----- README_AR_data.txt ----- Dataset Title: Snowpack Contributions and Temperature Characterization of Landfalling Atmospheric Rivers in the Western Cordillera of the United States Creator: J. Michelle Hu Contributors: Anne W. Nolin Keywords: Snow water equivalent, snow telemetry, snowpack, temperature measurements, mountains, hydroclimatology, snowpack fate, western U.S. License: Attribution 4.0 (CC BY 4.0) === ABSTRACT === This study utilized long-term daily precipitation and snow-water equivalent (SWE) data derived from the Natural Resources Conservation Service’s Snow Telemetry Network (SNOTEL). All existing SNOTEL sites in the Olympic, Coast and Cascade ranges in Washington (n = 66) and Oregon (n = 52) and in the California Sierra Nevada (n = 28) with data from water year (WY) 1984 to water year 2016 were included in this analysis. The Topography Weather (TopoWx) data from Oyler et al. (2015) were used in this analysis due to systemic artifacts in the raw SNOTEL data. Average daily temperatures were computed as the mean of daily minimum and maximum temperatures. Atmospheric river (AR) data were obtained from Jonathan Rutz’s “AR catalogs” and identified by a combination of feature length and integrated water vapor flux transport thresholds (IVT250) as described in Rutz et al. (2014). The Modern-Era Retrospective Analysis for Research and Applications (MERRA) data set was used for both its spatial resolution (0.5˚) and temporal coverage (from 1980–2017). Data spanning 38–49˚N and 116.25–125˚W were extracted for this study. Keywords: Atmospheric river; Hydroclimatology; Snowpack; West Coast; Extreme snowfall; === OVERVIEW === The SNOTEL_Stations_AR.csv file includes metadata (latitude, longitude, site name and site number, and state) for all SNOTEL stations used in the aforementioned regions of this analysis. The folder AR_stormData includes 184 csv files. Each csv file contains data for a single SNOTEL station. All precipitation and snow data are sourced from the NRCS SNOTEL network, while all temperature data are sourced from Topography Weather. Atmospheric river data sourced from AR Catalogs. === DATA FORMAT === [Column number] Variable (units): description [1] SNOTEL Site Number/Station ID (adimensional) [2] Month (MM) [3] Day (DD) [4] Year (YYYY) [5] tMin (deg C): daily minimum TopoWx temperature [6] tMax (deg C): daily maximum TopoWx temperature [7] tAvg (deg C): daily average TopoWx temperature [8] SWE (mm): snow water equivalent [9] delSWE (mm/day): change in daily snow water equivalent [10] P (mm): precipitation accumulation [11] delP (mm/day): change in daily precipitation accumulation [12] snowDepth (cm): snow depth [13] del_snowDepth (cm/day): change in daily snow depth [14] Storm code (adimensional): -1 = losing day (P > 0, delSWE < -5.08) 0 = neutral day (P > 0, -5.08 ≤ delSWE ≤ 5.08) 1 = gaining day (P > 0, delSWE > 5.08) 200 = no delSWE value 300 = no delP value 400 = no delP, no delSWE 601 = delP = 0, delSWE >= 5.08 701 = delP = 0, delSWE <= -5.08 9999 = error code [15] AR Month (MM) [16] AR Day (DD) [17] AR Year (YYYY) [18] AR Hours (HH) [19] IVT (kg/m/s): integrated water vapor transport [20] AR? (adimensional): 1 = AR [21] new AR? (adimensional): 1 = yes 0 = no [22] AR duration (hours): single AR event defined by continuous IVT exceedence of 250 kg/m/s [23] AR Cat* (adimensional): AR category as defined by F. Martin Ralph and contributors (http://cw3e.ucsd.edu/wp-content/uploads/2017/07/FIRO_Science_Workshop/PDFs/MRalph_ARs.pdf) [24] Storm-total IVT (*10^7 kg/m): cumulative IVT of single AR storm event === CONTACT === J. Michelle Hu (hujy@oregonstate.edu, now at: jmhu@uw.edu) === SUGGESTED CITATION === Hu, J. M. (2018). Snowpack Contributions and Temperature Characterization of Landfalling Atmospheric Rivers in the Western Cordillera of the United States (Version 1) [Data set]. Oregon State University. https://doi.org/10.7267/VQ27ZT874 === DIGITAL OBJECT IDENTIFIER (DOI) === 10.7267/vq27zt874 === EXTERNAL CITATIONS === Oyler, J. W., Ballantyne, A., Jencso, K., Sweet, M., & Running, S. W. (2015). Creating a topoclimatic daily air temperature dataset for the conterminous United States using homogenized station data and remotely sensed land skin temperature: Topoclimatic Daily Air Temperature. International Journal of Climatology, 35(9), 2258–2279. https://doi.org/10.1002/joc.4127 Rutz, J. J., Steenburgh, W. J., & Ralph, F. M. (2014). Climatological characteristics of atmospheric rivers and their inland penetration over the western United States. Monthly Weather Review, 142(2), 905–921. https://doi.org/10.1175/MWR-D-13-00168.1 === EXTERNAL SOURCES === NRCS Snow Telemetry Network (https://www.wcc.nrcs.usda.gov/snow/) Topography Weather from Oyler et al., 2015 (http://www.scrimhub.org/resources/topowx/) AR Catalogs from Rutz et al., 2014 (http://www.inscc.utah.edu/~rutz/ar_catalogs/merra_0.5/timeseries/ and http://journals.ametsoc.org/doi/abs/10.1175/MWR-D-13-00168.1) === LICENSE === Attribution 4.0 (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/ === ACKNOWLEDGEMENTS === This work was supported by the National Aeronautics and Space Administration under grant #NNX16AG35G.