HR: 1340h
AN: A33A-0816    [Abstracts]
TI: Observations of Ozone and Aerosols Over Mexico and Gulf of Mexico During INTEX- B/MILAGRO Field Experiment
AU: * Butler, C F
EM: Carolyn.F.Butler@nasa.gov
AF: SSAI @ NASA/Langley Research Center, 1 Enterprise Pkwy, Hampton, VA 23666, United States
AU: Browell, E V
EM: Edward.V.Browell@nasa.gov
AF: NASA Langley Research Center, MS 401A, Hampton, VA 23681, United States
AU: Hair, J W
EM: Johnathan.W.Hair@nasa.gov
AF: NASA Langley Research Center, MS 401A, Hampton, VA 23681, United States
AU: Fenn, M A
EM: Marta.A.Fenn@nasa.gov
AF: SSAI @ NASA/Langley Research Center, 1 Enterprise Pkwy, Hampton, VA 23666, United States
AU: Notari, A
EM: Anthony.Notari-1.nasa.gov
AF: SSAI @ NASA/Langley Research Center, 1 Enterprise Pkwy, Hampton, VA 23666, United States
AU: Kooi, S A
EM: Susan.A.Kooi@nasa.gov
AF: SSAI @ NASA/Langley Research Center, 1 Enterprise Pkwy, Hampton, VA 23666, United States
AU: Ismail, S
EM: Syed.Ismail-1.nasa.gov
AF: NASA Langley Research Center, MS 401A, Hampton, VA 23681, United States
AU: Avery, M A
EM: Melody.A.Avery@nasa.gov
AF: NASA Langley Research Center, MS 401A, Hampton, VA 23681, United States
AU: Pierce, R B
EM: Brad.Pierce@noaa.gov
AF: NOAA/NESDIS/STAR - CIMSS, University of Wisconsin, Madison, WI 53201, United States
AB: The NASA Langley Research Center's Differential Absorption Lidar (LaRC/DIAL) system has been used to measure ozone and aerosol distributions in many airborne global tropospheric and stratospheric campaigns since 1980. The tropospheric configuration of this system was flown on the NASA DC-8 during the INTEX-B (Phase-I)/MILAGRO (I/M) field experiment, which was conducted from 24 February to 22 March 2006 over Mexico and the Gulf of Mexico. DIAL remote profile measurements were made from near the surface to above the tropopause along the flight track of the DC-8 with a small data void region of 750 m above and below the aircraft. Aerosol scattering ratios were determined at two wavelengths for a gross estimation of the relative size of the observed particles and measurements of aerosol depolarization were made to distinguish nonspherical aerosols, such as dust and some aerosols in aged fire plumes. In situ measurements of ozone from the FASTOZ instrument on the DC-8 were used to constrain the interpolation of the nadir and zenith ozone lidar measurements, which then provided an estimate of the entire tropospheric ozone profile along the flight track. A first order correction for aerosol attenuation was made to the aerosol profiles by using an assumed extinction-to- backscatter ratio to better characterize the attenuation by thick aerosol layers. The DIAL system was used to determine the large-scale variability and context of air masses being sampled in situ on the DC-8 and to direct the in situ sampling strategy in real time. Plumes from biomass burning in southern Mexico were often observed in the free troposphere over the Gulf of Mexico and over eastern Mexico. The Mexico City (MC) pollution plume was readily apparent with high ozone (>100 ppbv), high aerosol scattering (S>20), and enhanced aerosol depolarization (D>10%). The top of the MC pollution extended to a depth of about 2.5 km AGL. Some observations showed the MC plume spilling out over the mountains to neighboring regions, but the long-range transport of the MC plume was not readily apparent in the airborne lidar data. This presentation discusses these results and the types and characteristics of aerosol and ozone plumes that were encountered during this field experiment.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 0368 Troposphere: constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting