TRACE-P Informal Instrument Intercomparison
Abstract
The NASA DC-8 and P-3B aircraft were flown along side of each other in close proximity on 3 different occasions during the TRACE-P mission. The duration of these adjacent flights, during which instruments on the two aircraft could be compared, ranged from about 25 to 78 minutes. High time resolution measurements such as O3, CO, CH4, and CO2 present on the two aircraft both showed good agreement between aircraft and provided a measure of second or subsecond time lags between aircraft as each entered similar air mass structures. Dozens of measurements were intercompared, and as expected in general measurements of more abundant, longer lived compounds agreed better than less abundant, shorter-lived compounds, though this was not always the case. Measurements of O3, CO, CO2, CH4 agreed extremely well. Measurements of NO, PAN and to a lesser extent HNO3 also agreed quite well. Many of the other measurements also agreed within the combined limits of errors of the two measurements particular at high concentrations but there were also some cases where discrepancies were quite significant. Over all the intercomparison was highly successful pointing out potential problems and providing a means to evaluate differences in measurement/model discrepancies on the two aircraft. While intercomparisons conducted during a mission are limited in extent, they provide the unique opportunity to intercompare the actual instrument and inlet configurations used on the mission at various time periods throughout the study. This type of intercomparison can in some cases also help identify erroneous instrument operation just prior to a mission allowing corrective action early in the study.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2002
- Bibcode:
- 2002AGUFM.A51D..03E
- Keywords:
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- 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0365 Troposphere: composition and chemistry;
- 0368 Troposphere: constituent transport and chemistry