This directory contains masking data to specify grid points and periods affected by bugs in JRA-55 snow depth analysis.

1. Directory structure
 YYYY: year, MM: month
 *.ctl@GrADS (see Subsection S2.3) control file
 *.pdef GrADS definition file for projection

Mask -+- mask1_LL125 -+- mask1_LL125_YYYYMM.dat	(1-byte integer data)
                      +- ...
                      +- mask1_LL125.monthly.ctl
      +- mask1_TL319 -+- TL319_general.pdef
                      +- mask1_TL319_YYYYMM.dat	(1-byte integer data)
                      +- ...
                      +- mask1_TL319.monthly.ctl
      +- mask2_LL125 -+- mask2_LL125_monMM.dat	(1-byte integer data)
                      +- ...
                      +- mask2_LL125.monthly.ctl
      +- mask2_TL319 -+- TL319_general.pdef
                      +- mask2_TL319_monMM.dat	(1-byte integer data)
                      +- ...
                      +- mask2_TL319.monthly.ctl

2. Data format
2.1. Masking data for areas and periods with unrealistically deep snow values (1.25-degree latitude/longitude grid data) (mask1_LL125)
* Data type: 1-byte integer
* Values: 1 for grid points with errors and 0 for others
* File organization:
The first 288 bytes of the files contain data for the 90th parallel north, starting from zero degrees longitude (the prime meridian) toward the east at intervals of 1.25 degrees. The remaining parallels follow at intervals of 1.25 degrees toward the south.
* File composition:
Monthly files for the period from January 1958 to June 2016 (702 in total)

2.2.2. Masking data for areas and periods with unrealistically deep snow values (model grid data) (mask1_TL319)
* Data type: as per mask1_LL125
* Values: as per mask1_LL125
* File organization:
The first 48 bytes of the files contain data for the northernmost parallel, starting from zero degrees longitude (the prime meridian) toward the east. The remaining parallels follow toward the south. The number of grid points in each parallel varies with latitude. For details of the latitude and the number of grid points in each parallel of the model grid, see the JRA-55 product usersf handbook (Model grid data; http://jra.kishou.go.jp/JRA-55/index_ja.html#manual).
* File composition: as per mask1_LL125

2.2.3. Masking data for grid points with errors in snow cover climatology interpolation (1.25-degree latitude/longitude grid data) (mask2_LL125)
* Data type: as per mask1_LL125
* Values: as per mask1_LL125
* File organization: as per mask1_LL125
* File composition:
Monthly files from January to December (12 in total)

2.2.4. Masking data for grid points with errors in snow cover climatology interpolation (model grid data) (mask2_TL319)
* Data type: as per mask1_LL125
* Values: as per mask1_LL125
* File organization: as per mask1_TL319
* File composition: as per mask2_LL125

3. Checking for impacts on the variables listed in Section S1
* Snow depth (and water equivalent of accumulated snow depth)
Users are advised to check both the masking data for areas and periods with unrealistically deep snow values and the masking data for grid points with errors in snow cover climatology interpolation.

* Upward solar radiation flux
Users are advised to check the masking data for grid points with errors in snow cover climatology interpolation.

* Sensible heat flux
Users are advised to check the masking data for grid points with errors in snow cover climatology interpolation.
