asn_variable

Improved snow-melting model

Snow melting is an important component of the hydrological cycle, in particular in mountainous areas.  Modelling adequately this process is therefore important.

This led to the improvement of the snow-melting equations of the Snow-GSM, GSM and SOCONT models in RS MINERVE. Until now, the degree-day snowmelt coefficient, defining the quantity of melted snow per day as a function of temperature (mm/°C/day), was a constant factor. In the latest release of RS MINERVE, this coefficient can now vary over the year (see title image). The new parametrization is given by :

  • A reference degree-day snowmelt coefficient (Asn)
  • A degree-day snowmelt interval (AsnInt)
  • A phase shift of the sinusoidal function (AsnPh)

The first parameter defines the average degree-day snowmelt coefficient and the second parameter the interval of variation of the coefficient over the year. The third parameter defines the phase shift of the sinusoidal curve with respect to the first day of the year. As a first guess, it is recommend to use the day number of the year corresponding to the beginning of spring (80 for the Northern hemisphere, 264 for the Southern hemisphere).