An investigation of the cooling of N-2((CIIu)-I-3,v’,J’) in a corona supersonic discharge of pure nitrogen is presented. Ideal gas calculations illustrate the essentials of expansion cooling and radiative and collisional relaxation. The spectra of the N-2 (CIIu)-I-3-->B3IIg emission are presented. An indirect method (computer program) arrives at the rotational population distributions of the upper state. Notably, non-Boltzmann population distributions are characteristic of emitting N-2((CIIu)-I-3,v’,J) in the free jet expansion. The disparate roles played by radiative and collisional relaxation of metastables in the postnozzle gas flow are discussed.