Ozone Data Figure 1 displays ozone mixing ratio curtains (in ppbv) from soundings taken during DISCOVER-AQ over Beltsville (upper) and Edgewood (lower), MD. Tropo- pause (in white ) is an ozonopause; boundary layer height (BLH) is given by *. Figure 1.

Figure 5.

Background & Goals We have used daily ozonesondes from Intensive Ozone Network Study experiments in 2004, 2006, 2008 [Thompson et al., 2007; 2011] to study the interaction of ozone and dynamical variability through Laminar Identification (LID) analysis combined with meteorological fields and to evaluate satellite derived tropospheric ozone column amounts [Doughty et al., 2011]. DISCOVER-AQ (Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality) in Maryland during July 2011 included 25 ozonesonde launches near Washington, DC, at the Howard University Beltsville Research Facility (“BV”), and 39 launches at Edgewood, Maryland (“EW”). We examined these soundings in detail to answer specific questions: -- How do overpass ozone column amounts derived from OMI compare to sonde ozone? -- How do boundary layer (BL) heights and ozone amounts compare at the two locations? -- What do LID budgets and P-3 aircraft spirals say about influences on ozone at BV and EW? -- How do 2011 BV influences compare to 2006-2010?

Results: Meteorological Variations in 2006-2011 Figure 6. In Figure 6 500mb geopotential height anomalies for 2006-2011 help identify potential meteorological causes of tropospheric ozone budget variability (as in Table). The years 2008 and 2009 display the lowest 500mb heights, likely from a more active wave pattern. Consequently, as the Table indicates, the highest average RW amounts show up for those summers at BV.

Anne M. Thompson*, R. M. Stauffer, S. K. Miller, D. K. Martins, Penn State University; * now at NASA/GSFC

E. Joseph, Howard Univ; A. J. Weinheimer, NCAR; G. S. Diskin, NASA/LaRC

Conclusions • Profound variation in meteorological influences on ozone

profiles as observed in soundings during DISCOVER-AQ is manifested in (1) differences between two Maryland sites only 70 km apart; (2) in Laminar (LID) budgets at each site; (3) in rapid day-to-day changes. The challenge implied for satellite tropospheric ozone retrievals is significant.

• Aircraft profiles of CO, NOy and water vapor measurements of the soundings add considerable information for interpretation of ozone variability.

• The 2006-2011 Beltsville ozone profile record reflects year-to-year meteorological variations that are corroborated by geopotential height fields, cloud cover, moisture, etc.

Literature Cited Doughty, D. C., et al., An intercomparison of tropospheric ozone retrievals derived from

two Aura instruments and in-situ measurements in western North America in 2006, J. Geophys. Res.,doi: 116, D06303, 10.1029/2010JD014703, 2011.

Pierce, R. B., and W. B. Grant, Seasonal evolution of Rossby and gravity wave induced laminae in ozonesonde data obtained from Wallops Island, Virginia. Geophys. Res. Lett., 25, 1859-1862, 1992.

Stauffer, R. M., et al.: Bay breeze influence on surface ozone at Edgewood, MD during July 2011, J. Atmos. Chem., doi: 10.1007/s10874-012-9241-6, 2012.

Thompson, A. M., et al.: Intercontinental Transport Experiment Ozonesonde Network Study (IONS, 2004): 1. Summertime upper troposphere/lower stratosphere (UT/LS) ozone over northeastern North America, J. Geophys. Res., 112, D12S12, doi: 10.1029/2006JD007441, 2007.

Thompson, A. M., et al., Strategic ozone sounding networks: Review of design and accomplishments, Atmos. Environ., doi:10.1016/j. atmosenv.2010.05.002, 45, 2145-2163, 2011.

Thompson, A. M., R. M. Stauffer, et al., Ozone profiles in the Baltimore-Washington region (2006-2011): Satellite comparisons and DISCOVER-AQ observations, J. Atmos. Chem., joch-13-0007, submitted, 2013.

Acknowledgments Thanks to AQAST Grant NNX11AQ44G and DISCOVER-AQ (NASA Grant NNX10AR39G) to

Penn State for support of this research. Additional grant support was provided by NASA through the Howard University BCCSO and Tropospheric Chemistry (NASA Grant NNX08AJ15G) . The DISCOVER-AQ project at NASA/Langley (J. H. Crawford & M. M. Kleb) is gratefully acknowledged.

In Figure 5 we see that sonde O3 profiles and fast O3 on the NASA P-3 agree quite well; note the P-3 samples to 3.5 km over EW and only 1.5 km over BV (black and gray traces in lower left panel of each set of four (upper 4 panels = 2 July; lower 4 panels = 14 July 2011). On 2 July the sondes (profiles of O3, RH, PT) display locally elevated O3 in dry layers; this signifies stratospheric air (RW, pink bands, in Figure 4, both sites). However, a bay breeze circulation pattern [Stauffer et al., 2012] causes an increase in BL O3 over EW - to 120 ppbv; this does not develop at BV. The lowest ozone amounts in total column occurred with cleaner conditions (CO, NOy) on 14 July.

Ozone Profiles in the Baltimore-Washington Region (2006-2011): Satellite Comparisons and DISCOVER-AQ Observations

Results: DISCOVER-AQ LID Budgets, Beltsville LID, 2006-2011 Figure 4. In Figure 4 LID budgets for 2011 over Edgewood are displayed (upper frame). The LID budgets are based on assigning segments within each profile to BL, Gravity Wave (GW) and Rossby Wave (RW) by the technique of Pierce and Grant [1998] and Thompson et al. [2007, 2011, 2013]. Compared to the Beltsville DISCOVER-AQ budgets (right frame, 2011 values on right) there is more Gravity Wave (GW, light blue) influenced ozone as a fraction of the total tropospheric ozone over Edgewood (left). This means more vertical mixing and possibly convection. Note that surface ozone values tend to be higher at EW than BV but the BL column is less at EW because BL height is ~25% lower at EW than over BV. The Table compares GW, RW influences over BV from 2006-2011.

Results: Satellite Comparisons & Profile Variability Figure 2 (above) comparisons of the OMI/MLS TTOR product are closer to the sondes at Beltsville than at Edgewood. Mean of ozone (below, Figure 3) at the two sites indicates the sonde ozone being much greater than TTOR could arise from higher BL ozone at Edgewood (compare Stauffer et al. POSTER on bay breeze impacts at EW).

Figure 3.

Year BL (DU, %) GW (DU, %) RW (DU, %) Residual (DU,%) Total (DU)

BV, 2006 9.36, 17.8 8.90, 17.0 15.6, 29.8 18.6, 35.4 52.4

BV, 2007 10.7, 19.5 5.70,10.4 15.7, 28.8 22.6, 41.3 54.6

BV, 2008 11.7, 21.2 5.88, 10.6 17.9, 32.3 19.9, 35.9 55.3

BV, 2009 9.74, 17.4 9.12, 13.1 21.9, 39.2 15.1, 27.0 55.9

BV, 2010 10.4, 17.6 7.73, 13.1 17.4, 29.5 23.6, 39.8 59.1

BV, July 2011 11.2, 18.9 7.76, 13.1 16.3, 27.3 24.2, 40.7 59.5

EW, All July 2011 8.66, 15.2 8.51, 14.9 17.6, 30.8 22.3, 39.1 57.1

EW, BV days only 9.37, 16.1 11.5, 19.8 15.0, 25.9 22.2, 38.2 58.1

Figure 5