3.3
Ozone and aerosol measurements with airborne lidar during the 2004 Intercontinental Chemical Transport Experiment - North America (INTEX-NA) field experiment: Initial results
Edward V. Browell, NASA Langley Research Center, Hampton, VA; and J. W. Hair, C. F. Butler, S. A. Kooi, A. Notari, S. Ismail, and M. A. Fenn
The NASA Langley Airborne Differential Absorption Lidar (DIAL) system was flown on the NASA DC-8 aircraft during the Intercontinental Chemical Transport Experiment - North America (INTEX-NA) conducted from 1 July to 12 August 2004 over North America and the adjacent oceans from bases at Edwards Air Force Base, California; St. Louis, Missouri; and Portsmouth, New Hampshire. The objective of this major international field experiment was the investigation of long-range transport of pollution from Asia to North America (NA); the production and transport mechanisms of pollution over NA; and the transport and transformation of pollution from NA over the Atlantic Ocean toward Europe. The airborne DIAL system was used to measure ozone and aerosol profiles from near the surface to above the tropopause along the flight track of the DC-8 to determine the large-scale variability of air masses being sampled in situ on the DC-8 and to plan and direct the in situ sampling strategy in real time. The DIAL system was operated simultaneously in a nadir and zenith mode from the DC-8 with four laser wavelengths of 289, 300, 588/600, and 1064 nm being transmitted in both directions at 30 Hz to obtain ozone and aerosol backscatter and depolarization profiles for large-scale air mass characterization. Pollution layers from Asia were observed in the extreme eastern Pacific and possibly as far east as over east coast of NA. Depolarizing aerosol plumes from Alaskan forest fires were observed from eastern Canada to the southeastern United States. Pollution from NA was transported into the north Atlantic in the mid to upper troposphere as a result of uplifting ahead of a front in a warm conveyer belt (WCB) and in association with up-wind convection. Polluted air masses from NA with different ages were also observed over the Atlantic. Air masses containing a mix of pollution sources along with very high ozone, which is indicative of stratospherically-influenced air, were often observed in the upper troposphere. Initial results from the INTEX-NA field experiment are presented in this paper.
Session 3, Clouds, Climate, Chemistry and air quality
Monday, 10 January 2005, 4:00 PM-5:45 PM
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