@BeginModule
@NewPage
@Name      = EcaFdns
@Title     = No. of frost days without surface snow 
@Section   = ECA indices
@Class     = ECA index
@Arguments = ifile1 ifile2 ofile
@Operators = eca_fdns

@BeginDescription
Let @file{ifile1} be a time series of daily minimum temperatures TN
and @file{ifile2} be a corresponding series of daily surface snow
amounts. Then counted is the number of days where TN < 0° Celsius
and the surface snow amount is less than 1 cm.
The date information for a time step in @file{ofile} is the date of
the last contributing time step in @file{ifile}.
@EndDescription
@EndModule


@BeginOperator_eca_fdns
@Title     = No. of frost days without surface snow
@EndOperator
