THE MAIN GOAL OF THIS STUDY IS TO UNIQUELY IDENTIFY THE NIGHTTIME PHYSICAL MECHANISMS OF EXCITATION AND QUENCHING OF CO2 MOLECULAR VIBRATIONS IN THE MESOSPHERE AND LOWER THERMOSPHERE MLT. THE PRODUCTION OF VIBRATIONALY EXCITED OH MOLECULES AND SUBSEQUENT VIBRATIONAL ENERGY TRANSFER OH N2 PROVIDES SIGNIFICANT NON THERMAL EXCITATION OF THE CO2 VIBRATIONS RESPONSIBLE FOR THE 4.3 M EMISSIONS. WE WILL UTILIZE AS DIAGNOSTICS THE NIGHTTIME LIMB OBSERVATIONS OF THE CO2 4.3 AND 15 M EMISSIONS AND OH 1.6 AND 2 M EMISSIONS OF MLT COLLECTED BY THE SABER INSTRUMENT ON BOARD THE TIMED SATELLITE. A PREVIOUS STUDY DEMONSTRATED SIGNIFICANT COUPLING OF THE CO2 4.3 AND 15 M EMISSIONS IN MLT AND APPLIED SELF CONSISTENT ANALYSIS OF SIMULTANEOUS SABER DAY TIME LIMB OBSERVATIONS OF BOTH EMISSIONS TO RETRIEVE CO2 VMR AND TEMPERATURE IN MLT FOR MORE THAN 13 YEARS OBSERVATIONS. SIMILAR SIMULTANEOUS NIGHT TIME OBSERVATIONS REMAINED HOWEVER UNPROCESSED: DUE TO THE LACK OF UNDERSTANDING OF THE NIGHT TIME 4.3 M EMISSIONS GENERATION MECHANISMS NIGHT TIME TEMPERATURES ARE STILL OPERATIONALLY RETRIEVED FROM THE SABER 15 M CHANNEL RADIANCES USING CO2 DENSITIES OBTAINED FROM THE WACCM MODEL. THE STUDY IS COMPELLING DESPITE CO2 BEING A CHEMICALLY STABLE MOLECULE ABOVE 80 KM WHERE DIURNAL TIDE HAS LARGE AMPLITUDE CO2 HAS SIGNIFICANT GRADIENTS. AS A RESULT UPWELLING DOWN WELLING PATTERNS ASSOCIATED WITH THE DIURNAL TIDE WILL PRODUCE A TIDAL SIGNATURE IN CO2 LEADING TO SIGNIFICANT DAY NIGHT CO2 DIFFERENCES AND CORRESPONDING VARIATIONS OF BOTH 4.3 AND 15 M EMISSIONS.