL = "0.10"
 Breeze = "0.4"
 CDSAPI = "2.2.1"
 CFTime = "0.1, 0.2"
-ClimaSeaIce = "0.4.4, 0.5"
+ClimaSeaIce = "0.5"
 CondaPkg = "0.2.33"
 CopernicusMarine = "0.1.1"
 CubedSphere = "0.3.4"

diff --git a/docs/Project.toml b/docs/Project.toml
@@ -22,7 +22,6 @@ Suppressor = "fd094767-a336-5f1f-9728-57cf17d0bbfb"
 XESMF = "2e0b0046-e7a1-486f-88de-807ee8ffabe5"
 
 [sources]
-Breeze = {rev = "main", url = "https://github.com/NumericalEarth/Breeze.jl/"}
 NumericalEarth = {path = ".."}
 
 [compat]
@@ -32,3 +31,4 @@ CUDA = "~6.0"
 Documenter = "1"
 DocumenterCitations = "1.3"
 Literate = "2.2"
+ClimaSeaIce = "0.5.0"
diff --git a/docs/src/NumericalEarth.bib b/docs/src/NumericalEarth.bib
@@ -84,9 +84,9 @@ @article{holland1999modeling
   doi={10.1175/1520-0485(1999)029<1787:MTIOIA>2.0.CO;2}
 }
 
-@article{hieronymus2021comparison,
-  title={A comparison of ocean-ice flux parametrizations},
-  author={Hieronymus, Magnus and Holtermann, Peter and Gr{\"a}we, Ulf and Burchard, Hans},
+@article{shi2021sensitivity,
+  title={Sensitivity of {Northern Hemisphere} climate to ice--ocean interface heat flux parameterizations},
+  author={Shi, Xiaoxu and Notz, Dirk and Liu, Jiping and Yang, Hu and Lohmann, Gerrit},
   journal={Geoscientific Model Development},
   volume={14},
   number={8},

diff --git a/docs/src/interface_fluxes.md b/docs/src/interface_fluxes.md
@@ -817,7 +817,7 @@ where:
 - ``\lambda_1, \lambda_2`` are liquidus coefficients
 
 The ratio ``R = \alpha_h / \alpha_s`` (typically around 35) reflects the different molecular diffusivities of heat and
-salt, with heat diffusing faster than salt [hieronymus2021comparison](@citep).
+salt, with heat diffusing faster than salt [shi2021sensitivity](@citep).
 
 ```@example interface_fluxes
 using NumericalEarth.EarthSystemModels: ThreeEquationHeatFlux
@@ -975,4 +975,4 @@ Note: The `ComponentInterfaces` call above is illustrative; it requires fully co
 
 The implementations follow:
 - [holland1999modeling](@citet): foundational three-equation model for ice shelf-ocean interaction
-- [hieronymus2021comparison](@citet): comparison of different ocean-ice flux parameterizations
+- [shi2021sensitivity](@citet): sensitivity of Northern Hemisphere climate to ice-ocean interface heat flux parameterizations
diff --git a/ext/NumericalEarthBreezeExt/breeze_atmosphere_interface.jl b/ext/NumericalEarthBreezeExt/breeze_atmosphere_interface.jl
@@ -31,15 +31,15 @@ boundary_layer_height(::BreezeAtmosphere) = 600
 #####
 
 function ComponentExchanger(atmosphere::BreezeAtmosphere, exchange_grid)
-    state = (; u  = Oceananigans.CenterField(exchange_grid),
-               v  = Oceananigans.CenterField(exchange_grid),
-               T  = Oceananigans.CenterField(exchange_grid),
-               p  = Oceananigans.CenterField(exchange_grid),
-               q  = Oceananigans.CenterField(exchange_grid),
+    state = (; u    = Oceananigans.CenterField(exchange_grid),
+               v    = Oceananigans.CenterField(exchange_grid),
+               T    = Oceananigans.CenterField(exchange_grid),
+               p    = Oceananigans.CenterField(exchange_grid),
+               q    = Oceananigans.CenterField(exchange_grid),
                ℐꜜˢʷ = Oceananigans.CenterField(exchange_grid),
                ℐꜜˡʷ = Oceananigans.CenterField(exchange_grid),
-               Jᶜ = Oceananigans.CenterField(exchange_grid),
-               Mp = Oceananigans.CenterField(exchange_grid))
+               Jʳⁿ  = Oceananigans.CenterField(exchange_grid),
+               Jˢⁿ  = Oceananigans.CenterField(exchange_grid))
 
     return ComponentExchanger(state, nothing)
 end
@@ -52,15 +52,15 @@ end
     i, j = @index(Global, NTuple)
 
     @inbounds begin
-        state.u[i, j, 1]  = u[i, j, 1]
-        state.v[i, j, 1]  = v[i, j, 1]
-        state.T[i, j, 1]  = T[i, j, 1]
-        state.q[i, j, 1]  = ρqᵛᵉ[i, j, 1] / ρ₀[i, j, 1]
-        state.p[i, j, 1]  = p₀
+        state.u[i, j, 1]    = u[i, j, 1]
+        state.v[i, j, 1]    = v[i, j, 1]
+        state.T[i, j, 1]    = T[i, j, 1]
+        state.q[i, j, 1]    = ρqᵛᵉ[i, j, 1] / ρ₀[i, j, 1]
+        state.p[i, j, 1]    = p₀
         state.ℐꜜˢʷ[i, j, 1] = 0
         state.ℐꜜˡʷ[i, j, 1] = 0
-        state.Jᶜ[i, j, 1] = 0
-        state.Mp[i, j, 1] = 0
+        state.Jʳⁿ[i, j, 1]  = 0
+        state.Jˢⁿ[i, j, 1]  = 0
     end
 end
 

diff --git a/ext/NumericalEarthSpeedyWeatherExt/speedy_weather_exchanger.jl b/ext/NumericalEarthSpeedyWeatherExt/speedy_weather_exchanger.jl
@@ -31,14 +31,15 @@ function ComponentExchanger(atmosphere::SpeedySimulation, exchange_grid)
     to_atmosphere   = XESMF.Regridder(exchange_grid, spectral_grid)
     regridder = (; to_atmosphere, from_atmosphere)
 
-    state = (; u  = Field{Center, Center, Nothing}(exchange_grid),
-               v  = Field{Center, Center, Nothing}(exchange_grid),
-               T  = Field{Center, Center, Nothing}(exchange_grid),
-               p  = Field{Center, Center, Nothing}(exchange_grid),
-               q  = Field{Center, Center, Nothing}(exchange_grid),
+    state = (; u    = Field{Center, Center, Nothing}(exchange_grid),
+               v    = Field{Center, Center, Nothing}(exchange_grid),
+               T    = Field{Center, Center, Nothing}(exchange_grid),
+               p    = Field{Center, Center, Nothing}(exchange_grid),
+               q    = Field{Center, Center, Nothing}(exchange_grid),
                ℐꜜˢʷ = Field{Center, Center, Nothing}(exchange_grid),
                ℐꜜˡʷ = Field{Center, Center, Nothing}(exchange_grid),
-               Jᶜ = Field{Center, Center, Nothing}(exchange_grid))
+               Jʳⁿ  = Field{Center, Center, Nothing}(exchange_grid),
+               Jˢⁿ  = Field{Center, Center, Nothing}(exchange_grid))
 
     return ComponentExchanger(state, regridder)
 end
@@ -52,14 +53,19 @@ function interpolate_state!(exchanger, exchange_grid, atmos::SpeedySimulation, c
     exchange_state = exchanger.state
     surface_layer  = atmos.model.spectral_grid.nlayers
 
-    ua  = RingGrids.field_view(atmos.variables.grid.u, :, surface_layer).data
-    va  = RingGrids.field_view(atmos.variables.grid.v, :, surface_layer).data
-    Ta  = RingGrids.field_view(atmos.variables.grid.temperature, :, surface_layer).data
-    qa  = RingGrids.field_view(atmos.variables.grid.humidity, :, surface_layer).data
-    pa  = exp.(atmos.variables.grid.pressure.data)
+    ua   = RingGrids.field_view(atmos.variables.grid.u, :, surface_layer).data
+    va   = RingGrids.field_view(atmos.variables.grid.v, :, surface_layer).data
+    Ta   = RingGrids.field_view(atmos.variables.grid.temperature, :, surface_layer).data
+    qa   = RingGrids.field_view(atmos.variables.grid.humidity, :, surface_layer).data
+    pa   = exp.(atmos.variables.grid.pressure.data)
     ℐꜜˢʷ = atmos.variables.parameterizations.surface_shortwave_down.data
     ℐꜜˡʷ = atmos.variables.parameterizations.surface_longwave_down.data
-    Jᶜ  = atmos.variables.parameterizations.rain_rate.data .+ atmos.variables.parameterizations.snow_rate.data
+    Jʳⁿ  = atmos.variables.parameterizations.rain_rate.data
+
+    # `snow_rate` is only registered when SpeedyWeather's large-scale 
+    # condensation parameterization is part of the model
+    Jˢⁿ = haskey(atmos.variables.parameterizations, :snow_rate) ?
+          atmos.variables.parameterizations.snow_rate.data : nothing
 
     regrid!(exchange_state.u,    ua)
     regrid!(exchange_state.v,    va)
@@ -68,7 +74,8 @@ function interpolate_state!(exchanger, exchange_grid, atmos::SpeedySimulation, c
     regrid!(exchange_state.p,    pa)
     regrid!(exchange_state.ℐꜜˢʷ, ℐꜜˢʷ)
     regrid!(exchange_state.ℐꜜˡʷ, ℐꜜˡʷ)
-    regrid!(exchange_state.Jᶜ,   Jᶜ)
+    regrid!(exchange_state.Jʳⁿ,  Jʳⁿ)
+    isnothing(Jˢⁿ) || regrid!(exchange_state.Jˢⁿ, Jˢⁿ)
 
     arch = architecture(exchange_grid)
 
@@ -83,7 +90,8 @@ function interpolate_state!(exchanger, exchange_grid, atmos::SpeedySimulation, c
     fill_halo_regions!(exchange_state.p)
     fill_halo_regions!(exchange_state.ℐꜜˢʷ)
     fill_halo_regions!(exchange_state.ℐꜜˡʷ)
-    fill_halo_regions!(exchange_state.Jᶜ)
+    fill_halo_regions!(exchange_state.Jʳⁿ)
+    isnothing(Jˢⁿ) || fill_halo_regions!(exchange_state.Jˢⁿ)
 
     return nothing
 end

diff --git a/ext/NumericalEarthVerosExt/veros_ocean_simulation.jl b/ext/NumericalEarthVerosExt/veros_ocean_simulation.jl
@@ -29,7 +29,10 @@ Returns a NamedTuple containing package information if successful.
 Also patches Veros's signal handling to work with PythonCall.
 """
 function install_veros()
-    CondaPkg.add("hdf5"; version="<2", channel="conda-forge") # Veros uses hdf5 version < 2. Therefore we pin it to prevent dependency issues
+    # Veros uses hdf5 < 2. The shenanigans in the following two lines 
+    # are necessary to allow loading compatible hdf5 and h5py.
