An Interagency Research Initiative for Ground-Based Lidar Profiling of Tropospheric Ozone and Aerosols CENRS Air Quali

1. An Interagency Research Initiative for Ground-Based Lidar Profiling of Tropospheric Ozone and Aerosols CENRS Air Quality Research Subcommittee Nov. 17, 2011 Washington, DC Mike Newchurch1, Jay Al-Saadi2, R. J. Alvarez3, John Burris4, John Hair5, Russell DeYoung5, Mike Hardesty3, Shi Kuang1, A. O. Langford3, Stuart McDermid6,Tom McGee4, Christoph Senff3, Jim Szykman7, Gail Tonnesen7 1UAHuntsville 2NASA/HQ 3NOAA/ESRL 4NASA/GSFC 5NASA/LaRC 6NASA/JPL 7USEPA

2. ABSTRACT Surface air quality is affected by pollution aloft through various physical and photochemical processes in and near the boundary layer. Unfortunately, the general lack of high-resolution observations above the surface limits our knowledge of the extent of these impacts. A recently started initiative will deploy ground-based lidar systems at several locations across the US to obtain more frequent observations of ozone and aerosol profiles for research assessments. Initial sites (UA Huntsville, NASA/GSFC, NASA/LaRC, NASA/JPL, NOAA/ESRL) were selected to take advantage of existing capabilities and will provide observations over a diverse range of air-quality environments. Two or three of these instruments will also be mobile so that they can be deployed to other locations. This initiative will provide a prototype for high-resolution time/height measurements of ozone and aerosols from near surface to the top of the troposphere with particular focus on the PBL. The conventional lowest altitude of ground based lidar observations is about 500 m above the surface. A goal of this activity is to develop a mini receiver to extend the measurements down to ~100 m above ground. Another objective is to develop recommendations for lowering the cost and improving the robustness of such systems to better enable their possible use in future national networks. These measurements can potentially make significant contributions in evaluating air-quality models and improving their simulation and forecasting capabilities. They will also provide high time-resolved observations to begin preparing for GEO-CAPE satellite mission observations expected early in the next decade. • NASA has provided initial organization and funding of this activity. NOAA, EPA, and public/private partnerships are also providing significant funding. Near term objectives include deployment of the ESRL system during the winter 2012 Uintah Basin Ozone study and operation of the other systems at their home institutions during 2012. It is anticipated that all data acquired will be archived and provided in common formats to the broader air-quality community for evaluation and assessment and use in air-quality models.

3. I. Motivation for prototype ozone lidar network measurements PBL Processes, especially those involving the diurnal pumping of the boundary layer, are the scientific key to understanding regional/local interactions resulting in surface ozone. Understanding the spatio-temporal complexity of these physical and chemical processes demands observations at high spatial (initially vertical) and temporal resolution. Ozonesondes are extensively used in various atmospheric chemistry studies because of their low upfront cost and well-characterized behavior. However, the whole process for a sonde launch typically requires four hours. And four-hour ozonesonde resolution is prohibitively expensive. We therefore consider lidars to provide the necessary spatial and temporal resolution. GEO-CAPEwill measure tropospheric gases and aerosols at ~8km and hourly resolution. Vertical resolution is on the order of 5-10kmin the troposphere. This vertical resolution is inadequate to resolve laminar structures that characterize tropospheric ozone and aerosols. Furthermore, GEO-CAPE information content in the PBL will likely be inadequate to resolve the processes responsible for air quality variability. We seek, therefore, to understand how the spaceborne measurements may be complemented with a ground-based measurement system.

4. I. Motivation for prototype ozone lidar network measurements (con’t) Air quality models are critical for supporting important policy decisions. Unfortunately, the general lack of high-resolution observations aloft limits the evaluation of air-quality models. The lidar profiling measurements can make significant contributions in evaluating air-quality models and improving their simulation and forecasting capabilities. Recent National Research Council reports, Global Sources of Local Pollution: An Assessment of Long-Range Transport of Key Air Pollutants to and from the United States (NRC, 2009) and Observing Weather and Climate from the Ground Up: A Nationwide Network of Networks (NRC, 2009), highlighted the need for chemical and physical measurements through the atmosphere, with the later report highlighting vertical profiles and measurements of composition aloft as among the “highest priority observations needed to address current inadequacies.” and specifically calls for an enhanced lidar network.

