Frequently Asked Questions

Routing network: Why are there 9s in the file, and how should I treat them?
The 9s in the routing network represent the cells in the landmask that are not included in the DDM30 network. Please treat them as outlets/sinks. These cells are given basin numbers from 70000 and upwards in the basin mmber file (i.e. one-cell basins).  

What does "averaged over the grid cell" mean?

 

Snow throughfall (Qst), what exactly is it, and how is it different from the ALMA snow melt? Snow througfall (Qst) represents liquid water flowing out of the snow pack, meaning water (melted snow and/or rain) percolating through the snowpack. Snow melt (Qsm, which is not a requested output variable in the 2008 rounds) is snow that melts in the snowpack, but it doesn't necessarily leave the snowpack (can stay in the snowpack as liquid water, and may refreeze later on).