Subtree-merge thermograph-backend era5-seed into backend/

This commit is contained in:
Emi Griffith 2026-07-22 22:26:27 -07:00
commit 9567c51783
3 changed files with 255 additions and 0 deletions

View file

@ -0,0 +1,9 @@
# Seed-only dependencies for seed_era5.py (the one-time ERA5 backfill). NOT installed
# in the app image or CI — kept out of requirements.txt so the runtime stays lean.
# Install on the machine that runs the seed: pip install -r requirements-seed.txt
# Versions intentionally unpinned: the icechunk/xarray/zarr stack moves fast; install
# the current compatible set on the seed box and verify with `python seed_era5.py --dry-run`.
-r requirements.txt
icechunk
xarray
zarr

174
backend/seed_era5.py Normal file
View file

@ -0,0 +1,174 @@
"""One-time ERA5 seed for the curated-city cells (keeps ERA5 fidelity without Open-Meteo).
Now that the live history primary is NASA POWER, this backfills the high-traffic
curated-city cells (backend/cities.json) with true ERA5 data pulled from a public,
KEYLESS source the Earthmover Icechunk ERA5 archive on AWS Open Data so the
pages people actually visit keep ERA5-quality history. It writes straight into the
history store (bypassing the live fetch), so a seeded cell is served from cache and
never falls to NASA on first request.
# on a machine with network + the seed deps (see requirements-seed.txt):
pip install -r requirements-seed.txt
python seed_era5.py --dry-run # fetch+transform one cell, print, no write
python seed_era5.py [--limit N] [--overwrite]
Idempotent by default: a cell that already has a cached history is skipped (pass
--overwrite to reseed). Not run in CI or the app image the icechunk/xarray/zarr
stack lives only in requirements-seed.txt.
IMPORTANT the S3/Icechunk *access* layer (_open_store / fetch_point) targets a
young, fast-moving API and the store's exact variable/coordinate names; it is NOT
exercised by the test suite. VERIFY it with `--dry-run` on the seed box before a
full run. The hourlydaily transform (hourly_to_daily) IS unit-tested and is the
part that must be numerically correct.
Source: https://registry.opendata.aws/earthmover-era5/ (group="temporal", anonymous)
"""
import os
import sys
import polars as pl
from data import cities
from data import climate
from data import grid
# Match the live archive span (climate.START_DATE / ARCHIVE_LATENCY_DAYS).
START_DATE = climate.START_DATE # "1980-01-01"
# Anonymous AWS Open Data Icechunk store; overridable in case the registry moves.
ERA5_BUCKET = os.environ.get("THERMOGRAPH_ERA5_BUCKET", "earthmover-icechunk-era5")
ERA5_PREFIX = os.environ.get("THERMOGRAPH_ERA5_PREFIX", "") # verify on the seed box
ERA5_REGION = os.environ.get("THERMOGRAPH_ERA5_REGION", "us-east-1")
ERA5_GROUP = os.environ.get("THERMOGRAPH_ERA5_GROUP", "temporal") # time-contiguous layout
# ERA5 store variable name -> our short name. ERA5 gusts (i10fg) are real here, so the
# seed keeps genuine measured gusts rather than the Meteostat/estimate fallback.
ERA5_VARS = {
"2m_temperature": "t2m", # K
"2m_dewpoint_temperature": "d2m", # K (→ RH with t2m)
"total_precipitation": "tp", # m, hourly accumulation
"10m_u_component_of_wind": "u10", # m/s
"10m_v_component_of_wind": "v10", # m/s
"instantaneous_10m_wind_gust": "i10fg", # m/s
}
_M_TO_IN = 39.37007874
_MS_TO_MPH = 2.2369362920544
def hourly_to_daily(hourly: pl.DataFrame) -> pl.DataFrame:
"""Aggregate an hourly ERA5 point frame to the daily schema climate.py stores,
in the app's units (°F, inches, mph, %RH). Input columns: time (Datetime, UTC),
t2m/d2m (K), tp (m, per-hour accumulation), u10/v10/i10fg (m/s).
Days are UTC calendar days the reanalysis is UTC, so this is a small offset
from a local-timezone daily boundary, immaterial for percentile climatology.
Relative humidity is the Magnus-formula RH from temperature and dewpoint."""
tc = pl.col("t2m") - 273.15
tdc = pl.col("d2m") - 273.15
