1. Tropospheric ozone variations revealed by high resolution lidar M. J. Newchurch 1, John Burris 2, Shi Kuang 1, Guanyu Huang 1, Wesley Cantrell 1, Lihua Wang 1, Patrick I. Buckley 1, Xiong Liu 3, Debra Hopson 4 1 University of Alabama in Huntsville 2 Goddard Space Flight Center, NASA 3 Harvard Smithsonian Astrophysical Observatory 4 Huntsville Department of Natural Resources and Environmental Management The 3 rd Asia Pacific Radiation Symposium Seoul, South Korea 25-28 August 2010

2. 2Hey!! Introduction High frequency of the ozone layer occurs in ozonesonde and Lidar profiles. The ozone layer has high potential implications for a variety of dynamic, chemical atmospheric processes and energy budgets (Newell et. al,. 2001). Due to their significance, dynamics and chemistry models should reproduce the ozone laminar structure (Stoller et al., 1999, Newell et al., 2001, Thouret et al., 2001). However, we have little understanding of the mechanisms of ozone layers. (Stoller et al., 1999, Newell et al., 2001, Thouret et al., 2001). In this study, we use two independent methods (Gradients and Wavelets) to study the mechanisms of ozone layer and its applications to models and satellite retrievals. 2 The 3 rd Asia Pacific Radiation Symposium Seoul, South Korea 25-28 August 2010

3. 3 2007 3

4. 4Hey!!4 Using Difference Quotients to Find Extreme Points of Ozone Profiles Difference quotients are used to find extreme points of the mixing ratio. Local minima and maxima are filtered through to distinguish significant layers based on the threshold percent difference value. The threshold is defined as 15% difference between max and min. A 3-point boxcar average is applied to data before difference quotients are applied. Huntsville Ozonesonde Data 4 The 3 rd Asia Pacific Radiation Symposium Seoul, South Korea 25-28 August 2010

5. 5 Continuous Wavelet Transform(CWT) The CWT coefficient is defined as: a is the spatial extent or dilation of the function. b is the location at which the wavelet function is centered—the translation of the function. f(z) is the signal of interest, in this case, an ozone profile. and are the top and the bottom of the profile.  means wavelet function. 5 The 3 rd Asia Pacific Radiation Symposium Seoul, South Korea 25-28 August 2010

6. 6 CWT-Detected Layers from HSV Ozonesondes Where there is a large gradient in the profile, the absolute value of CWT coefficient will be large. Therefore, we use CWT to detect the upper and lower boundaries of the ozone layer. In order to delete the “noisy” layer, two thresholds are set: The max of these two should > 10.0% and the min should > 3.0%. is the max ozone mixing ratio (MR) within the layer. and are the ozone MR at the upper and lower boundaries of the layer. 6 The 3 rd Asia Pacific Radiation Symposium Seoul, South Korea 25-28 August 2010

7. 7 Fairbanks Pellston Trinidad Head Houston Huntsville Sable Island Lidar and Ozonesonde Facilities used in this investigation 7 The 3 rd Asia Pacific Radiation Symposium Seoul, South Korea 25-28 August 2010

8. 8 Seasonal Variations Occur in Altitudinal Distributions- Layer Height WRT to Tropopause Height Gradient Wavelet Spring Summer High frequency of layers below tropopause Low frequency of layers near tropopause Trinidad Head 8 The 3 rd Asia Pacific Radiation Symposium Seoul, South Korea 25-28 August 2010

9. 9 Layer Characteristics Vary Between Locations-Layer Height WRT to Tropopause Height (Wavelet) Decreasing Latitude Fairbanks (1996-1997, 2001; 64.86, -147.85) Pellston (2004; 45.59, -84.7) Sable Island (1997; 43.96, -60.05) Houston (2000; 29.75, -95.43 ) 9 The latitudinal trend of layer frequency below the tropopause is captured by both methods of analysis The frequency of layers above the tropopause decreases as latitude decreases; this is consistent for both methods as well The 3 rd Asia Pacific Radiation Symposium Seoul, South Korea 25-28 August 2010

10. Seasonal Peak Above Ground Level (Wavelets) Huntsville SpringSummer Fall Winter

11. 11 Layer B Thickness Max: 4.8 km Min: 3.0 km Mean Thickness: 0.3 km /10min +0.9 km /10min -0.3 km /10min Layer A Max-Min Max: 50.1 ppbv Min: 36.6 ppbv Mean max-min : 2.5 ppbv / 10min +7.9 ppbv / 10min -2.4 ppbv / 10min A B Temporal variability from other layer attributes can be similarly quantified. For example: O3 peak altitude, mixing ratio at peak. Fine structure in the temporal variations of layer attributes can be quantified by Wavelet and Gradient methods from Lidar observations. 11

12. 12Hey!! 1. Intense STE (~500ppbv at 7km) to reach top of the PBL (~2km) within 48 hours 12 The 3 rd Asia Pacific Radiation Symposium Seoul, South Korea 25-28 August 2010

13. 13 10min, 500m resolution O3 lidar retrieval sonde 500ppbv Cloud 13 Cold front passage, clouds at 4-6km sonde

14. 14Hey!! Apr. 23, 2010Apr. 27, 2010May 1, 2010 Dry stratospheric air Tropopause Co-located ozonesonde measurements 14 The 3 rd Asia Pacific Radiation Symposium Seoul, South Korea 25-28 August 2010

15. 15 http://nomads.ncdc.noaa.gov/ Huntsville Dry air tongue

16. NAM RH pressure-time cross-section above Huntsville http://nomads.ncdc.noaa.gov/ 12Z 26 April~ 00Z 30 April, 2010 Dry air intrusion lat:34.73, long: -86.65 16

17. 17Hey!! 2. PBL ozone maximum due to post-front air stagnation. High surface ozone was also observed by the EPA station in Huntsville. 17 The 3 rd Asia Pacific Radiation Symposium Seoul, South Korea 25-28 August 2010

18. 18Hey!! Sonde, 1PM, May 8 May 5, 2010 May 7, 2010 May 6, 2010 May 3, 2010 May 4, 2010 EPA surface O3 Decoupling of surface and residual layer Sonde 18 The 3 rd Asia Pacific Radiation Symposium Seoul, South Korea 25-28 August 2010

19. Ozone Lidar (CNRS) during the ESCOMPTE field Campaign (Marseilles area, summer 2001) MOCAGE (Météo-France) equivalent to Lidar observations Current models, even run at high resolution (10km and below) tend to underestimate above surface horizontal and vertical gradients as well as variability. This is a fundamental concern in the context of a changing climate : to what extent can we assess future evolutions (Air Quality, regional-scale radiative forcings,…)? Vincent-Henri.Peuch@meteo.fr on behalf of the MAGEAQ consortium

20. 20Hey!! 3. Correlation between ozone and aerosol 20 The 3 rd Asia Pacific Radiation Symposium Seoul, South Korea 25-28 August 2010

21. 21Hey!! Positively correlated due to transport (from the same source) Aerosol ext.coeff. at 291nm from O3 DIAL Co-located ceilometer backscatter Low-level jet Co-located wind profiler Positively correlated due to transport Oct. 4, 2008 21 The 3 rd Asia Pacific Radiation Symposium Seoul, South Korea 25-28 August 2010

22. 22Hey!! Ozone mixing ratio, August 4, 2010 Aerosol ext.n coeff. At 291nm from O3 DIAL Diurnal variation Different variation structures for ozone and aerosol suggest local photochemistry dominates the ozone production 22 The 3 rd Asia Pacific Radiation Symposium Seoul, South Korea 25-28 August 2010

23. 23Hey!! 23 4. Potential for using lidar measurements to address ozone variability captured by satellite The 3 rd Asia Pacific Radiation Symposium Seoul, South Korea 25-28 August 2010

24. 24Hey!! Lidar observation, Aug. 4, 2010 Lidar convolved with OMI kernel 24 The 3 rd Asia Pacific Radiation Symposium Seoul, South Korea 25-28 August 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

25. 25Hey!! 1. High spatio-temporal ozone variations are 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. Conclusions 25 The 3 rd Asia Pacific Radiation Symposium Seoul, South Korea 25-28 August 2010