1. Measurement Example III Figure 6 presents the ozone and aerosol variations under a light-aerosol sky condition. The intensity and structure of aerosol and ozone are not significantly correlated. Measurement Example II Both the ozone lidar 291-nm raw signal and ceilometer suggest an enhancing backscatter below 2.5 km after 14:00 due to the growing wet droplets before the raining. These aerosol activities do not have a significant correlation with the ozone structure because the cloud formation process does not change the ozone concentration significantly. Measurement Example I An unusual nighttime ozone enhancement in the lower troposphere accompanied with a similar aerosol structure appears in Figure 3. This growing aerosol layer is also observed by an independent ceilometer. The back trajectory calculation in Figure 4 suggests that pollution originating within the vicinity of Birmingham was the source and partly responsible for this ozone enhancement. Shi Kuang 1, Mike Newchurch 1, John Burris 2, Steve Johnson 3 1 University of Alabama in Huntsville, 2 NASA/Goddard Space Flight Center, 3 NASA/Mashall Space Flight Center Introduction The tropospheric ozone Differential Absorption Lidar (DIAL) developed jointly by University of Alabama in Huntsville and NASA/GSFC measures ozone profiles from 0.5 to ~8 km at 10-minute intervals with a vertical resolution less than 750 m. The transmitter consists of two identical dye lasers pumped by two separate, frequency-doubled Nd:YAG lasers. The receiving system operates a 40-cm Newtonian (large) telescope, which covers the altitude from 3 to 8 km, and a 10-cm Cassegrain (small) telescope, which covers the altitude from 0.5 to 5 km. The detection system uses both photon counting and analog modes to maximize the dynamic ranges over both telescope systems. A comparison of the lidar retrievals and coincident ozonesonde measurements suggests that retrieval accuracy ranges from better than 10% after the application of an aerosol correction below 4 km to 20% for altitudes below 8 km with 750- m vertical resolution and 10-min integration. 10-min Variations in PBL/FT Ozone from DIAL Measurements in Huntsville 285291 Nd:YAG pumped Dye laser Nd:YAG 4 16” Telescope Aft Optics Licel Computer PMT Nd:YAG pumped Dye laser 299 4” Telescope 5 1 2 3 20Hz, 4mJ/pulse Future Figure 1. RAPCD-DIAL configuration Figure 2. Dye laser 90 th AMS Annual Meeting, Atlanta, GA, Jan. 17-21, 2010. 291 aerosol ext., small-telescope 915 ceilometer backscatter Figure 6. Ozone and aerosol variations observed by RAPCD ozone DIAL on June 30, 2009. (a) Ozone retrieval. (b) Calculated aerosol extinction coefficient at 291nm. Figure 3. DIAL measurement during Oct. 4-5, 2008. (a) Ozone retrieval with 10-min temporal integration and 750-m vertical resolution as well as the coincident ozonesonde measurement at 18:01. (b) Calculated aerosol extinction coefficient at 291nm. (c) Co-located 915-nm ceilometer backscatter. Figure 4. Backtrajectories of 24 hours at 500, 1500, and 4000 m for the nighttime ozone enhancement event observed in Huntsville on Oct. 5, 2008. Figure 5. DIAL measurement during Aug. 17-18, 2008. (a) Range-corrected signal of 291-nm small-telescope channel. (b) Ozone retrieval with 10-min temporal integration and 750-m vertical resolution as well as two coincident ozonesonde measurements at 13:01 and 18:01. (c) Calculated aerosol extinction coefficient at 291nm. (d) Co-located 915-nm ceilometer backscatter. Conclusion These time-series lidar observations show a wide variety of evolving conditions including growing and diminishing, rising and sinking ozone layers that are sometimes associated with aerosol or water-vapor layers and sometimes not. Trajectory analyses indicate some cases of very sharp shear layers with very different sources and effects from widely disparate directions. Conclusion These time-series lidar observations show a wide variety of evolving conditions including growing and diminishing, rising and sinking ozone layers that are sometimes associated with aerosol or water-vapor layers and sometimes not. Trajectory analyses indicate some cases of very sharp shear layers with very different sources and effects from widely disparate directions. http://nsstc.uah.edu/atmchem Ozonesonde High ozone High aerosol Sunset Increasing aerosol Upper tropospheric ozone plume