Intercomparison of NO Column Measurements During MAP/GLOBUS 1985

Column measurements of nitric oxide were made using several techniques
during the MAP/GLOBUS campaign in France in September 1985. The data
sets are nearly co-located and simultaneous, therefore allowing a valid
intercomparison of the various measurement methods. The range of
altitudes sampled differs from instrument to instrument. This complicates
the comparison because the data sets are to some extent complementary.
The NO distributions apparently vary significantly from day to day, and
possibly over shorter timescales. Changes in dynamics may be responsible
for these variations. The results from the instruments which measure in
the infrared and the ultraviolet are self-consistent, and show good
agreement with photochemical predictions. On 19 September, when the
intercomparison was made, the profile measured by the in-situ chemi-
luminescent instrument differed significantly from the predicted profile,
and the measured columns were generally higher.