Overview =========================== This data is daily snow cover fraction, snow cover days, and snow albedo from MODIS data used in the analysis described in the following publication and shown in Figure 4, S4, and S5. Hatchett, B.J., Koshkin, A., Guirguis, K., Rittger, K., Nolin, A., Heggli, A, Rhoades, A.M., East, A.E., Siirila-Woodburn, E.R., Brandt, W.T., Gershunov, A., Haleakala, K., 2022. Midwinter Dry Spells Amplify Post-Fire Snowpack Decline. Geophysical Research Letters. 2022. doi: 10.1002/essoar.10512494.1 Dataset Metadata =========================== * Funding sources: KR was funded by NASA grants 80NSSC18K0427 and 80NSSC22K0929. BJH was supported by the National Integrated Drought Information System under agreement 1332KP21DNEEN0006. Dates and Locations * Dates of data collection: Satellite data from the NASA Aqua Terra Mission collected daily between January–May 2001 and 2022. * Geographic locations of data collection: Data acquired from MODIS over the Caldor Fire perimeter in the central Sierra Nevada, California. Methodological Information ========================== * Methods of data collection/generation: MODSCAG (Painter et al, 2009) and MODDRFS (Painter et al, 2012) outputs are gap filled for snow cover (Rittger et al, 2020) and albedo is estimated using the grain size from MODSCAG and LAP impact on albedo from MODDRFS (Bair et al, 2019). Rittger, K., Raleigh, M.S., Dozier, J., Hill, A.F., Lutz, J.A., & Painter, T.H. (2020). Canopy adjustment and improved cloud detection for remotely sensed snow cover mapping. Water Resources Research, 55, doi: 10.1029/2019wr024. Bair, E.H., Rittger, K., Skiles, S.M., & Dozier, J. (2019). An Examination of Snow Albedo Estimates From MODIS and Their Impact on Snow Water Equivalent Reconstruction. Water Resources Research, 55, 7826-7842, doi: 10.1029/2019wr024810. Painter, T.H., Rittger, K., McKenzie, C., Slaughter, P., Davis, R.E., & Dozier, J. (2009). Retrieval of subpixel snow-covered area, grain size, and albedo from MODIS. Remote Sensing of Environment, 113, 868-879, doi: 10.1016/j.rse.2009.01.001. Painter, T.H., Bryant, A.C., & Skiles, S.M. (2012). Radiative forcing by light absorbing impurities in snow from MODIS surface reflectance data. Geophysical Research Letters, 39, L17502, doi: 10.1029/2012gl052457. * Unpacking instructions: Data can be unpacked using MATLAB or OCTAVE (open-source implementation of MATLAB) “load.m” function. * Recommended software/tools: parentage- MATLAB or OCTAVE File/Folder Details =================== Details for STC-MODSCAG_MODDRFS_Terra_2001_2022_Jan-Apr_CaldorFirePerimeter.mat * Format(s): .MAT * Missing data codes: missing data are provided as NaN (“not a number”). * Variables: snow_cover_days - 81 x 226 x 22 x 4 array providing the total snow cover days. Array dimensions are X, Y, Years: 2001 to 2022, Months: Jan/Feb/Apr/May. Units are days with snow cover. snow_fraction_mean - 81 x 226 x 22 x 4 array providing the total mean snow cover fraction over the month for each year. Array dimensions are X, Y, Years: 2001 to 2022, Months: Jan/Feb/Apr/May. Units are fraction of pixel. snow_cover_days_22year_average - 81 x 226 x 4 array providing the total snow cover days for each month averaged over all years from 2001 to 2022. Array dimensions are X, Y, Months: Jan/Feb/Apr/May. Derived from snow_cover_days. snow_cover_fraction_22year_average - 81 x 226 x 4 array providing the total mean snow cover fraction over the month for each year Array dimensions are X, Y, Months: Jan/Feb/Apr/May. Derived from _snow_cover_fraction_mean mstruct - MATLAB projection structure for MODIS sinusoidal projection proj - projection coordinate references system R_in - affine spatial-referencing matrix RefMatrix - affine spatial-referencing matrix Details for BroadBandSnowAlbedo.csv, SnowCoverDays.csv, SnowCoveredArea.csv * Format(s): .CSV * Variables: summarized snow albedo snow cover days and snow covered area in separate files with column headings for years 2001 to 2022. Each row represents day of year