What is difference between mintra level and freezing level?

Question

it is used in meterology for the study of contrails temperature made by jetplanes

Answer 1

Freezing level is the height above mean sea level where the temperature is zero degrees C.  This level is dependent on temperature.  Exact icing to occur once you fly above this level.

If I remember correctly, the Mintra level marks the level of height above means sea level where aircraft contrails are not expected to form once an Craft flies above this level.  It is dependent on both the temperature and the pressure.  I think they use -11 degrees C as the rough estimated height level

I'm not positive on the Mintra level definition, so it may be best that you double check this from an aviation/weather web site or glossary.