Each file contains HadTH adjustment estimates for a single member of an ensemble
of homogenisations. The file naming convention is:

"hadth_[day,night]_[T,RH,q]_NH_[1,..,100]"

Where the data are for day or night launches, 
Temperature(T), Relative Humidity(RH), specific humidity(q)
for ensemble members 1 through to 100

The QUARC methodology makes no judgement on any one homogenisation member 
being better than another, so we consider all as plausible realisations of 
the HadTH homogenisation process.

Data files are column oriented with columns
station id : The WMO station id
Pressure level : The standard pressure level the adjustment is assocaited with
                 1010=surface level
Breakpoint date : The date of change as YYYYMM
Magnitude: The magnitude of adjustment (K, %, g/kg)

The adjustments are applied to all dates prior to the breakpoint date.