#for file in *png ; do echo mv $file `echo $file|sed -e 's/density_01_//' | sed -e 's/isopicne/isopycne/'`; done
for file in *png ; do      mv $file `echo $file|sed -e 's/density_01_//' | sed -e 's/isopicne/isopycne/'`; done

for var in "thetao" "so" "o2" "no3" ; do
   echo $var
#  for file in *${var}-${var}*png ; do echo mv $file `echo $file|sed -e "s/${var}-${var}/${var}-ref/"`; done
   for file in *${var}-${var}*png ; do      mv $file `echo $file|sed -e "s/${var}-${var}/${var}-ref/"`; done
done