Comparative Measurements of CN

(Rogers, DeMott and Kreidenweis, updated Jan 06, 1999)
This research was sponsored by NASA and NSF. plot

Simultaneous measurements of CN for a 30 minute time period on May 11, 1998 flight are shown in this plot comparing CSU, NCAR and DRI data. The overall CN structure (blue) is due to the aircraft descending. Note pressure traces (red) with lower CN concentrations at low altitudes.

The C-130 was flying a repeating pattern that crossed over itself. The CN spikes are probably narrow exhaust plumes from the C-130 or, at the lowest altitudes (highest pressures), from the SHEBA ship. Differences between the three measurements are evident, in both concentration and timing. These are more clearly shown by zooming in on a detailed plot of 200 seconds' data near the end of this time period. In the detailed view, particle concentrations from the PCASP are also shown for reference as a GREEN line.
Back to Arctic