5. Comparison of the techniques for ozone observation a For OMI tropospheric ozone retrieval [Liu et al. 2010], [Worden et al. 2007]. b For ground-based only. The airborne lidar system can measure ozone with a 600-m spatial resolution, e.g., [Langford et al. 2011]. c For ground-base system, e.g., Sunnesson et al.1994; Proffitt and Langford 1997; Kuang et al. 2011. The temporal resolution is strongly related to the retrieval uncertainty. Generally longer integration time will reduce the uncertainty arising from statistical error. d The estimated cost is based on $800/launch and launching 6 sondes every day.

6. O3 measurements with 4-hour temporal resolution

7. Lidar ozone curtain with10-minute resolution ozonesonde

8. II. Air-Quality Lidar-Network Working Group (AQLNWG)

9. Partners • NASA R&A initiated and invited participation in AQLNWG: • NASA/GSFC, LaRC, JPL, NOAA/ESRL, USEPA, UAH. • Funding • NASA providing funding to adapt existing instruments, begin acquiring data, archive data, and facilitate data use. • NOAA and EPA coordination with private partners providing funding for instrument conversion, deployment, data analysis. • Agency roles • NASA: Historical funding of several lidar programs and GEO-CAPE satellite program. • NOAA: Funding of ESRL lidar group, AQ campaigns, NESDIS satellite programs. • EPA: Principal user and policy driver, developing IT infrastructure for routine use of data.

10. Purpose of the AQLNWG Provide high-resolution time-height measurements of ozone and aerosols at a few sites from near surface to upper troposphere for scientific investigations of air-quality processes and GEO-CAPE mission definition. Develop recommendations for lowering the cost and improving the robustness of such systems to better enable their possible use in future national networks to address the needs of NASA, NOAA, EPA and State/local AQ agencies.

11. Charge to the AQLNWG • Is a lidar network for air-quality measurements a high priority for advancing the state of the science? How would a NASA demonstration activity fit into monitoring needs/plans for other agencies and the nation? Can it fulfill needs for satellite retrieval algorithm development and cal/val? • Instrument hardware: Is a commercial solution available or imminent? What specific technology development may be required, and what mechanism is appropriate (e.g., NASA Centers, SBIR)? How soon could candidate instruments be available? Do we know these things, or should an RFI be issued? • What are the desired performance characteristics for: concentration, extinction, altitude range, sensitivity, measurement frequency, etc.? • What are the desired network characteristics: How many instruments would be needed for adequate demonstration? Where should they be located? Should portability be an emphasis? Consider value added by co-location within other networks (GALION, AERONET, MPLNET, profilers, AQ monitoring, supersites). • Synergies with other activities (field campaigns, e.g., Discover-AQ; routine aircraft profiling (MOZAIC/ IAGOS)). Assessment/improvement of CMAQ modeling. Integrated network system design strategy. Roles of different agencies/organizations.

12. Science Investigations that the AQLNWG will address • Provide high spatio-temporal observations of PBL and FT ozone and aerosol for use by the GEO-CAPE science team to study the character of the atmospheric structure that GEO-CAPE will observe and assess the fidelity with which a geo instrument can measure that structure. • Discover new structures and processes at the PBL/FT boundary, especially in the diurnal variation of that interface. • Foster use of these high-resolution ozone and aerosol observations to improve the processes in air-quality forecast and diagnostic models. • Exploit synergy with DISCOVER AQ, thermodynamic profilers, MOZAIC/IAGOS, regulatory surface monitors, and other networks. • Improve our understanding of the relationship between ozone and aerosols aloft and surface ozone and PM values. [Fairlie et al., 2009] [Thompson, et al., 2008] [Morris, et al., 2010]. • Advance our understanding of processes controlling regional background atmospheric composition (including STE and long range transport) and their effect on surface air quality to prepare for the GEO-CAPE era.

13. Instruments and Locations • Technology considerations and Brassboard instruments: 4 lidar technology approaches (YAG pumped Raman cells, YAG pumped Ce:LiCAF tunable laser, YAG pumped dye laser, OPO. • Location. Begin with current expertise at their locations. Also develop mobile lidars. • Undertake minimal instrument configuration changes to allow focus on making ozone measurements from near surface to middle or upper troposphere at several different locations across the USA that span the variability space. • TMF: 2-color Raman-cell system downwind of Los Angeles. Reduce lower altitude to ~few hundred meters AGL. • ESRL: Boulder, CO, Convert a/c TOPAZ lidar to ground-based scanning mobile instrument. • UAH: Huntsville, AL, Implement 3-color Raman-cell lidar and reduce lower altitude to ~200m AGL. • LaRC: Bring SESI Ce:LiCAF lidar to operation in a mobile configuration. • GSFC: Construct a 2-color Raman-cell lidar instead of OPO.

