- Divide Area Into Tiles
- Fetch S3A OLCI & SLSTR products using SentinelHub (SH)
- Start Multiprocessing
- Simple Cloud Detection Algorithm (SCDA) & Masking Non-Ice/Snow areas
- Get Forecasted Aerosol data from Copernicus Atmospgeric Monotoring Service (cams)
- Compute outputs with pySICE
- Merge all tiles into daily mosaics
- Load all daily mosiacis to one multidimensional NetCDF file
- Upload to Dataverse and Thredds Server
The steps above are encapsulated in ./src/pysicehub.py.
In more detail:
- Every area is divided into 50km x 50km tiles with a 10 km buffer
- Download OLCI and SLSTR products for each tile concurrently through SH
- Donwloads the S3A scene with the lowest Sun Zenith Angle
- Use a specified number of cores (default is 12) to process each tile in parrallel ’
- Using SLSTR, clouds in every tile are detected and masked
- Using a predifened mask, all areas in the tile that are not snow or ice are masked
- Download raw forecasted aerosol optical depth at 550 nm and 670 nm for each tile
- interpolate and regrid to SICE 500m grid
- compute ångstrøm paramter
- Run ./src/pysice.py on all tiles
- Merge all tiles into moasic
File Name | Description | Units |
---|---|---|
grain_diameter | mm | |
snow_specific_surface_area | m2kg-1 | |
sza | sun zenith angle | |
vza | viewing zenith angle | |
saa | sun azimuth angle | |
vaa | viewing azimuth angle | |
AOD_550 | Aerosol Optical Depth (550nm) | m |
ANG | ångstrøm parameter | |
albedo_bb_planar_nir | near infrared broadband planar albedo | 700-2400 nm |
albedo_bb_planar_sw | shortwave broadband planar albedo | 300-2400 nm |
albedo_bb_planar_vis | visible broadband planar albedo | 300-700 nm |
albedo_bb_spherical_nir | near infrared broadband spherical albedo | 700-2400 nm |
albedo_bb_spherical_sw | shortwave broadband spherical albedo | 300-2400 nm |
albedo_bb_spherical_vis | visible broadband spherical albedo | 300-700 nm |
r_TOA_01..21_reflectance | top of the atmosphere reflectance (OLCI bands 1 through 21) | |
rBRR_01..21 | bottom of the atmosphere surface reflectance (OLCI bands 1 through 21) | |
albedo_spectral_planar_01..21 | spectral planar albedo (OLCI bands 1 through 21) | |
isnow | See next table. |
Diagnostic Code | Description |
---|---|
0 | clean snow |
1 | polluted snow |
6 | polluted snow for which r0 was calculated and not derived from observations |
7 | polluted snow of calculated spherical albedo in bands 1 and 2 >0.98 reprocessed as clean snow |
100 | sza>75, no retrival |
102 | TOA reflectance at band 21 < 0.1, no retrieval |
104 | grain_diameter < 0.1, no retrieval, potential cloud flag |
-n | impossible to solve polluted snow albedo equation at band n |
Run the following using ./environement.yml in order to set up an identical Anaconda Python environment.
conda env create -f environement.yml
And then run conda activate SICE
to activate the SICE environment.
ResolvePackageNotFound
error can be raised. In that case, run conda env export --no-builds > environment.yml
instead.