Construction of a unified, high-resolution nitrous oxide data set for ER-2 flights during SOLVE : SAGE III-Ozone Loss Validation Experiment and Third European Stratospheric Experiment on Ozone-2000 (SOLVE/THESEO)

[1] Four nitrous oxide (N 2 O) instruments were part of the NASA ER-2 aircraft payload during the 2000 SAGE-III Ozone Loss and Validation Experiment (SOLVE). Coincident data from the three in situ instruments and a whole air sampler are compared. Agreement between these instruments was typically good; however, there are several types of important differences between the data sets. These differences prompted a collaborative effort to combine data from the three in situ instruments, using an objective method, to produce a self-consistent, high-resolution, unified N 2 O data set for each SOLVE flight. The construction method developed by the four N 2 O instrument teams is described in detail. An important step in this method is the evaluation and reduction of bias in each of the in situ data sets before they are combined. The quality of unified N 2 O data is examined through its agreement with high-accuracy and high-precision N 2 O data from whole air samples collected from the ER-2 during SOLVE flights. Typical agreement between these two data sets is 2.9 ppb (1.5%), better than the typical agreement between anv nair of N 2 O instruments.