Eastern North Atlantic — official LASSO-ENA member

This example builds, runs, and analyzes one official LASSO-ENA ensemble member from its ARM samin input bundle (DOI 10.5439/2572661). It is a different experiment from the Covert development benchmark in eastern_north_atlantic.jl: the grid, duration, surface fluxes (bulk from SST), radiation (RRTMGP longwave and shortwave), wind nudging and aerosol setting follow the member's namelist and files. The member identity is explicit; a missing bundle stops the script with staging instructions and nothing is substituted.

Stage the bundle with julia data_wrangling/stage_lasso_bundle.jl ARCHIVE.tar, then run julia --project cases/ena_lasso.jl on an NVIDIA GPU (H100 or A100). Set ENA_LASSO_MEMBER, ENA_LASSO_BUNDLE and ENA_LASSO_EPOCH to override the member, the bundle directory and the UTC start.

using BreezeLab
using Oceananigans, Oceananigans.Units
using CairoMakie
using Dates

Identify the member and its staged bundle

20170718era5d25x100_sbmwrm-aer2-flxsst is the spectral-bin, warm-cloud, medium-aerosol, SST-flux member of 18 July 2017 forced with ERA5 (5° sampling, wind nudging only). The plan's original candidate …era5s1n0d25x100_sbmwrm-… does not exist at ARM (see docs/cases/ena_lasso.md).

member = get(ENV, "ENA_LASSO_MEMBER", "20170718era5d25x100_sbmwrm-aer2-flxsst")
bundle_dir = lasso_bundle_directory(member)
lasso_bundle_available(bundle_dir) || error(lasso_bundle_missing_message(member, bundle_dir))

Inspect the bundle before building anything

The namelist day0 and the member date fix the UTC start; SAM's day0 alone does not carry the year, so the epoch is formed explicitly here and then verified by the adapter. The documented d25x100 domain (256 × 256 × 260) is requested explicitly and checked against the bundle's grd.

inspection = inspect_lasso_bundle(bundle_dir; member, dimensions=lasso_documented_dimensions(member))
epoch = haskey(ENV, "ENA_LASSO_EPOCH") ? DateTime(ENV["ENA_LASSO_EPOCH"]) :
        epoch_from_day_of_year(inspection.time.day0; year=year(parse_lasso_member(member).date))
foreach(w -> println("note: ", w), inspection.warnings)
isempty(inspection.problems) || error("bundle cannot be reproduced:\n  - " * join(inspection.problems, "\n  - "))
println("member $member starts $epoch UTC for $(inspection.time.stop_time / 3600) h at Δt = $(inspection.time.dt) s")

Build the simulation

Everything below the member line is the protocol default read from the bundle; only the architecture, precision and output cadence are chosen here (and recorded).

arch = GPU()
FT = Float32
output_dir = joinpath(pkgdir(BreezeLab), "output", "ena_lasso", member)
case = ena_lasso(bundle_dir; member, epoch, arch, FT, output_dir, output_prefix = "ena_lasso",
                 timeseries_interval = 60seconds, profile_interval = 10minutes, slice_interval = 30minutes)
simulation = case.simulation;
nothing #hide

Run

Provenance holds the input checksums, the archive checksum and download date from bundle.toml, the member identity, the SAM reference revision and every recorded protocol difference.

mkpath(output_dir)
write_provenance(joinpath(output_dir, "provenance.toml"), case)
run!(simulation)

Analyze cloud water, rain and cloud boundaries

Model diagnostics only; the comparison against the SAM member and ARM observations over the common window is analysis/compare_ena_observations.jl.

series = breezelab_timeseries(output_dir)
bounds = breezelab_cloud_boundaries(output_dir)
hours = series.seconds ./ 3600

fig = Figure(size = (900, 900))
ax_lwp = Axis(fig[1, 1], xlabel = "Hours since $(epoch) UTC", ylabel = "Cloud liquid water path (g m⁻²)")
ax_rain = Axis(fig[2, 1], xlabel = "Hours since $(epoch) UTC", ylabel = "Surface rain rate (mm hr⁻¹)")
ax_cloud = Axis(fig[3, 1], xlabel = "Hours since $(epoch) UTC", ylabel = "Cloud base / top (m)")
lines!(ax_lwp, hours, series.lwp)
lines!(ax_rain, hours, series.rain_rate)
lines!(ax_cloud, bounds.seconds ./ 3600, bounds.base, label = "base")
lines!(ax_cloud, bounds.seconds ./ 3600, bounds.top, label = "top")
axislegend(ax_cloud, position = :rb)
Label(fig[0, 1], "LASSO-ENA member $member (Breeze; not a SAM result)", fontsize = 14)
save(joinpath(output_dir, "cloud_water_rain_boundaries.png"), fig)

This page was generated using Literate.jl.