Clouds and Trace Gas Trends Observed During TRACE-P
Abstract
During NASA's TRACE-P (Transport and Chemical Evolution over the Pacific) mission, airborne sampling was aimed at characterizing trace gas distributions along the Asian Pacific Rim in various types of outflow. These emanations were most often associated with the passage of cold fronts. On a few occasions, the P-3B and DC-8 penetrated frontal cloud bands. Observations during these periods exhibited enhanced trace gas levels compared to the surrounding atmosphere. While physical penetration of clouds accounts for only one tenth of the data, an examination of the entire dataset was conducted to evaluate trends between cloudy and clear areas. This was diagnosed by comparing both measurements and clear-sky calculations of the photolysis frequency of NO2 (i.e., jNO2). Median statistics based on this diagnostic suggest enhanced levels of CO and other species both above and below cloudy regions as compared to clear regions. For short-lived species, there is evidence of rapid photochemical loss in outflow above clouds and extended lifetime below clouds. These observations have important implications for both understanding the evolution of outflow from the Asian Pacific Rim as well as the interpretation of remotely sensed trace gas distributions.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2002
- Bibcode:
- 2002AGUFM.A62A0142C
- Keywords:
-
- 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0360 Transmission and scattering of radiation;
- 0365 Troposphere: composition and chemistry