text: Thermodynamic diagrams usually show a net of five different lines:
  * isobars = lines of constant pressure
  * isotherms = lines of constant temperature
  * dry adiabats = lines of constant potential temperature representing the temperature of a rising parcel of dry air
  * saturated adiabats or pseudoadiabats = lines representing the temperature of a rising parcel saturated with water vapor
  * mixing ratio = lines representing the dewpoint of a rising parcel
  The lapse rate, dry adiabatic lapse rate (DALR) and moist adiabatic lapse rate (MALR), are obtained.  With the help of these lines, parameters such as cloud condensation level, level of free convection, onset of cloud formation. etc. can be derived from the soundings.