14. III. Scientific investigations addressed by the lidar network

15. Evolution of the Boundary Layer Ozone Maximum -lidar measurements and RAQMS model simulation (modeled by B. Pierce/NOAA/NESDIS/STAR/CIMSS) May 5 May 4 May 3, 2010 EPA surface Daytime PBL top collapsed May 01 May 02 May 03 May 04 May 05 May 06 May 07 May 08 Missed May 6 (high PBL O3) May 7

16. TOPAZ applications Pre-CalNex 2009: Orographic lifting & long-range transport of O3 originating in the Los Angeles Basin TMF lidar 48-h (solid) and 60-h (dotted) forward trajectories suggesting long-range transport aloft of O3 from Los Angeles to Utah and Colorado. Langford, A. O., et al., 2010: Long-range transport of ozone from the Los Angeles Basin: A case study, Geophys. Res. Lett., doi:10.1029/2010GL042507. SMOG model predictions (top) compared with TOPAZ lidar observations (bottom).

17. O3 Transport: Nocturnal O3 enhancement associated with low-level jet Co-located wind profiler Kuang et al. Atmospheric Environment 2011 Low-level jet Higher increasing rate of the surface O3 due to the low-level transport on the previous day Lidar Oct. 4, 2008 Oct. 1, 08 Oct. 2, 08 Oct. 4, 08 Oct. 3, 08 Positive correlation of ozone and aerosol due to transport Co-located ceilometer backscatter Aerosol Oct. 6, 08 Oct. 5, 08 Surface O3 and convective boundary layer height

18. Stratosphere-to-troposphere transport and its CMAQ Model simulation, Nov. 5, 2010 Modeled by ArastooPour-Biazar/UAH GOME total O3 Nov. 5 Huntsville Lidar O3 Stratospheric O3, zero RH Sonde Ozonesonde showing the high O3 and dry layer Local time

19. Stratospheric contribution to high surface ozone in Colorado during springtime A.O. Langford, K.C. Aikin1, C.S. Eubank1, E.J Williams1 Chemical Sciences Division ESRL, NOAA, Boulder, Colorado USA 1also at Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado, USA. Tropospheric Stratospheric Langford NOAA/ESRL/CSD

20. E.J. Williams Surface O3 and CO anticorrelated Langford NOAA/ESRL/CSD

21. CDPHE and NPS monitors Surface O3 increased from 55 to 100 ppbv in RMNP! Langford NOAA/ESRL/CSD

22. High-resolution PBL lidar observation suggests both UV and Vis radiances required to capture significant PBL signal for satellite Huntsville lidar observation on Aug. 4, 2010 Lidar obs. convolved with OMI UV averaging kernel---- unable to capture the highly variable ozone structure in PBL Lidar obs. Convolved with OMI UV-Vis averaging kernel----Captures the PBL ozone structure. X. Liu et al.

23. Zhang et al. (2011) Improved estimate of the policy-relevant background ozone in the United States using the GEOS-Chem global model with ½ by 2/3 degree horizontal resolution over North America; Atmospheric Environment 45: 6769-6776.

24. JPL/TMF ozone & water vapor lidars O3 H2O Ozone (left) and water vapor (Right) with 10 minute resolution showing the progression of a stratospheric intrusion and the anti-correlation between ozone and water. S. McDermid

25. EPA as an end user is developing infrastructure for routine use of 3-D measurements under their Remote Sensing Information Gateway US EPA Remote Sensing Information Gateway (RSIG)now provides the functions envisioned by 3D-AQS. 3D Air Quality System (3D-AQS): NASA Applied Science Project focused on increasing access and use of satellite and lidar data within the Air Quality Community. Satellite PI – Ray Hoff, UMBC LIDAR

26. IV. Sites and hardware configurations

27. Initial sites of the ground-based lidar network to provide O3 and aerosol data for air-quality study and GEO-CAPE mission Ancillary site info: TMF: sondes, ESRL: weekly sondes UAH: weekly sondes, miniMPL, physical profilers (T, U, ceilometer), dual-pol radar. LaRC: sondes (WFF), PANDORA, aerosol lidar, sfc Nox, NO2, O3, CO, SO2, PM2.5, met. GSFC: aerosol lidar, sun photometer, PANDORA, sondes (WFF) NOAA/ESRL NASA/GSFC NASA/LaRC JPL/TMF UAH 27

28. UAHuntsville planned configuration3 receiver channels covering 0.1-12km • 3- λ ( 283-289-299) system to minimize aerosol interference • Adding a 1-inch mini receiver channel to reduce the lowest measurement altitude to ~100m from the current 500m • Expected operation by summer 2012 Schematic diagram of the future transmitters and receivers.

