The revised MS can be accepted for publication after a few minor corrections:
(1) A scan step of 0.01 cm-1 (line 2, page 4) was given, which determines the frequency precision of the spectrum recorded by the instrument. What is the accuracy of the step control? How stable it is? It needs to be clarified.
(2) As the authors described, the values of the concentrations given in the MS is actually a relative value of the relative abundance of N2O/CH4 in air. No calibration of the results has been performed. Taking into account the drift of the scan step, I doubt that it might be impossible to calibrate the value to a 0.1% precision.
(3) It is meaningless to assign 3 digits for all the values of the "sensitivity".

Regarding Figure 8, what were the time resolution used for CH4 and N2O mornitoring? what was the reason to use such long integration time? What is the comment of the authors on the "oscillation-like" variation in the time-series measurement of N2O concentration?