Institute of Atmospheric Physic Differential Absorption Lidar to Measure Tropospheric Ozone Variations Shi Kuang1, Mike Newchurch1, John Burris2, Steve Johnson3 1University of Alabama in Huntsville 2NASA-Goddard Space Flight Center 3NASA-Marshall Space Flight Center kuang@nsstc.uah.edu http://nsstc.uah.edu/atmchem Institute of Atmospheric Physic Beijing, China 30 August 2010

Institute of Atmospheric physic Outline Introduction Lidar hardware Measurement examples Future design Conclusion Institute of Atmospheric physic Beijing, China , August 2010

Institute of Atmospheric physic Introduction The common techniques to measure ozone profile: ozonesonde satellite lidar. NOAA, NASA, United Nations Environment Programme, WMO, “Scientific Assessment of Ozone Depletion: 2002”. Institute of Atmospheric physic Beijing, China , August 2010

Institute of Atmospheric physic Introduction Ozonesonde Measuring O3 up to 35km ~5m/s rising rate, ±10% uncertainty, 100-m vertical resolution Strength: well-characterized, low up-front cost, good vertical resolution, OK for cloudy sky, simultaneous T/P/RH. Weakness: long preparation time, drifting with wind. UAHuntsville 2010 earth day launch Institute of Atmospheric physic Beijing, China , August 2010

11-year and >600 ozonesonde profiles at Huntsville, AL, U.S.A. Introduction Ozonesonde O3 mixing ratio (top) and RH (bottom) 11-year and >600 ozonesonde profiles at Huntsville, AL, U.S.A. Institute of Atmospheric physic Beijing, China , August 2010

Institute of Atmospheric physic Introduction Satellite Strength: good for column O3, global distribution Weakness: low vertical resolution (several km), cloud contamination Liu et al. 2005 Institute of Atmospheric physic Beijing, China , August 2010

Institute of Atmospheric physic Introduction Lidar ground-based, aircraft-based, mobile Strength: continuous measurement, high temporal resolution Weakness: cloud contamination, expensive, can’t measure surface for ground-based JPL-Table Mountain Facility http://tmf-lidar.jpl.nasa.gov/index.htm Institute of Atmospheric physic Beijing, China , August 2010

Motivation of O3 lidar measurement Introduction Motivation of O3 lidar measurement Provide high-resolution ozone observation needed by atmospheric modeling, satellite validation, and air quality studies. Institute of Atmospheric physic Beijing, China , August 2010

DIff. absorption lidar (DIAL) concept Introduction DIff. absorption lidar (DIAL) concept Backscattering Medium O3 DIAL Equation R σ P R R1 R2 On Off λ λon λoff Δσ Laser Telescope Institute of Atmospheric physic Beijing, China , August 2010

Institute of Atmospheric physic Lidar hardware Typical composition Transmitter (266, 280-292, 308, 316, 351, 355nm for O3) Receiver (telescope and aft optics) Detector (photomutiplier (PMT) or avalanche photodiode (APD)) Signal processing (photoncounting or analog) 10 Institute of Atmospheric physic Beijing, China , August 2010

Institute of Atmospheric physic Lidar hardware Huntsville lidar 30Hz, 6 or 3mJ/pulse 285 291 16” Telescope 4” Telescope Measurement range 3 Web server 2 1 Aft Optics Computer 4 Nd:YAG pumped Dye laser PMT 5 Licel Nd:YAG pumped Dye laser RAPCD-DIAL configuration 11 Institute of Atmospheric physic Beijing, China , August 2010

Institute of Atmospheric physic Introduction Lidar lab setup Institute of Atmospheric physic Beijing, China , August 2010

Institute of Atmospheric physic Lidar hardware Transmitter Pump Dye laser Institute of Atmospheric physic Beijing, China , August 2010

Institute of Atmospheric physic Lidar hardware Receiver and detector PMT 16’’ Newtonian telescope 4’’ customized small telescope Institute of Atmospheric physic Beijing, China , August 2010

