wn values is:
<code>"absolute salinity"</code>, <code>"along-spine distance km"</code>, <code>"along-track distance km"</code>,
<code>"C"</code>, <code>"conductivity mS/cm"</code>, <code>"conductivity S/m"</code>, <code>"conservative temperature"</code>,
<code>"CT"</code>, <code>"depth"</code>, <code>"direction"</code>, <code>"distance"</code>, <code>"distance km"</code>, <code>"eastward"</code>,
<code>"elevation"</code>, <code>"fluorescence"</code>, <code>"frequency cph"</code>, <code>"heading"</code>, <co