05/14/01


Fred Eisele, NCAR

DMSO/NH3/CIMS

PEM Tropics B



There are two sets of files available.

Fe_dnpXX.pmb - DMSO data

Fe_nhpXX.pmb - NH3 data



Data are in different files because of different timing in measurements.



DMSO: Due to the instrumental problem, the DMSO/NH3 channel was inoperative from
flights 4-13 and 19. The detection limit for the 15-second measurement is 
estimated at 1 pptv. The error is +/- 50% except for Flight 14 where it is 
+/- 70%. Due to complications with the calibration, the concentrations for 
Flight 14 are calculated using a calibration factor determined from subsequent
flights. The uncertainty in the measurement primarily reflects uncertainty 
associated with the emission rate of the C-13 DMSO calibration permeation tube
between its pre and post deployment values.



NH3: Due to the instrumental problem, the DMSO/NH3 channel was inoperative from
flights 4-13 and 19.  Measurements were attempted on Flights 14 through 18.  
However, calibration difficulties prevented determination of NH3 values.  Previously,
information concerning relative changes in NH3 detected signal was submitted.  However,
after further analysis, due to uncertainty in the background levels and possible
changes in the background during a particular flight, these data have been removed.
For further information, contact Dr. Fred Eisele at NCAR.