29. TOPAZ: NOAA’s airborne Ozone/Aerosol Lidar(TOPAZ = Tunable Optical Profiler for Aerosols and oZone) • Compact, light-weight, all solid state lidar • 3 tunable UV wavelengths • Designed for nadir-looking deployment on NOAA Twin Otter • Measures ozone and aerosol backscatter profiles • Altitude coverage: from near the surface up to 5 km MSL • Resolution (O3): 90 m vertical, 600 m horizontal • Precision (O3) : 2-15 ppb

30. TOPAZ modifications for ground-based, scanning operation • Invert telescope to zenith-looking • Install in truck with roof top scanner

31. Scan strategy & expected performance of ground-based TOPAZ ~4 km AGL 3-angle scan sequence designed to provide composite O3 profiles from 17 m to approx. 4 km AGL. Horizontal stares will be performed occasionally. 90º 10º 2º 17 m AGL • Anticipated instrument performance • Time resolution: 1 min per angle; 5 min per scan sequence • Range/altitude resolution: 90 m; 3 – 90 m • Range/altitude coverage: 400 m – 4 km; 17 m – 4 km AGL • Precision: 1 – 10 ppb (SNR and range dependent)

32. Deployments of ground-based TOPAZ in FY 2012 • Uintah Basin Ozone Study (UBOS) • The UBOS study is designed to examine in detail the role of local atmospheric chemistry and meteorology in producing high wintertime O3 concentrations in the Uintah Basin in NE Utah. • TOPAZ will provide horizontal and vertical profiles of ozone as well as estimates of boundary layer height. • Time frame: February/March 2012 • 2. Local measurements (Boulder, Fritz Peak) • TOPAZ will measure vertical profiles of ozone at regular intervals at NOAA/ESRL in Boulder or at the Fritz Peak Observatory to a) provide a vertical context for the routine surface O3 observations in the greater Denver area and b) extend the record of mid-tropospheric ozone profile measurements by Langford et al. from the 1990s. • Time frame: April – September 2012

33. Comparison of the target configurations of the O3 lidars at different sites

34. Conclusions • Ozone/aerosol lidar research initiative will address compelling science questions of regional/local processes controlling air quality • Sub-hourly temporal-resolution processes • Laminar structures associated with regional and long-range pollutant transport and stratospheric influence • Surface interaction with residual O3 aloft and diurnal PBL pumping • These measurements will be used to • Measure the impact of ozone aloft on surface ozone over a diverse range of air-quality environments in the US • Evaluate air quality models to improve their simulation and forecasting capabilities • Identify cases of overwhelming O3 transport or exceptional events for regulatory analysis. • Provide high time-resolved observations to begin preparing for GEO-CAPE satellite mission observations expected early in the next decade • Inform future discussion about whether such measurements are needed routinely • Leveraging significant current instrumentation and expertise provides a cost effective way to obtain these research observations • Interagency interest and participation, and engagement of non-Federal partners to address high-priority research gaps, enhances the probability of effective outcome

35. Backup

36. LaRC ozone lidar Telescope Lidar Control DAQ System Receiver Box Laser Transmitter 1. Ground-based, but can be modified to a mobile system 2. Tunable two wavelengths within 282-313 nm for O3 measurement 3. 527nm for aerosol measurement

37. TOPAZ applications TexAQS 2006: Quantifying horizontal transport of O3 downwind from Houston and Dallas Cross sections of ozone downwind of Houston measured with TOPAZ on 08/14/2006. Ozone fluxes are computed for each transect by integrating above-background ozone across the plume and multiplying with horizontal wind speed measured with radar wind profilers. Ozone fluxes as a function of plume age downwind from Houston and Dallas (includes data from TexAQS 2000). Senff, C. J. et al., 2010: Airborne lidar measurements of ozone flux downwind of Houston and Dallas, J. Geophys. Res., 115, D20307, doi:10.1029/2009JD013689.