es = (17.625 * tc / (243.04 + tc)).exp()
e = (17.625 * tdc / (243.04 + tdc)).exp()
df = hourly.with_columns(
pl.col("time").dt.date().alias("date"),
((pl.col("t2m") - 273.15) * 9.0 / 5.0 + 32.0).alias("t_f"),
((pl.col("u10") ** 2 + pl.col("v10") ** 2).sqrt() * _MS_TO_MPH).alias("wind_mph"),
(pl.col("i10fg") * _MS_TO_MPH).alias("gust_mph"),
(pl.col("tp") * _M_TO_IN).alias("precip_in"),
(100.0 * e / es).clip(0.0, 100.0).alias("rh"),
)
return (
df.group_by("date")
.agg(
pl.col("t_f").max().alias("tmax"),
pl.col("t_f").min().alias("tmin"),
pl.col("precip_in").sum().alias("precip"),
pl.col("wind_mph").max().alias("wind"),
pl.col("gust_mph").max().alias("gust"),
pl.col("rh").mean().alias("humid"),
)
.sort("date")
)
def _default_end() -> str:
import datetime
return (datetime.date.today()
- datetime.timedelta(days=climate.ARCHIVE_LATENCY_DAYS)).isoformat()
def _open_store():
"""Open the anonymous Icechunk ERA5 store (temporal group). Lazy-imports the
seed-only deps. VERIFY against the current icechunk/xarray API on the seed box
this young API and the store's exact paths are not covered by tests."""
import icechunk # noqa: PLC0415 - seed-only dep (requirements-seed.txt)
import xarray as xr # noqa: PLC0415
storage = icechunk.s3_storage(
bucket=ERA5_BUCKET, prefix=ERA5_PREFIX, region=ERA5_REGION, anonymous=True)
repo = icechunk.Repository.open(storage)
session = repo.readonly_session("main")
return xr.open_zarr(session.store, group=ERA5_GROUP, consolidated=False)
def fetch_point(ds, lat: float, lon: float, start: str, end: str) -> pl.DataFrame:
"""Pull the hourly ERA5 series for the nearest grid point over [start, end] into a
polars frame (no pandas). ERA5 longitudes are 0..360. Coordinate/variable names
may differ per store revision verify with --dry-run."""
sub = (ds[list(ERA5_VARS)]
.sel(latitude=lat, longitude=lon % 360.0, method="nearest")
.sel(time=slice(start, end))
.load())
data = {"time": sub["time"].values}
for src, dst in ERA5_VARS.items():
data[dst] = sub[src].values
return pl.DataFrame(data)
def seed_cell(ds, cell: dict, start: str, end: str) -> int:
"""Fetch → daily → finalize → write one cell's ERA5 history. Returns row count."""
daily = hourly_to_daily(fetch_point(ds, cell["center_lat"], cell["center_lon"], start, end))
# ERA5 has no apparent-temperature field; approximate fmax/fmin from the NWS heat
# index / wind chill (same as the NASA/MET paths). _finalize_approximated adds
# feels + doy and folds NaN→null; the write path strips doy.
frame = climate._finalize_approximated(daily)
climate._write_history_backed(cell["id"], frame)
return frame.height
def main(limit: "int | None" = None, overwrite: bool = False,
dry_run: bool = False, start: str = START_DATE, end: "str | None" = None) -> None:
end = end or _default_end()
ds = _open_store()
todo = cities.all_cities()
if limit:
todo = todo[:limit]
seeded = skipped = failed = 0
for i, c in enumerate(todo, 1):
cell = grid.snap(c["lat"], c["lon"])
if not overwrite:
cached = climate.load_cached_history(cell)
if cached is not None and not cached.is_empty():
skipped += 1
continue
try:
if dry_run:
daily = hourly_to_daily(
fetch_point(ds, cell["center_lat"], cell["center_lon"], start, end))
print(daily.head())
print(f"[dry-run] {c['slug']} ({cell['id']}): {daily.height} days "
f"({start}..{end}); nothing written")
return
n = seed_cell(ds, cell, start, end)
seeded += 1
print(f"[{i}/{len(todo)}] seeded {c['slug']} ({cell['id']}): {n} days")
except Exception as e: # noqa: BLE001 - keep going; a failed cell self-heals via NASA
failed += 1
print(f"[{i}/{len(todo)}] FAILED {c['slug']}: {e}")
print(f"done: seeded={seeded} skipped(cached)={skipped} failed={failed}")
if __name__ == "__main__":
argv = sys.argv[1:]
lim = int(argv[argv.index("--limit") + 1]) if "--limit" in argv else None
main(limit=lim, overwrite="--overwrite" in argv, dry_run="--dry-run" in argv)