Institute of Atmospheric physic Measurement examples 1. Intense STE (~500ppbv at 7km) to reach top of the PBL (~2km) within 48 hours 500ppbv Cloud Cloud Cloud sonde Ozone lidar measurements with a 10-min temporal resolution and ~500-m vertical range resolution from 27 to 28 April 2010. Institute of Atmospheric physic Beijing, China , August 2010

Co-located ozonesonde measurements Measurement examples Co-located ozonesonde measurements Apr. 23, 2010 Apr. 27, 2010 May 1 2010 Tropopause Dry stratospheric air Institute of Atmospheric physic Beijing, China , August 2010

Institute of Atmospheric physic Measurement examples 2. PBL O3 maximum May 7 May 3, 2010 May 4, 2010 EPA surface O3 Sonde, 11:30 May 6 (high PBL O3) May 5 89ppbv, highest during 2010 so far Alt (km) Local time Aloft ozone in the PBL generally explains the daily surface maximum value although large differences between the surface and upper-air O3 often exist especially during nighttime. Institute of Atmospheric physic Beijing, China , August 2010

The 3rd Asia Pacific Radiation Symposium Lidar observation, Aug. 4, 2010 Convolution of lidar ozone measurements between the surface and 10 km altitude at Huntsville, AL during August 4, 2010 with OMI ozone averaging kernel and a priori indicates that OMI is unable to capture the highly variable ozone structure in PBL, but captures a significant portion of the mid-tropospheric layer Lidar convolved with OMI kernel Convolution of lidar ozone measurements between the surface and 10 km altitude at Huntsville, AL during August 4, 2010 with OMI ozone averaging kernel and a priori indicates that OMI is unable to capture the highly variable ozone structure in PBL because of its resolution limitation The 3rd Asia Pacific Radiation Symposium Seoul, South Korea 25-28 August 2010 Hey!! 18

Institute of Atmospheric physic Future plan shift one dye laser to 316 and add two Raman-shifted lasers at 289 and 299 so that we can extend the observations to upper troposphere. Apply dual-DIAL (289/299, 299/316) retrieval technique to further reduce aerosol interference in the lower troposphere. Schematic diagram of the future transmitters, wavelength pairs, and their measurement ranges. Institute of Atmospheric physic Beijing, China , August 2010

Institute of Atmospheric physics Future plan 3-λ dual DIAL technique [Kovalev and Bristow 1996, Wang et al. 1997] Dial Eqn. On1-off1 + On2-off2 -Cx Dual-DIAL Eqn. No assumption for lidar ratio and Angstrom! Institute of Atmospheric physics Beijing, China , August 2010

Raman cell for future transmitter Future plan Raman cell for future transmitter Big Sky (Quantel) 266 pump laser Raman gas cell 2-m Raman cell for future transmitter (289/299nm) Institute of Atmospheric physics Beijing, China , August 2010

Future receiving system for the wavelength Future plan Future receiving system for the wavelength Institute of Atmospheric physic Beijing, China , August 2010

Institute of Atmospheric physic Conclusions 1. Lidar measures high spatio-temporal ozone variations associated with different dynamic and photochemical processes from PBL to upper troposphere. 2. The ozone variations and structures sometimes are closely correlated with aerosol and sometimes not. 3. Nocturnal residual ozone layers often exist decoupled from the surface. 4. The lidar observations will be very helpful for addressing the ozone variability captured by geostationary satellites and forecast with regional air-quality forecasts. Institute of Atmospheric physic Beijing, China , August 2010

Institute of Atmospheric physic References Kuang, S., et al. (2010), Differential Absorption Lidar (DIAL) to measure sub-hourly variation of tropospheric ozone profiles, IEEE Trans. Geosci. Remote Sens., in press. Liu, X., K. Chance, C. E. Sioris, R. J. D. Spurr, T. P. Kurosu, R. V. Martin, and M. J. Newchurch, "Ozone profile and tropospheric ozone retrievals from Global Ozone Monitoring Experiment: Algorithm description and validation," J. Geophys. Res., 110, p. D20307, 2005. NOAA, NASA, United Nations Environment Programme, WMO, “Scientific Assessment of Ozone Depletion: 2002”, World Meteorological Organization Global Ozone Research and Monitoring Project - Report No. 47 Institute of Atmospheric physic Beijing, China , August 2010