Data and predictors for "Global Link Between Atmospheric Heat Emission and Precipitation Isotope δ18O"

USNIP Precipitation δ18O and ERA5-Derived Predictors (1989–2014) ================================================================== DATASET OVERVIEW ----------------- This dataset accompanies the manuscript: Ajay, A., Dar, S.S., Vachon, R., Bailey, A., & Welker, J.M. (2026). Global Link Between Atmospheric Heat Emission and Precipitation Isotope δ18O. It contains monthly precipitation δ18O observations from 73 stations of the United States Network for Isotopes in Precipitation (USNIP), covering the contiguous United States (1989-2014), matched to 59 candidate predictor variables derived from ERA5 reanalysis (Hersbach et al., 2020) and ancillary climate indices. Full predictor definitions, units, and physical descriptions are provided in Table S1 of the manuscript's Supporting Information. FILE DESCRIPTION ----------------- All_data_USNIP.csv -- 12,673 rows (monthly station-month observations) x 64 columns. ACCESS RESTRICTION ------------------- These data have historically been distributed by the USNIP program upon direct request rather than through a public repository. Access is provided here via Zenodo's request mechanism, consistent with that existing data-sharing practice. Requests are reviewed by the corresponding author. COLUMN DEFINITIONS ------------------- Site : USNIP station identifier Date : Observation month (YYYY-MM-DD, day set to 1st of month) Latitude : Station latitude (degrees N) Longitude : Station longitude (degrees E) Elevationm : Station elevation (m above sea level) d1816_PWA : Precipitation-weighted-average δ18O (per mil) -- TARGET VARIABLE TP : Total precipitation (m, ERA5 accumulated) EVAP : Evaporation (m, ERA5 accumulated) -- The following 59 columns are the candidate predictors used in the Random Forest / SHAP analysis. Full physical descriptions, units, and ERA5 vs. derived source are listed in Table S1 of the paper's Supporting Information; column names here match Table S1's "Predictor variable" entries directly. -- mean_ss_down_lw_flux_clear : DLR-cs, clear-sky downward longwave radiation mean_ss_down_lw_flux : DLR all-sky, all-sky downward longwave radiation mean_ss_down_sw_flux_clear : SWR clear-sky mean_ss_down_sw_flux : SWR all-sky surf_net_solar_rad : Net solar radiation OLR : Outgoing longwave radiation potential_evap : Potential evaporation tc_water_vapour : TCWV, total column water vapour IVT : Integrated vapour transport magnitude v_int_eastward_water_vapour_flux : IVT eastward component v_int_northward_water_vapour_flux : IVT northward component ULI_mr : (see Table S1 / manuscript Methods for definition) v_int_energy : Vertically integrated atmospheric energy ResTime : Moisture residence time (TCWV / precip rate) temp_2m : T2m, 2 m air temperature skin_temperature : Surface (skin) temperature dewpoint_temp_2m : 2 m dewpoint temperature surface_pressure : Surface pressure u10, v10 : 10 m wind components (zonal, meridional) Monthly_Precip_mm : Total monthly precipitation VPD_surf : Surface vapour pressure deficit precip_type : Precipitation phase (categorical) evaporation : Actual surface evaporation SVP_surface : Surface saturation vapour pressure e_actual_surface : Surface actual vapour pressure temp_500, temp_850 : Air temperature at 500/850 hPa spec_humidity_500, spec_humidity_850 : Specific humidity at 500/850 hPa rel_humidity_500, rel_humidity_850 : Relative humidity at 500/850 hPa geopotential_500, geopotential_850 : Geopotential at 500/850 hPa vert_velocity_500, vert_velocity_850 : Vertical velocity (omega) at 500/850 hPa Q_monthly : Net column heating P_E : Precipitation minus evaporation (TP - EVAP) SVP_850, SVP_500 : Saturation vapour pressure at 850/500 hPa bl_height_v2 : Planetary boundary-layer height surf_sensible_heat_flux : Surface sensible heat flux surf_latent_heat_flux : Surface latent heat flux Thick : 850-500 hPa geopotential thickness tcc, hcc, lcc : Total/high/low cloud cover fraction conv_precip : Convective precipitation LogDist : Log-transformed distance to nearest coast SOI, ONI, NAO, PDO, AO, PNA : Climate indices (Southern Oscillation, Oceanic Nino, North Atlantic Oscillation, Pacific Decadal Oscillation, Arctic Oscillation, Pacific-North American) G : sqrt(|DLR-cs x OLR|), derived radiative coupling term (geometric mean of DLR-cs and OLR) NOTES ----- - Missing values are encoded as empty cells in the CSV. - See the manuscript's Methods (Section 2) and Table S1 for full predictor descriptions, units, and ERA5 vs. derived provenance. CITATION -------- If you use this dataset, please cite the associated manuscript (see above) and acknowledge the USNIP program as the source of the precipitation isotope observations. CONTACT ------- Jeffrey Welker, University of Alaska Anchorage ([e-mail])