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 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 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 PBL 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. Measurement Example I An unusual nighttime ozone enhancement in the PBL 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. Mike Newchurch 1, Shi Kuang 1, John Burris 2 1 University of Alabama in Huntsville, 2 NASA/Goddard 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 0.3 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 0.3 to 5 km. The detection system uses both photon counting and analog modes to maximize the dynamic ranges over both telescope systems. Until a third wavelength channel is added, an iterative aerosol correction procedure is applied to reduce the retrieval error arising from differential aerosol backscatter in the lower troposphere. This procedure iteratively substitutes the ozone profile from the DIAL algorithm back to the off-line (291) signal to calculate the aerosol extinction profile by assuming an appropriate lidar ratio. Then, the correction terms due to differential aerosol backscatter and extinction can be derived using Browell [1985]’s approximation by assuming an Angstrom exponent. Introduction The tropospheric ozone Differential Absorption Lidar (DIAL) developed jointly by University of Alabama in Huntsville and NASA/GSFC measures ozone profiles from 0.3 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 0.3 to 5 km. The detection system uses both photon counting and analog modes to maximize the dynamic ranges over both telescope systems. Until a third wavelength channel is added, an iterative aerosol correction procedure is applied to reduce the retrieval error arising from differential aerosol backscatter in the lower troposphere. This procedure iteratively substitutes the ozone profile from the DIAL algorithm back to the off-line (291) signal to calculate the aerosol extinction profile by assuming an appropriate lidar ratio. Then, the correction terms due to differential aerosol backscatter and extinction can be derived using Browell [1985]’s approximation by assuming an Angstrom exponent. 10-min Variations in PBL/FT Ozone from DIAL Measurements in Huntsville Nd:YAG pumped Dye laser Nd:YAG 4 16” Telescope Aft Optics Licel Computer PMT Nd:YAG pumped Dye laser 299 4” Telescope Hz, 4mJ/pulse Future Figure 1. RAPCD-DIAL configuration Figure 2. Dye laser EOS AURA Science Team Meeting, Leiden, The Netherlands, September aerosol ext., small-telescope 915 ceilometer backscatter Figure 6. Ozone and aerosol variations observed by RAPCD ozone DIAL on June 30, (a) Ozone retrieval. (b) Calculated aerosol extinction coefficient at 291nm. Figure 3. DIAL measurement during Oct. 4-5, (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, Figure 5. DIAL measurement during Aug , (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 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. This lidar well characterizes the atmospheric variations of ozone and aerosol fields that must be observed by the GEO-CAPE instrument suite for air-quality science and forecasting. Conclusion These time-series 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. This lidar well characterizes the atmospheric variations of ozone and aerosol fields that must be observed by the GEO-CAPE instrument suite for air-quality science and forecasting. Ozonesonde High ozone High aerosol Sunset Increasing aerosol Incoming ozone plume Upper tropospheric ozone plume