+    CondaPkg.add("hdf5"; version="<2", channel="conda-forge")
+    CondaPkg.add("h5py"; version=">=3.0,<3.13", channel="conda-forge")
     CondaPkg.add_pip("veros", version="@ https://github.com/team-ocean/veros/archive/refs/heads/main.zip")
     cli = CondaPkg.which("veros")
 

diff --git a/src/Atmospheres/Atmospheres.jl b/src/Atmospheres/Atmospheres.jl
@@ -1,6 +1,6 @@
 module Atmospheres
 
-export atmosphere_simulation, PrescribedAtmosphere
+export atmosphere_simulation, PrescribedAtmosphere, PrescribedPrecipitationFlux
 
 using Oceananigans
 using Oceananigans.Fields: Center

diff --git a/src/Atmospheres/interpolate_atmospheric_state.jl b/src/Atmospheres/interpolate_atmospheric_state.jl
@@ -27,7 +27,8 @@ function interpolate_state!(exchanger, grid, atmosphere::PrescribedAtmosphere, c
     atmosphere_tracers = (T = atmosphere.tracers.T.data,
                           q = atmosphere.tracers.q.data)
 
-    freshwater_flux = map(ϕ -> ϕ.data, atmosphere.freshwater_flux)
+    rainfall_flux = surface_rainfall_flux(atmosphere)
+    snowfall_flux = surface_snowfall_flux(atmosphere)
     atmosphere_pressure = atmosphere.pressure.data
 
     # Extract info for time-interpolation
@@ -41,12 +42,13 @@ function interpolate_state!(exchanger, grid, atmosphere::PrescribedAtmosphere, c
 
     # Simplify NamedTuple to reduce parameter space consumption.
     # See https://github.com/CliMA/NumericalEarth.jl/issues/116.
-    atmosphere_data = (u  = atmosphere_fields.u.data,
-                       v  = atmosphere_fields.v.data,
-                       T  = atmosphere_fields.T.data,
-                       p  = atmosphere_fields.p.data,
-                       q  = atmosphere_fields.q.data,
-                       Jᶜ = atmosphere_fields.Jᶜ.data)
+    atmosphere_data = (u   = atmosphere_fields.u.data,
+                       v   = atmosphere_fields.v.data,
+                       T   = atmosphere_fields.T.data,
+                       p   = atmosphere_fields.p.data,
+                       q   = atmosphere_fields.q.data,
+                       Jʳⁿ = atmosphere_fields.Jʳⁿ.data,
+                       Jˢⁿ = atmosphere_fields.Jˢⁿ.data)
 
     kernel_parameters = interface_kernel_parameters(grid)
 
@@ -67,7 +69,8 @@ function interpolate_state!(exchanger, grid, atmosphere::PrescribedAtmosphere, c
             atmosphere_velocities,
             atmosphere_tracers,
             atmosphere_pressure,
-            freshwater_flux,
+            rainfall_flux,
+            snowfall_flux,
             atmosphere_backend,
             atmosphere_time_indexing)
 
@@ -93,7 +96,8 @@ end
                                                          atmos_velocities,
                                                          atmos_tracers,
                                                          atmos_pressure,
-                                                         prescribed_freshwater_flux,
+                                                         rainfall_flux,
+                                                         snowfall_flux,
                                                          atmos_backend,
                                                          atmos_time_indexing)
 
@@ -114,8 +118,8 @@ end
     qᵃᵗ = interp_atmos_time_series(atmos_tracers.q,    atmos_args...)
     pᵃᵗ = interp_atmos_time_series(atmos_pressure,     atmos_args...)
 
-    # Usually precipitation
-    Mh = interp_atmos_time_series(prescribed_freshwater_flux, atmos_args...)
+    Mr = interp_atmos_time_series(rainfall_flux, atmos_args...)
+    Ms = interp_atmos_time_series(snowfall_flux, atmos_args...)
 
     # Convert atmosphere velocities (usually defined on a latitude-longitude grid) to
     # the frame of reference of the native grid
@@ -128,17 +132,20 @@ end
         surface_atmos_state.T[i, j, 1] = Tᵃᵗ
         surface_atmos_state.p[i, j, 1] = pᵃᵗ
         surface_atmos_state.q[i, j, 1] = qᵃᵗ
-        surface_atmos_state.Jᶜ[i, j, 1] = Mh
+        surface_atmos_state.Jʳⁿ[i, j, 1] = Mr
+        surface_atmos_state.Jˢⁿ[i, j, 1] = Ms
     end
 end
 
 #####
 ##### Utility for interpolating tuples of fields
 #####
 
+@inline interp_atmos_time_series(::Nothing, X, time, grid, args...) = 0
+
 # Note: assumes loc = (c, c, nothing) (and the third location should not matter.)
-@inline interp_atmos_time_series(J::AbstractArray, x_itp::FractionalIndices, t_itp, args...) =
-    interpolate(x_itp, t_itp, J, args...)
+@inline interp_atmos_time_series(J::AbstractArray, X::FractionalIndices, time, args...) =
+    interpolate(X, time, J, args...)
 
 @inline interp_atmos_time_series(J::AbstractArray, X, time, grid, args...) =
     interpolate(X, time, J, (Center(), Center(), nothing), grid, args...)

diff --git a/src/Atmospheres/prescribed_atmosphere.jl b/src/Atmospheres/prescribed_atmosphere.jl
@@ -42,12 +42,45 @@ function default_atmosphere_tracers(grid, times)
     return (T=Ta, q=qa)
 end
 
+"""
+    PrescribedPrecipitationFlux(; rain=nothing, snow=nothing)
+    PrescribedPrecipitationFlux(rain, snow)
+
+Container for prescribed precipitation fluxes. Either component may be `nothing`
+to indicate that the corresponding precipitation type is not represented by the
+atmosphere (e.g. rain-only datasets). Used as the `freshwater_flux` of a
+`PrescribedAtmosphere`; downstream callers query the snow component via
+[`surface_snowfall_flux`](@ref) so that prognostic atmospheres with or without
+snow can dispatch on this type as well.
+"""
+struct PrescribedPrecipitationFlux{R, S}
+    rain :: R
+    snow :: S
+end
+
+PrescribedPrecipitationFlux(; rain=nothing, snow=nothing) =
+    PrescribedPrecipitationFlux(rain, snow)
+
+Adapt.adapt_structure(to, ff::PrescribedPrecipitationFlux) =
+    PrescribedPrecipitationFlux(adapt(to, ff.rain), adapt(to, ff.snow))
+
 function default_freshwater_flux(grid, times)
     rain = FieldTimeSeries{Center, Center, Nothing}(grid, times)
     snow = FieldTimeSeries{Center, Center, Nothing}(grid, times)
-    return (; rain, snow)
+    return PrescribedPrecipitationFlux(rain, snow)
 end
 
+@inline field_data(::Nothing) = nothing
+@inline field_data(field) = field.data
+
+@inline surface_snowfall_flux(::Nothing) = nothing
+@inline surface_snowfall_flux(atmos::PrescribedAtmosphere) = surface_snowfall_flux(atmos.freshwater_flux)
+@inline surface_snowfall_flux(ff::PrescribedPrecipitationFlux) = field_data(ff.snow)
+
+@inline surface_rainfall_flux(::Nothing) = nothing
+@inline surface_rainfall_flux(atmos::PrescribedAtmosphere) = surface_rainfall_flux(atmos.freshwater_flux)
+@inline surface_rainfall_flux(ff::PrescribedPrecipitationFlux) = field_data(ff.rain)
+
 """ The standard unit of atmospheric pressure; 1 standard atmosphere (atm) = 101,325 Pascals (Pa)
 in SI units. This is approximately equal to the mean sea-level atmospheric pressure on Earth. """
 function default_atmosphere_pressure(grid, times)

diff --git a/src/Atmospheres/prescribed_atmosphere_regridder.jl b/src/Atmospheres/prescribed_atmosphere_regridder.jl
@@ -2,12 +2,13 @@ function ComponentExchanger(atmosphere::PrescribedAtmosphere, grid)
 
     regridder = atmosphere_regridder(atmosphere, grid)
 
-    state = (; u  = Field{Center, Center, Nothing}(grid),
-               v  = Field{Center, Center, Nothing}(grid),
-               T  = Field{Center, Center, Nothing}(grid),
-               p  = Field{Center, Center, Nothing}(grid),
-               q  = Field{Center, Center, Nothing}(grid),
-               Jᶜ = Field{Center, Center, Nothing}(grid))
+    state = (; u   = Field{Center, Center, Nothing}(grid),
+               v   = Field{Center, Center, Nothing}(grid),
+               T   = Field{Center, Center, Nothing}(grid),
+               p   = Field{Center, Center, Nothing}(grid),
+               q   = Field{Center, Center, Nothing}(grid),
+               Jʳⁿ = Field{Center, Center, Nothing}(grid),
+               Jˢⁿ = Field{Center, Center, Nothing}(grid))
 
     return ComponentExchanger(state, regridder)
 end

diff --git a/src/DataWrangling/ECCO/ECCO_atmosphere.jl b/src/DataWrangling/ECCO/ECCO_atmosphere.jl
@@ -1,6 +1,6 @@
 using NumericalEarth.DataWrangling: DatasetBackend
 using Oceananigans.OutputReaders
-using NumericalEarth.Atmospheres: PrescribedAtmosphere
+using NumericalEarth.Atmospheres: PrescribedAtmosphere, PrescribedPrecipitationFlux
 
 """
     ECCOPrescribedAtmosphere([architecture = CPU(), FT = Float32];
@@ -51,7 +51,7 @@ function ECCOPrescribedAtmosphere(architecture = CPU(), FT = Float32;
     pa = FieldTimeSeries(pa_meta, architecture; kw...)