View file

@ -0,0 +1,72 @@
"""Unit tests for the ERA5 seed's hourly→daily transform (hermetic — no network, no
icechunk/xarray). The S3 access layer (_open_store/fetch_point) is deliberately not
tested here; it must be verified with `seed_era5.py --dry-run` on the seed box."""
import datetime
import math
import polars as pl
import pytest
import seed_era5
_MS_TO_MPH = 2.2369362920544
_M_TO_IN = 39.37007874
def _rh(t_c, td_c):
es = math.exp(17.625 * t_c / (243.04 + t_c))
e = math.exp(17.625 * td_c / (243.04 + td_c))
return min(100.0, 100.0 * e / es)
def _hourly(rows):
"""rows: list of (time, t2m_K, d2m_K, tp_m, u10, v10, i10fg)."""
cols = ["time", "t2m", "d2m", "tp", "u10", "v10", "i10fg"]
return pl.DataFrame({c: [r[i] for r in rows] for i, c in enumerate(cols)})
def test_hourly_to_daily_aggregates_and_converts():
d1 = datetime.datetime(2020, 1, 1)
d2 = datetime.datetime(2020, 1, 2)
hourly = _hourly([
# day 1: 10°C sat, then 20°C / 10°C dew; winds 5 m/s then calm; gusts 10/12
(d1.replace(hour=0), 283.15, 283.15, 0.001, 3.0, 4.0, 10.0),
(d1.replace(hour=1), 293.15, 283.15, 0.002, 0.0, 0.0, 12.0),
# day 2: 0°C sat; wind 10 m/s; gust 20
(d2.replace(hour=0), 273.15, 273.15, 0.0, 6.0, 8.0, 20.0),
])
daily = seed_era5.hourly_to_daily(hourly).sort("date")
assert daily["date"].to_list() == [datetime.date(2020, 1, 1), datetime.date(2020, 1, 2)]
r0 = daily.row(0, named=True)
assert r0["tmax"] == pytest.approx(68.0) # 20°C
assert r0["tmin"] == pytest.approx(50.0) # 10°C
assert r0["precip"] == pytest.approx(0.003 * _M_TO_IN)
assert r0["wind"] == pytest.approx(5.0 * _MS_TO_MPH) # max(5, 0)
assert r0["gust"] == pytest.approx(12.0 * _MS_TO_MPH) # max(10, 12)
assert r0["humid"] == pytest.approx((_rh(10, 10) + _rh(20, 10)) / 2)
r1 = daily.row(1, named=True)
assert r1["tmin"] == pytest.approx(32.0) # 0°C
assert r1["wind"] == pytest.approx(10.0 * _MS_TO_MPH) # sqrt(6²+8²)
def test_saturated_air_reads_full_humidity():
hourly = _hourly([(datetime.datetime(2021, 6, 1), 293.15, 293.15, 0.0, 1.0, 1.0, 2.0)])
daily = seed_era5.hourly_to_daily(hourly)
assert daily.row(0, named=True)["humid"] == pytest.approx(100.0)
def test_finalize_produces_the_store_schema():
"""The daily frame, run through climate._finalize_approximated (as seed_cell does),
yields the persisted columns incl. derived feels."""
from data import climate
hourly = _hourly([
(datetime.datetime(2019, 7, 1, 0), 300.0, 290.0, 0.0, 2.0, 2.0, 5.0),
(datetime.datetime(2019, 7, 1, 1), 305.0, 291.0, 0.001, 3.0, 1.0, 7.0),
])
frame = climate._finalize_approximated(seed_era5.hourly_to_daily(hourly))
for col in ("date", "tmax", "tmin", "precip", "wind", "gust", "humid",
"fmax", "fmin", "feels"):
assert col in frame.columns
assert frame.height == 1