snowpack-elevation-warming-utac

GenesisAeon Package 110 — the seasonal snow buffer is eroding. Quantifies a buffer type that distributed-buffer-resilience-utac (P103) names but leaves unquantified: "snow (seasonal)" as one of five hydrological buffer types. Also extends glacier-buffer-utac (P99)'s "peak water" framing to the faster, annually-recurring seasonal snowpack. Deliberately has no UTAC/CREP/AFET bridge — see DISCLAIMER.md.

Deliberately not one-sided

This package includes a real, important complication of the "snow is disappearing everywhere, in every season" narrative, not just confirmation of it. is_snow_decline_spatially_universal() returns False on purpose — northern High Mountain Asia (Karakoram, Kunlun Shan, Pamir) shows a positive snow cover extent trend, and global spring (MAM) snow cover extent trends positive even as winter (DJF) declines steeply.

What's real here

• Pepin, Bradley, Diaz, Baraer, Caceres, Forsythe et al. (2015, Nature Climate Change) — a real synthesis review: warming is amplified with elevation in many mountain regions, via up to five candidate mechanisms (snow-albedo feedback, water vapor/latent heat, radiative flux, surface heat loss, aerosols) that produce contrasting regional patterns, not one uniform global rate — this package deliberately does not attribute a single global degrees-per-decade figure to this citation, because the paper itself does not report one.
• Matiu, Crespi, Bertoldi, Carmagnola, Marty, Morin et al. (2021, The Cryosphere) — a real, large European Alps station network (2,000+ stations, 800+ used for trend assessment, six countries, 1971–2019): seasonal mean snow depth declined -8.4%/decade, maximum snow depth and snow cover duration each declined -5.6%/decade, with southern Alpine regions declining measurably faster than northern ones.
• Notarnicola (2022, Scientific Reports) — the honesty check: a real satellite-based global mountain analysis (1982–2020) found overall snow cover extent down -3.6%±2.7% and duration down -15.1±11.6 days, but winter (DJF) declined steeply (-11.5%±6.9%) while spring (MAM) trended positive (+10.0%±5.9%), and northern High Mountain Asia (Karakoram, Kunlun Shan, Pamir) shows a positive trend — consistent with the independently documented "Karakoram anomaly" in glacier mass balance — while southern High Mountain Asia declines.
• Mote, Li, Lettenmaier, Xiao, Engel (2018, npj Climate and Atmospheric Science) — a real, large western US snow-course/ SNOTEL network (1,766 sites, since 1915): more than 90% of sites show a decline, about a third of those declines are individually statistically significant, and the average decline is 15–30% since the start of record.

Quickstart

pip install snowpack-elevation-warming-utac

from snowpack_elevation_warming_utac import (
    edw_candidate_mechanisms,
    is_globally_uniform_pattern,
    ALPINE_SNOW_TREND,
    is_decline_spatially_uniform,
    GLOBAL_SNOW_TREND,
    winter_vs_spring_extent_trend_pct,
    is_snow_decline_spatially_universal,
    WEST_US_SNOWPACK_TREND,
    majority_of_sites_declining,
)

print(edw_candidate_mechanisms())
print(is_globally_uniform_pattern())            # False
print(ALPINE_SNOW_TREND.seasonal_mean_depth_pct_per_decade)  # -8.4
print(GLOBAL_SNOW_TREND.extent_pct)              # -3.6
print(winter_vs_spring_extent_trend_pct())       # {"winter_djf": -11.5, "spring_mam": 10.0}
print(is_snow_decline_spatially_universal())     # False
print(WEST_US_SNOWPACK_TREND.pct_sites_declining)  # 90
print(majority_of_sites_declining())             # True

Development

pip install -e ".[dev]"
pre-commit install
ruff check src tests
mypy src
pytest

Citation

See CITATION.cff and .zenodo.json.