When the mean daily surface temperature is equal to the mean daily top of sea ice temperature,
net melting is occurring.
NOAA daily composites March 23 2017. Skin temperature (left) surface air temperature (right). Barents sea area, vicinity Franz Josef lands Russia, there is a band where Ts=Ttsi , or Ttsi is a bit warmer than surface temperature, I usually would consider this as within margin of error from Satellite acquisition, I consider the mean Ttsi= Ts there.
Skin temperature areas marked in black where the likely melting is occurring.
JAXA map, 2 days later, March 25 2017. Shows indeed melting where Ts=Ttsi
WD March 26, 2017