Snow detection for flat land (snow mask) by VIS/NIR of SEVIRI

Snow Cover (SC) is the presence of snow over land. SC plays an important role in the physics of land surface as it is involved in the processes of energy and water exchange with the atmosphere. SC is useful for the scientific community, namely for those dealing with meteorological and climate models. Accurate detection of snow in a pixel is also important for a wide range of areas related to land surface processes, including meteorology, hydrology, climatology and environmental studies.

• Coverage: The SC product is computed within the area covered by the MSG disk, over 4 specific geographical regions (Europe, Africa - N_Africa and S_Africa- and South America),
• Cycle: 15 min
• Resolution: SEVIRI pixel resolution and grid
• Timeliness: 3 hours
• Dissemination: FTP - EUMETCast
• Formats: HDF5

The retrieval of SC is based on detection of cloudy, snow free and snow covered pixels in the cloud mask generated by the Nowcasting and Very Short Range Forecasting Satellite Application Facility (NWC SAF) software. The SC product is calculated daily.The Snow Cover product corresponding to the identification of snow covered pixels using Visible and Infra-Red observations is maintained by the SAF on Support to Operational Hydrology and Water Management (H-SAF).

The SC algorithm uses the cloud mask to determine the extent of snow. Cloud mask is calculated every 15 minutes. The SC product is generated from the cloud mask to classify each pixel as cloud free, cloudy or snow covered. These single SC fields are used to determine the daily SC field.