     Fr = FieldTimeSeries(Fr_meta, architecture; kw...)
 
-    freshwater_flux = (; rain = Fr)
+    freshwater_flux = PrescribedPrecipitationFlux(rain = Fr)
 
     times = ua.times
     grid  = ua.grid

diff --git a/src/DataWrangling/JRA55/JRA55.jl b/src/DataWrangling/JRA55/JRA55.jl
@@ -19,7 +19,7 @@ using Oceananigans.OutputReaders: Cyclical, TotallyInMemory, AbstractInMemoryBac
 
 using NumericalEarth
 
-using NumericalEarth.Atmospheres: PrescribedAtmosphere
+using NumericalEarth.Atmospheres: PrescribedAtmosphere, PrescribedPrecipitationFlux
 using NumericalEarth.Radiations: PrescribedRadiation, SurfaceRadiationProperties, default_stefan_boltzmann_constant
 
 using GPUArraysCore: @allowscalar

diff --git a/src/DataWrangling/JRA55/JRA55_prescribed_atmosphere.jl b/src/DataWrangling/JRA55/JRA55_prescribed_atmosphere.jl
@@ -41,8 +41,7 @@ function JRA55PrescribedAtmosphere(architecture = CPU(), FT = Float32;
     Fra = JRA55FieldTimeSeries(:rain_freshwater_flux, architecture, FT; kw...)
     Fsn = JRA55FieldTimeSeries(:snow_freshwater_flux, architecture, FT; kw...)
 
-    freshwater_flux = (rain = Fra,
-                       snow = Fsn)
+    freshwater_flux = PrescribedPrecipitationFlux(rain = Fra, snow = Fsn)
 
     times = ua.times
     grid  = ua.grid

diff --git a/src/DataWrangling/OSPapa/OSPapa.jl b/src/DataWrangling/OSPapa/OSPapa.jl
@@ -15,7 +15,7 @@ using Downloads
 using Thermodynamics: q_vap_from_RH, Liquid
 
 using NumericalEarth.DataWrangling: download_progress
-using NumericalEarth.Atmospheres: PrescribedAtmosphere, AtmosphereThermodynamicsParameters
+using NumericalEarth.Atmospheres: PrescribedAtmosphere, PrescribedPrecipitationFlux, AtmosphereThermodynamicsParameters
 using NumericalEarth.Oceans: reference_density, heat_capacity
 
 using NumericalEarth.DataWrangling:

diff --git a/src/DataWrangling/OSPapa/OSPapa_prescribed_atmosphere.jl b/src/DataWrangling/OSPapa/OSPapa_prescribed_atmosphere.jl
@@ -79,7 +79,7 @@ function OSPapaPrescribedAtmosphere(architecture = CPU(), FT = Float32;
                                 velocities = (u=ua, v=va),
                                 tracers = (T=Ta, q=qa),
                                 pressure = Pa,
-                                freshwater_flux = (; rain),
+                                freshwater_flux = PrescribedPrecipitationFlux(; rain),
                                 thermodynamics_parameters = thermo_params,
                                 surface_layer_height = convert(FT, surface_layer_height))
 end